Automating system administration by using RHEL System Roles

Red Hat Enterprise Linux 8

Consistent and repeatable configuration of RHEL deployments across multiple hosts with Red Hat Ansible Automation Platform playbooks

Red Hat Customer Content Services

Abstract

The Red Hat Enterprise Linux (RHEL) System Roles are a collection of Ansible roles, modules, and playbooks that help automate the consistent and repeatable administration of RHEL systems. With RHEL System Roles, you can efficiently manage large inventories of systems by running configuration playbooks from a single system.

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Chapter 1. Introduction to RHEL System Roles

RHEL System Roles is a collection of Ansible roles and modules. By using RHEL System Roles, you can remotely manage the system configurations of multiple RHEL systems across major versions of RHEL. To use it to configure systems, you must use the following components:

Control node
A control node is the system from which you run Ansible commands and playbooks. Your control node can be an Ansible Automation Platform, Red Hat Satellite, or a RHEL 9, 8, or 7 host. For more information, see Preparing a control node on RHEL 8.
Managed node
Managed nodes are the servers and network devices that you manage with Ansible. Managed nodes are also sometimes called hosts. Ansible does not have to be installed on managed nodes. For more information, see Preparing a managed node.
Ansible playbook
In a playbook, you define the configuration you want to achieve on your managed nodes or a set of steps for the system on the managed node to perform. Playbooks are Ansible’s configuration, deployment, and orchestration language.
Inventory
In an inventory file, you list the managed nodes and specify information such as IP address for each managed node. In the inventory, you can also organize the managed nodes by creating and nesting groups for easier scaling. An inventory file is also sometimes called a hostfile.

On Red Hat Enterprise Linux 8, you can use the following roles provided by the rhel-system-roles package, which is available in the AppStream repository:

Role nameRole descriptionChapter title

certificate

Certificate Issuance and Renewal

Requesting certificates using RHEL System Roles

cockpit

Web console

Installing and configuring web console with the cockpit RHEL System Role

crypto_policies

System-wide cryptographic policies

Setting a custom cryptographic policy across systems

firewall

Firewalld

Configuring firewalld by using System Roles

ha_cluster

HA Cluster

Configuring a high-availability cluster using System Roles

kdump

Kernel Dumps

Configuring kdump using RHEL System Roles

kernel_settings

Kernel Settings

Using Ansible roles to permanently configure kernel parameters

logging

Logging

Using the logging System Role

metrics

Metrics (PCP)

Monitoring performance using RHEL System Roles

microsoft.sql.server

Microsoft SQL Server

Configuring Microsoft SQL Server using the microsoft.sql.server Ansible role

network

Networking

Using the network RHEL System Role to manage InfiniBand connections

nbde_client

Network Bound Disk Encryption client

Using the nbde_client and nbde_server System Roles

nbde_server

Network Bound Disk Encryption server

Using the nbde_client and nbde_server System Roles

postfix

Postfix

Variables of the postfix role in System Roles

postgresql

PostgreSQL

Installing and configuring PostgreSQL by using the postgresql RHEL System Role

selinux

SELinux

Configuring SELinux using System Roles

ssh

SSH client

Configuring secure communication with the ssh System Roles

sshd

SSH server

Configuring secure communication with the ssh System Roles

storage

Storage

Managing local storage using RHEL System Roles

tlog

Terminal Session Recording

Configuring a system for session recording using the tlog RHEL System Role

timesync

Time Synchronization

Configuring time synchronization using RHEL System Roles

vpn

VPN

Configuring VPN connections with IPsec by using the vpn RHEL System Role

Additional resources

Chapter 2. Preparing a control node and managed nodes to use RHEL System Roles

Before you can use individual RHEL System Roles to manage services and settings, you must prepare the control node and managed nodes.

2.1. Preparing a control node on RHEL 8

Before using RHEL System Roles, you must configure a control node. This system then configures the managed hosts from the inventory according to the playbooks.

Prerequisites

  • RHEL 8.6 or later is installed. For more information about installing RHEL, see Performing a standard RHEL 8 installation.
  • The system is registered to the Customer Portal.
  • A Red Hat Enterprise Linux Server subscription is attached to the system.
  • If available in your Customer Portal account, an Ansible Automation Platform subscription is attached to the system.

Procedure

  1. Install the rhel-system-roles package:

    [root@control-node]# yum install rhel-system-roles

    This command installs the ansible-core package as a dependency.

    Note

    In RHEL 8.5 and earlier versions, Ansible packages were provided through Ansible Engine instead of Ansible Core, and with a different level of support. Do not use Ansible Engine because the packages might not be compatible with Ansible automation content in RHEL 8.6 and later. For more information, see Scope of support for the Ansible Core package included in the RHEL 9 and RHEL 8.6 and later AppStream repositories.

  2. Create a user named ansible to manage and run playbooks:

    [root@control-node]# useradd ansible
  3. Switch to the newly created ansible user:

    [root@control-node]# su - ansible

    Perform the rest of the procedure as this user.

  4. Create an SSH public and private key:

    [ansible@control-node]$ ssh-keygen
    Generating public/private rsa key pair.
    Enter file in which to save the key (/home/ansible/.ssh/id_rsa):
    Enter passphrase (empty for no passphrase): <password>
    Enter same passphrase again: <password>
    ...

    Use the suggested default location for the key file.

  5. Optional: To prevent Ansible from prompting you for the SSH key password each time you establish a connection, configure an SSH agent.
  6. Create the ~/.ansible.cfg file with the following content:

    [defaults]
    inventory = /home/ansible/inventory
    remote_user = ansible
    
    [privilege_escalation]
    become = True
    become_method = sudo
    become_user = root
    become_ask_pass = True
    Note

    Settings in the ~/.ansible.cfg file have a higher priority and override settings from the global /etc/ansible/ansible.cfg file.

    With these settings, Ansible performs the following actions:

    • Manages hosts in the specified inventory file.
    • Uses the account set in the remote_user parameter when it establishes SSH connections to managed nodes.
    • Uses the sudo utility to execute tasks on managed nodes as the root user.
    • Prompts for the root password of the remote user every time you apply a playbook. This is recommended for security reasons.
  7. Create an ~/inventory file in INI or YAML format that lists the hostnames of managed hosts. You can also define groups of hosts in the inventory file. For example, the following is an inventory file in the INI format with three hosts and one host group named US:

    managed-node-01.example.com
    
    [US]
    managed-node-02.example.com ansible_host=192.0.2.100
    managed-node-03.example.com

    Note that the control node must be able to resolve the hostnames. If the DNS server cannot resolve certain hostnames, add the ansible_host parameter next to the host entry to specify its IP address.

Next steps

2.2. Preparing a managed node

Managed nodes are the systems listed in the inventory and which will be configured by the control node according to the playbook. You do not have to install Ansible on managed hosts.

Prerequisites

  • You prepared the control node. For more information, see Preparing a control node on RHEL 8.
  • You have SSH access from the control node.

    Important

    Direct SSH access as the root user is a security risk. To reduce this risk, you will create a local user on this node and configure a sudo policy when preparing a managed node. Ansible on the control node can then use the local user account to log in to the managed node and run playbooks as different users, such as root.

Procedure

  1. Create a user named ansible:

    [root@managed-node-01]# useradd ansible

    The control node later uses this user to establish an SSH connection to this host.

  2. Set a password for the ansible user:

    [root@managed-node-01]# passwd ansible
    Changing password for user ansible.
    New password: <password>
    Retype new password: <password>
    passwd: all authentication tokens updated successfully.

    You must enter this password when Ansible uses sudo to perform tasks as the root user.

  3. Install the ansible user’s SSH public key on the managed node:

    1. Log in to the control node as the ansible user, and copy the SSH public key to the managed node:

      [ansible@control-node]$ ssh-copy-id managed-node-01.example.com
      /usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/home/ansible/.ssh/id_rsa.pub"
      The authenticity of host 'managed-node-01.example.com (192.0.2.100)' can't be established.
      ECDSA key fingerprint is SHA256:9bZ33GJNODK3zbNhybokN/6Mq7hu3vpBXDrCxe7NAvo.
    2. When prompted, connect by entering yes:

      Are you sure you want to continue connecting (yes/no/[fingerprint])? yes
      /usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
      /usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
    3. When prompted, enter the password:

      ansible@managed-node-01.example.com's password: <password>
      
      Number of key(s) added: 1
      
      Now try logging into the machine, with:   "ssh '<managed-node-01.example.com>'"
      and check to make sure that only the key(s) you wanted were added.
    4. Verify the SSH connection by remotely executing a command on the control node:

      [ansible@control-node]$ ssh <managed-node-01.example.com> whoami
      ansible
  4. Create a sudo configuration for the ansible user:

    1. Create and edit the /etc/sudoers.d/ansible file by using the visudo command:

      [root@managed-node-01]# visudo /etc/sudoers.d/ansible

      The benefit of using visudo over a normal editor is that this utility provides basic sanity checks and checks for parse errors before installing the file.

    2. Configure a sudoers policy in the /etc/sudoers.d/ansible file that meets your requirements, for example:

      • To grant permissions to the ansible user to run all commands as any user and group on this host after entering the ansible user’s password, use:

        ansible ALL=(ALL) ALL
      • To grant permissions to the ansible user to run all commands as any user and group on this host without entering the ansible user’s password, use:

        ansible ALL=(ALL) NOPASSWD: ALL

    Alternatively, configure a more fine-granular policy that matches your security requirements. For further details on sudoers policies, see the sudoers(5) man page.

Verification

  1. Verify that you can execute commands from the control node on an all managed nodes:

    [ansible@control-node]$ ansible all -m ping
    BECOME password: <password>
    managed-node-01.example.com | SUCCESS => {
        	"ansible_facts": {
        	    "discovered_interpreter_python": "/usr/bin/python3"
        	},
        	"changed": false,
        	"ping": "pong"
    }
    ...

    The hard-coded all group dynamically contains all hosts listed in the inventory file.

  2. Verify that privilege escalation works correctly by running the whoami utility on a managed host by using the Ansible command module:

    [ansible@control-node]$ ansible managed-node-01.example.com -m command -a whoami
    BECOME password: <password>
    managed-node-01.example.com | CHANGED | rc=0 >>
    root

    If the command returns root, you configured sudo on the managed nodes correctly.

Additional resources

Chapter 3. Installing and Using Collections

3.1. Introduction to Ansible Collections

Ansible Collections are the new way of distributing, maintaining, and consuming automation. By combining multiple types of Ansible content such as playbooks, roles, modules, and plugins, you can benefit from improvements in flexibility and scalability.

The Ansible Collections are an option to the traditional RHEL System Roles format. Using the RHEL System Roles in the Ansible Collection format is almost the same as using it in the traditional RHEL System Roles format. The difference is that Ansible Collections use the concept of a fully qualified collection name (FQCN), which consists of a namespace and the collection name. The namespace we use is redhat and the collection name is rhel_system_roles. So, while the traditional RHEL System Roles format for the kernel_settings role is presented as rhel-system-roles.kernel_settings (with dashes), using the Collection fully qualified collection name for the kernel_settings role would be presented as redhat.rhel_system_roles.kernel_settings (with underscores).

The combination of a namespace and a collection name guarantees that the objects are unique. It also ensures that objects are shared across the Ansible Collections and namespaces without any conflicts.

Additional resources

  • To use the Red Hat Certified Collections by accessing the Automation Hub, you must have an Ansible Automation Platform (AAP subscription).

3.2. Collections structure

Collections are a package format for Ansible content. The data structure is as below:

  • docs/: local documentation for the collection, with examples, if the role provides the documentation
  • galaxy.yml: source data for the MANIFEST.json that will be part of the Ansible Collection package
  • playbooks/: playbooks are available here

    • tasks/: this holds 'task list files' for include_tasks/import_tasks usage
  • plugins/: all Ansible plugins and modules are available here, each in its subdirectory

    • modules/: Ansible modules
    • modules_utils/: common code for developing modules
    • lookup/: search for a plugin
    • filter/: Jinja2 filter plugin
    • connection/: connection plugins required if not using the default
  • roles/: directory for Ansible roles
  • tests/: tests for the collection’s content

3.3. Installing Collections by using the CLI

Collections are a distribution format for Ansible content that can include playbooks, roles, modules, and plugins.

You can install Collections through Ansible Galaxy, through the browser, or by using the command line.

Prerequisites

  • Access and permissions to one or more managed nodes.
  • Access and permissions to a control node, which is a system from which Red Hat Ansible Core configures other systems.

    On the control node:

    • The ansible-core and rhel-system-roles packages are installed.
    • An inventory file which lists the managed nodes.

Procedure

  • Install the collection via RPM package:

    # yum install rhel-system-roles

After the installation is finished, the roles are available as redhat.rhel_system_roles.<role_name>. Additionally, you can find the documentation for each role at /usr/share/ansible/collections/ansible_collections/redhat/rhel_system_roles/roles/<role_name>/README.md.

Verification steps

To verify the installation, run the kernel_settings role with check mode on your local host. However, the kernel_settings role does not work with the --check mode. To make it work, ensure to change the service task and the config task in your playbook to be skipped when in the --check mode. You must also use the --become parameter because it is necessary for the Ansible package module. However, the parameter will not change your system.

  1. Enter the following command:

    $ ansible-playbook -c local -i localhost, --check --become /usr/share/ansible/collections/ansible_collections/redhat/rhel_system_roles/tests/kernel_settings/tests_default.yml

The last line of the command output should contain the value failed=0.

Note

The comma after localhost is mandatory. You must add it even if there is only one host on the list. Without it, ansible-playbook would identify localhost as a file or a directory.

Additional resources

3.4. Installing Collections from Automation Hub

If you are using the Automation Hub, you can install the RHEL System Roles Collection hosted on the Automation Hub.

Prerequisites

  • Access and permissions to one or more managed nodes.
  • Access and permissions to a control node, which is a system from which Red Hat Ansible Core configures other systems.

    On the control node:

    • The ansible-core and rhel-system-roles packages are installed.
    • An inventory file which lists the managed nodes.

Procedure

  1. Define Red Hat Automation Hub as the default source for content in the ansible.cfg configuration file. See Configuring Red Hat Automation Hub as the primary source for content .
  2. Install the redhat.rhel_system_roles collection from the Automation Hub:

    # ansible-galaxy collection install redhat.rhel_system_roles

    After the installation is finished, the roles are available as redhat.rhel_system_roles.<role_name>. Additionally, you can find the documentation for each role at /usr/share/ansible/collections/ansible_collections/redhat/rhel_system_roles/roles/<role_name>/README.md.

Verification steps

To verify the install, run the kernel_settings role with check mode on your localhost. You must also use the --become parameter because it is necessary for the Ansible package module. However, the parameter will not change your system:

  1. Run the following command:

    $ ansible-playbook -c local -i localhost, --check --become /usr/share/ansible/collections/ansible_collections/redhat/rhel_system_roles/tests/kernel_settings/tests_default.yml

The last line of the command output should contain the value failed=0.

Note

The comma after localhost is mandatory. You must add it even if there is only one host on the list. Without it, ansible-playbook would identify localhost as a file or a directory.

Additional resources

3.5. Applying a local logging System Role using Collections

Following is an example using Collections to prepare and apply an Ansible playbook to configure a logging solution on a set of separate machines.

Prerequisites

  • A Collection format of rhel-system-roles is installed either from an rpm package or from the Automation Hub.

Procedure

  1. Create a playbook that defines the required role:

    1. Create a new YAML file and open it in a text editor, for example:

      # vi logging-playbook.yml
    2. Insert the following content into the YAML file:

      ---
      - name: Deploying basics input and implicit files output
        hosts: all
        roles:
          - redhat.rhel_system_roles.logging
        vars:
          logging_inputs:
            - name: system_input
              type: basics
          logging_outputs:
            - name: files_output
              type: files
          logging_flows:
            - name: flow1
              inputs: [system_input]
              outputs: [files_output]
  2. Execute the playbook on a specific inventory:

    # ansible-playbook -i inventory-file logging-playbook.yml

    Where:

    • inventory-file is the name of your inventory file.
    • logging-playbook.yml is the playbook you use.

Verification steps

  1. Test the syntax of the configuration files /etc/rsyslog.conf and /etc/rsyslog.d:

    # rsyslogd -N 1
    rsyslogd: version 8.1911.0-6.el8, config validation run (level 1), master config /etc/rsyslog.conf
    rsyslogd: End of config validation run. Bye.
  2. Verify that the system sends messages to the log:

    1. Send a test message:

      # logger test
    2. View the /var/log/messages log, for example:

      # cat /var/log/messages
      Aug  5 13:48:31 hostname root[6778]: test

      The hostname is the hostname of the client system. The log displays the user name of the user that entered the logger command, in this case, root.

Chapter 4. Ansible IPMI modules in RHEL

4.1. The rhel_mgmt collection

The Intelligent Platform Management Interface (IPMI) is a specification for a set of standard protocols to communicate with baseboard management controller (BMC) devices. The IPMI modules allow you to enable and support hardware management automation. The IPMI modules are available in:

  • The rhel_mgmt Collection. The package name is ansible-collection-redhat-rhel_mgmt.
  • The RHEL 8 AppStream, as part of the new ansible-collection-redhat-rhel_mgmt package.

The following IPMI modules are available in the rhel_mgmt collection:

  • ipmi_boot: Management of boot device order
  • ipmi_power: Power management for machine

The mandatory parameters used for the IPMI Modules are:

  • ipmi_boot parameters:
Module nameDescription

name

Hostname or ip address of the BMC

password

Password to connect to the BMC

bootdev

Device to be used on next boot

* network

* floppy

* hd

* safe

* optical

* setup

* default

User

Username to connect to the BMC

  • ipmi_power parameters:
Module nameDescription

name

BMC Hostname or IP address

password

Password to connect to the BMC

user

Username to connect to the BMC

State

Check if the machine is on the desired status

* on

* off

* shutdown

* reset

* boot

4.2. Installing the rhel mgmt Collection using the CLI

You can install the rhel_mgmt Collection using the command line.

Prerequisites

  • The ansible-core package is installed.

Procedure

  • Install the collection via RPM package:

    # yum install ansible-collection-redhat-rhel_mgmt

    After the installation is finished, the IPMI modules are available in the redhat.rhel_mgmt Ansible collection.

Additional resources

  • The ansible-playbook man page.

4.3. Example using the ipmi_boot module

The following example shows how to use the ipmi_boot module in a playbook to set a boot device for the next boot. For simplicity, the examples use the same host as the Ansible control host and managed host, thus executing the modules on the same host where the playbook is executed.

Prerequisites

  • The rhel_mgmt collection is installed.
  • The pyghmi library in the python3-pyghmi package is installed in one of the following locations:

    • The host where you execute the playbook.
    • The managed host. If you use localhost as the managed host, install the python3-pyghmi package on the host where you execute the playbook instead.
  • The IPMI BMC that you want to control is accessible via network from the host where you execute the playbook, or the managed host (if not using localhost as the managed host). Note that the host whose BMC is being configured by the module is generally different from the host where the module is executing (the Ansible managed host), as the module contacts the BMC over the network using the IPMI protocol.
  • You have credentials to access BMC with an appropriate level of access.

Procedure

  1. Create a new playbook.yml file with the following content:

    ---
    - name: Sets which boot device will be used on next boot
      hosts: localhost
        tasks:
        - redhat.rhel_mgmt.ipmi_boot:
           name: bmc.host.example.com
             user: admin_user
             password: basics
             bootdev: hd
  2. Execute the playbook against localhost:

    # ansible-playbook playbook.yml

As a result, the output returns the value “success”.

4.4. Example using the ipmi_power module

This example shows how to use the ipmi_boot module in a playbook to check if the system is turned on. For simplicity, the examples use the same host as the Ansible control host and managed host, thus executing the modules on the same host where the playbook is executed.

Prerequisites

  • The rhel_mgmt collection is installed.
  • The pyghmi library in the python3-pyghmi package is installed in one of the following locations:

    • The host where you execute the playbook.
    • The managed host. If you use localhost as the managed host, install the python3-pyghmi package on the host where you execute the playbook instead.
  • The IPMI BMC that you want to control is accessible via network from the host where you execute the playbook, or the managed host (if not using localhost as the managed host). Note that the host whose BMC is being configured by the module is generally different from the host where the module is executing (the Ansible managed host), as the module contacts the BMC over the network using the IPMI protocol.
  • You have credentials to access BMC with an appropriate level of access.

Procedure

  1. Create a new playbook.yml file with the following content:

    ---
    - name: Turn the host on
      hosts: localhost
        tasks:
        - redhat.rhel_mgmt.ipmi_power:
           name: bmc.host.example.com
             user: admin_user
             password: basics
             state: on
  2. Execute the playbook:

    # ansible-playbook playbook.yml

The output returns the value “true”.

Chapter 5. The Redfish modules in RHEL

The Redfish modules for remote management of devices are now part of the redhat.rhel_mgmt Ansible collection. With the Redfish modules, you can easily use management automation on bare-metal servers and platform hardware by getting information about the servers or control them through an Out-Of-Band (OOB) controller, using the standard HTTPS transport and JSON format.

5.1. The Redfish modules

The redhat.rhel_mgmt Ansible collection provides the Redfish modules to support hardware management in Ansible over Redfish. The redhat.rhel_mgmt collection is available in the ansible-collection-redhat-rhel_mgmt package. To install it, see Installing the redhat.rhel_mgmt Collection using the CLI.

The following Redfish modules are available in the redhat.rhel_mgmt collection:

  1. redfish_info: The redfish_info module retrieves information about the remote Out-Of-Band (OOB) controller such as systems inventory.
  2. redfish_command: The redfish_command module performs Out-Of-Band (OOB) controller operations like log management and user management, and power operations such as system restart, power on and off.
  3. redfish_config: The redfish_config module performs OOB controller operations such as changing OOB configuration, or setting the BIOS configuration.

5.2. Redfish modules parameters

The parameters used for the Redfish modules are:

redfish_info parameters:Description

baseuri

(Mandatory) - Base URI of OOB controller.

category

(Mandatory) - List of categories to execute on OOB controller. The default value is ["Systems"].

command

(Mandatory) - List of commands to execute on OOB controller.

username

Username for authentication to OOB controller.

password

Password for authentication to OOB controller.

redfish_command parameters:Description

baseuri

(Mandatory) - Base URI of OOB controller.

category

(Mandatory) - List of categories to execute on OOB controller. The default value is ["Systems"].

command

(Mandatory) - List of commands to execute on OOB controller.

username

Username for authentication to OOB controller.

password

Password for authentication to OOB controller.

redfish_config parameters:Description

baseuri

(Mandatory) - Base URI of OOB controller.

category

(Mandatory) - List of categories to execute on OOB controller. The default value is ["Systems"].

command

(Mandatory) - List of commands to execute on OOB controller.

username

Username for authentication to OOB controller.

password

Password for authentication to OOB controller.

bios_attributes

BIOS attributes to update.

5.3. Using the redfish_info module

The following example shows how to use the redfish_info module in a playbook to get information about the CPU inventory. For simplicity, the example uses the same host as the Ansible control host and managed host, thus executing the modules on the same host where the playbook is executed.

Prerequisites

  • The redhat.rhel_mgmt collection is installed.
  • The pyghmi library in the python3-pyghmi package is installed on the managed host. If you use localhost as the managed host, install the python3-pyghmi package on the host where you execute the playbook.
  • OOB controller access details.

Procedure

  1. Create a new playbook.yml file with the following content:

    ---
    - name: Get CPU inventory
      hosts: localhost
      tasks:
        - redhat.rhel_mgmt.redfish_info:
            baseuri: "{{ baseuri }}"
            username: "{{ username }}"
            password: "{{ password }}"
            category: Systems
            command: GetCpuInventory
          register: result
  2. Execute the playbook against localhost:

    # ansible-playbook playbook.yml

As a result, the output returns the CPU inventory details.

5.4. Using the redfish_command module

The following example shows how to use the redfish_command module in a playbook to turn on a system. For simplicity, the example uses the same host as the Ansible control host and managed host, thus executing the modules on the same host where the playbook is executed.

Prerequisites

  • The redhat.rhel_mgmt collection is installed.
  • The pyghmi library in the python3-pyghmi package is installed on the managed host. If you use localhost as the managed host, install the python3-pyghmi package on the host where you execute the playbook.
  • OOB controller access details.

Procedure

  1. Create a new playbook.yml file with the following content:

    ---
    - name: Power on system
      hosts: localhost
      tasks:
        - redhat.rhel_mgmt.redfish_command:
            baseuri: "{{ baseuri }}"
            username: "{{ username }}"
            password: "{{ password }}"
            category: Systems
            command: PowerOn
  2. Execute the playbook against localhost:

    # ansible-playbook playbook.yml

As a result, the system powers on.

5.5. Using the redfish_config module

The following example shows how to use the redfish_config module in a playbook to configure a system to boot with UEFI. For simplicity, the example uses the same host as the Ansible control host and managed host, thus executing the modules on the same host where the playbook is executed.

Prerequisites

  • The redhat.rhel_mgmt collection is installed.
  • The pyghmi library in the python3-pyghmi package is installed on the managed host. If you use localhost as the managed host, install the python3-pyghmi package on the host where you execute the playbook.
  • OOB controller access details.

Procedure

  1. Create a new playbook.yml file with the following content:

    ---
    - name: "Set BootMode to UEFI"
      hosts: localhost
      tasks:
        - redhat.rhel_mgmt.redfish_config:
            baseuri: "{{ baseuri }}"
            username: "{{ username }}"
            password: "{{ password }}"
            category: Systems
            command: SetBiosAttributes
            bios_attributes:
              BootMode: Uefi
  2. Execute the playbook against localhost:

    # ansible-playbook playbook.yml

As a result, the system boot mode is set to UEFI.

Chapter 6. Configuring kernel parameters permanently by using the kernel_settings RHEL System Role

As an experienced user with good knowledge of Red Hat Ansible, you can use the kernel_settings role to configure kernel parameters on multiple clients at once. This solution:

  • Provides a friendly interface with efficient input setting.
  • Keeps all intended kernel parameters in one place.

After you run the kernel_settings role from the control machine, the kernel parameters are applied to the managed systems immediately and persist across reboots.

Important

Note that RHEL System Role delivered over RHEL channels are available to RHEL customers as an RPM package in the default AppStream repository. RHEL System Role are also available as a collection to customers with Ansible subscriptions over Ansible Automation Hub.

6.1. Introduction to the kernel_settings role

RHEL System Roles is a set of roles that provide a consistent configuration interface to remotely manage multiple systems.

RHEL System Roles were introduced for automated configurations of the kernel using the kernel_settings System Role. The rhel-system-roles package contains this system role, and also the reference documentation.

To apply the kernel parameters on one or more systems in an automated fashion, use the kernel_settings role with one or more of its role variables of your choice in a playbook. A playbook is a list of one or more plays that are human-readable, and are written in the YAML format.

You can use an inventory file to define a set of systems that you want Ansible to configure according to the playbook.

With the kernel_settings role you can configure:

  • The kernel parameters using the kernel_settings_sysctl role variable
  • Various kernel subsystems, hardware devices, and device drivers using the kernel_settings_sysfs role variable
  • The CPU affinity for the systemd service manager and processes it forks using the kernel_settings_systemd_cpu_affinity role variable
  • The kernel memory subsystem transparent hugepages using the kernel_settings_transparent_hugepages and kernel_settings_transparent_hugepages_defrag role variables

Additional resources

6.2. Applying selected kernel parameters using the kernel_settings role

Follow these steps to prepare and apply an Ansible playbook to remotely configure kernel parameters with persisting effect on multiple managed operating systems.

Prerequisites

  • You have root permissions.
  • Entitled by your RHEL subscription, you installed the ansible-core and rhel-system-roles packages on the control machine.
  • An inventory of managed hosts is present on the control machine and Ansible is able to connect to them.
Important

RHEL 8.0 - 8.5 provided access to a separate Ansible repository that contains Ansible Engine 2.9 for automation based on Ansible. Ansible Engine contains command-line utilities such as ansible, ansible-playbook; connectors such as docker and podman; and the entire world of plugins and modules. For information about how to obtain and install Ansible Engine, refer to How do I Download and Install Red Hat Ansible Engine?.

RHEL 8.6 and 9.0 has introduced Ansible Core (provided as ansible-core RPM), which contains the Ansible command-line utilities, commands, and a small set of built-in Ansible plugins. The AppStream repository provides ansible-core, which has a limited scope of support. You can learn more by reviewing Scope of support for the ansible-core package included in the RHEL 9 AppStream.

Procedure

  1. Optionally, review the inventory file for illustration purposes:

    #  cat /home/jdoe/<ansible_project_name>/inventory
    [testingservers]
    pdoe@192.168.122.98
    fdoe@192.168.122.226
    
    [db-servers]
    db1.example.com
    db2.example.com
    
    [webservers]
    web1.example.com
    web2.example.com
    192.0.2.42

    The file defines the [testingservers] group and other groups. It allows you to run Ansible more effectively against a specific set of systems.

  2. Create a configuration file to set defaults and privilege escalation for Ansible operations.

    1. Create a new YAML file and open it in a text editor, for example:

      #  vi /home/jdoe/<ansible_project_name>/ansible.cfg
    2. Insert the following content into the file:

      [defaults]
      inventory = ./inventory
      
      [privilege_escalation]
      become = true
      become_method = sudo
      become_user = root
      become_ask_pass = true

      The [defaults] section specifies a path to the inventory file of managed hosts. The [privilege_escalation] section defines that user privileges be shifted to root on the specified managed hosts. This is necessary for successful configuration of kernel parameters. When Ansible playbook is run, you will be prompted for user password. The user automatically switches to root by means of sudo after connecting to a managed host.

  3. Create an Ansible playbook that uses the kernel_settings role.

    1. Create a new YAML file and open it in a text editor, for example:

      #  vi /home/jdoe/<ansible_project_name>/kernel-roles.yml

      This file represents a playbook and usually contains an ordered list of tasks, also called plays, that are run against specific managed hosts selected from your inventory file.

    2. Insert the following content into the file:

      ---
      -
        hosts: testingservers
        name: "Configure kernel settings"
        roles:
          - rhel-system-roles.kernel_settings
        vars:
          kernel_settings_sysctl:
            - name: fs.file-max
              value: 400000
            - name: kernel.threads-max
              value: 65536
          kernel_settings_sysfs:
            - name: /sys/class/net/lo/mtu
              value: 65000
          kernel_settings_transparent_hugepages: madvise

      The name key is optional. It associates an arbitrary string with the play as a label and identifies what the play is for. The hosts key in the play specifies the hosts against which the play is run. The value or values for this key can be provided as individual names of managed hosts or as groups of hosts as defined in the inventory file.

      The vars section represents a list of variables containing selected kernel parameter names and values to which they have to be set.

      The roles key specifies what system role is going to configure the parameters and values mentioned in the vars section.

      Note

      You can modify the kernel parameters and their values in the playbook to fit your needs.

  4. Optionally, verify that the syntax in your play is correct.

    #  ansible-playbook --syntax-check kernel-roles.yml
    
    playbook: kernel-roles.yml

    This example shows the successful verification of a playbook.

  5. Execute your playbook.

    #  ansible-playbook kernel-roles.yml
    
    ...
    
    BECOME password:
    
    PLAY [Configure kernel settings] **********************************************************************************
    
    
    
    PLAY RECAP ********************************************************************************************************
    fdoe@192.168.122.226       : ok=10   changed=4    unreachable=0    failed=0    skipped=6    rescued=0    ignored=0
    pdoe@192.168.122.98        : ok=10   changed=4    unreachable=0    failed=0    skipped=6    rescued=0    ignored=0

    Before Ansible runs your playbook, you are going to be prompted for your password and so that a user on managed hosts can be switched to root, which is necessary for configuring kernel parameters.

    The recap section shows that the play finished successfully (failed=0) for all managed hosts, and that 4 kernel parameters have been applied (changed=4).

  6. Restart your managed hosts and check the affected kernel parameters to verify that the changes have been applied and persist across reboots.

Additional resources

Chapter 7. Using the rhc System Role to register the system

The rhc RHEL System Role enables administrators to automate the registration of multiple systems with Red Hat Subscription Management (RHSM) and Satellite servers. The role also supports Insights-related configuration and management tasks by using Ansible.

7.1. Introduction to the rhc System Role

RHEL System Role is a set of roles that provides a consistent configuration interface to remotely manage multiple systems. The remote host configuration (rhc) System Role enables administrators to easily register RHEL systems to Red Hat Subscription Management (RHSM) and Satellite servers. By default, when you register a system by using the rhc System Role, the system is connected to Insights. Additionally, with the rhc System Role, you can:

  • Configure connections to Red Hat Insights
  • Enable and disable repositories
  • Configure the proxy to use for the connection
  • Configure insights remediations and, auto updates
  • Set the release of the system
  • Configure insights tags

7.2. Registering a system by using the rhc System Role

You can register your system to Red Hat by using the rhc RHEL System Role. By default, the rhc RHEL System Role connects the system to Red Hat Insights when you register it.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The managed nodes or groups of managed nodes on which you want to run this playbook are listed in the Ansible inventory file.

Procedure

  1. Create a vault to save the sensitive information:

    $ ansible-vault create secrets.yml
    New Vault password: password
    Confirm New Vault password: password
  2. The ansible-vault create command creates an encrypted vault file and opens it in an editor. Enter the sensitive data you want to save in the vault, for example:

    activationKey: activation_key
    username: username
    password: password
  3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

    You can later edit the data in the vault by using the ansible-vault edit secrets.yml command.

  4. Optional: Display the vault content:

    $ ansible-vault view secrets.yml
  5. Create a playbook file, for example ~/registration.yml, and use one of the following options depending on the action you want to perform:

    1. To register by using an activation key and organization ID (recommended), use the following playbook:

      ---
      - name: Registering system using activation key and organization ID
        hosts: managed-node-01.example.com
        vars_files:
          - secrets.yml
        vars:
          rhc_auth:
            activation_keys:
              keys:
                -  "{{ activationKey }}"
          rhc_organization: organizationID
        roles:
          - role: rhel-system-roles.rhc
    2. To register by using a username and password, use the following playbook:

      ---
      - name: Registering system with username and password
        hosts:  managed-node-01.example.com
        vars_files:
          - secrets.yml
        vars:
          rhc_auth:
            login:
              username: "{{ username }}"
              password: "{{ password }}"
        roles:
          - role: rhel-system-roles.rhc
  6. Run the playbook:

    # ansible-playbook ~/registration.yml --ask-vault-pass

Additional resources

  • The /usr/share/ansible/roles/rhel-system-roles.rhc/README.md file

7.3. Registering a system with Satellite by using the rhc System Role

When organizations use Satellite to manage systems, it is necessary to register the system through Satellite. You can remotely register your system with Satellite by using the rhc RHEL System Role.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The managed nodes or groups of managed nodes on which you want to run this playbook are listed in the Ansible inventory file.

Procedure

  1. Create a vault to save the sensitive information:

    $ ansible-vault create secrets.yml
    New Vault password: password
    Confirm New Vault password: password
  2. The ansible-vault create command creates an encrypted file and opens it in an editor. Enter the sensitive data you want to save in the vault, for example:

    activationKey: activation_key
  3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

    You can later edit the data in the vault by using the ansible-vault edit secrets.yml command.

  4. Optional: Display the vault content:

    $ ansible-vault view secrets.yml
  5. Create a playbook file, for example ~/registration-sat.yml.
  6. Use the following text in ~/registration-sat.yml to register the system by using an activation key and organization ID:

    ---
    - name: Register to the custom registration server and CDN
      hosts: managed-node-01.example.com
      vars_files:
        - secrets.yml
      vars:
        rhc_auth:
          login:
            activation_keys:
              keys:
                - "{{ activationKey }}"
            rhc_organization: organizationID
        rhc_server:
          hostname: example.com
            port: 443
            prefix: /rhsm
        rhc_baseurl: http://example.com/pulp/content
       roles:
         - role: rhel-system-roles.rhc
  7. Run the playbook:

    # ansible-playbook ~/registration-sat.yml --ask-vault-pass

Additional resources

  • The /usr/share/ansible/roles/rhel-system-roles.rhc/README.md file

7.4. Disabling the connection to Insights after the registration by using the rhc System Role

When you register a system by using the rhc RHEL System Role, the role by default, enables the connection to Red Hat Insights. You can disable it by using the rhc System Role, if not required.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The managed nodes or groups of managed nodes on which you want to run this playbook are listed in the Ansible inventory file.
  • The system is already registered.

Procedure

  1. Create a playbook file, for example ~/dis-insights.yml and add the following content in it:

    ---
    - name: Disable Insights connection
      hosts: managed-node-01.example.com
      vars:
        rhc_insights:
          state: absent
      roles:
        - role: rhel-system-roles.rhc
  2. Run the playbook:

    # ansible-playbook ~/dis-insights.yml

Additional resources

  • The /usr/share/ansible/roles/rhel-system-roles.rhc/README.md file

7.5. Enabling repositories by using the rhc System Role

You can remotely enable or disable repositories on managed nodes by using the rhc RHEL System Role.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The managed nodes or groups of managed nodes on which you want to run this playbook are listed in the Ansible inventory file.
  • You have details of the repositories which you want to enable or disable on the managed nodes.
  • You have registered the system.

Procedure

  1. Create a playbook file, for example ~/configure-repos.yml:

    1. To enable a repository:

      ---
      - name: Enable repository
        hosts: managed-node-01.example.com
        vars:
          rhc_repositories:
            - {name: "RepositoryName", state: enabled}
         roles:
           - role: rhel-system-roles.rhc
    2. To disable a repository:

      ---
      - name: Disable repository
        hosts: managed-node-01.example.com
        vars:
          rhc_repositories:
            - {name: "RepositoryName", state: disabled}
         roles:
           - role: rhel-system-roles.rhc
  2. Run the playbook:

    # ansible-playbook ~/configure-repos.yml

Additional resources

  • The /usr/share/ansible/roles/rhel-system-roles.rhc/README.md file

7.6. Setting release versions by using the rhc system role

You can limit the system to use only repositories for a particular minor RHEL version instead of the latest one. This way, you can lock your system to a specific minor RHEL version.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The managed nodes or groups of managed nodes on which you want to run this playbook are listed in the Ansible inventory file.
  • You know the minor RHEL version to which you want to lock the system. Note that you can only lock the system to the RHEL minor version that the host currently runs or a later minor version.
  • You have registered the system.

Procedure

  1. Create a playbook file, for example ~/release.yml:

    ---
    - name: Set Release
      hosts: managed-node-01.example.com
      vars:
        rhc_release: "8.6"
      roles:
        - role: rhel-system-roles.rhc
  2. Run the playbook:

    # ansible-playbook ~/release.yml

Additional resources

  • The /usr/share/ansible/roles/rhel-system-roles.rhc/README.md file

7.7. Using a proxy server when registering the host by using the rhc System Role

If your security restrictions allow access to the Internet only through a proxy server, you can specify the proxy’s settings in the playbook when you register the system using the rhc RHEL System Role.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The managed nodes or groups of managed nodes on which you want to run this playbook are listed in the Ansible inventory file.

Procedure

  1. Create a vault to save the sensitive information:

    $ ansible-vault create secrets.yml
    New Vault password: password
    Confirm New Vault password: password
  2. The ansible-vault create command creates an encrypted file and opens it in an editor. Enter the sensitive data you want to save in the vault, for example:

    username: username
    password: password
    proxy_username: proxyusernme
    proxy_password: proxypassword
  3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

    You can later edit the data in the vault by using the ansible-vault edit secrets.yml command.

  4. Optional: Display the vault content:

    $ ansible-vault view secrets.yml
  5. Create a playbook file, for example ~/configure-proxy.yml:

    1. To register to the RHEL customer portal by using a proxy:

      ---
      - name: Register using proxy
        hosts: managed-node-01.example.com
        vars_files:
          - secrets.yml
        vars:
          rhc_auth:
            login:
              username: "{{ username }}"
              password: "{{ password }}"
          rhc_proxy:
            hostname: proxy.example.com
            port: 3128
            username: "{{ proxy_username }}"
            password: "{{ proxy_password }}"
        roles:
          - role: rhel-system-roles.rhc
    2. To remove the proxy server from the configuration of the Red Hat Subscription Manager service:

      ---
      - name: To stop using proxy server for registration
        hosts: managed-node-01.example.com
        vars_files:
          - secrets.yml
        vars:
          rhc_auth:
            login:
              username: "{{ username }}"
              password: "{{ password }}"
           rhc_proxy: {"state":"absent"}
        roles:
          - role: rhel-system-roles.rhc
  6. Run the playbook:

    # ansible-playbook ~/configure-proxy.yml --ask-vault-pass

Additional resources

  • The /usr/share/ansible/roles/rhel-system-roles.rhc/README.md file

7.8. Disabling auto updates of Insights rules by using the rhc System Role

You can disable the automatic collection rule updates for Red Hat Insights by using the rhc RHEL System Role. By default, when you connect your system to Red Hat Insights, this option is enabled. You can disable it by using the rhc RHEL System Role.

Note

If you disable this feature, you risk using outdated rule definition files and not getting the most recent validation updates.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The managed nodes or groups of managed nodes on which you want to run this playbook are listed in the Ansible inventory file.
  • You have registered the system.

Procedure

  1. Create a vault to save the sensitive information:

    $ ansible-vault create secrets.yml
    New Vault password: password
    Confirm New Vault password: password
  2. The ansible-vault create command creates an encrypted file and opens it in an editor. Enter the sensitive data you want to save in the vault, for example:

    username: username
    password: password
  3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

    You can later edit the data in the vault by using the ansible-vault edit secrets.yml command.

  4. Optional: Display the vault content:

    $ ansible-vault view secrets.yml
  5. Create a playbook file, for example ~/auto-update.yml and add following content to it:

    ---
     - name: Disable Red Hat Insights autoupdates
       hosts: managed-node-01.example.com
       vars_files:
         - secrets.yml
       vars:
        rhc_auth:
          login:
            username: "{{ username }}"
            password: "{{ password }}"
        rhc_insights:
           autoupdate: false
           state: present
        roles:
          - role: rhel-system-roles.rhc
  6. Run the playbook:

    # ansible-playbook ~/auto-update.yml --ask-vault-pass

Additional resources

  • The /usr/share/ansible/roles/rhel-system-roles.rhc/README.md file

7.9. Disabling Insights remediations by using the rhc RHEL System Role

You can configure systems to automatically update the dynamic configuration by using the rhc RHEL System Role. When you connect your system to Red hat Insights, it is enabled by default. You can disable it, if not required.

Note

Enabling remediation with the rhc System Role ensures your system is ready to be remediated when connected directly to Red Hat. For systems connected to a Satellite, or Capsule, enabling remediation must be achieved differently. For more information about Red Hat Insights remediations, see Red Hat Insights Remediations Guide.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The managed nodes or groups of managed nodes on which you want to run this playbook are listed in the Ansible inventory file.
  • You have Insights remediations enabled.
  • You have registered the system.

Procedure

  1. To enable the remediation, create a playbook file, for example ~/remediation.yml:

    ---
    - name: Disable remediation
      hosts: managed-node-01.example.com
      vars:
        rhc_insights:
          remediation: absent
          state: present
      roles:
        - role: rhel-system-roles.rhc
  2. Run the playbook:

    # ansible-playbook ~/remediation.yml

Additional resources

  • The /usr/share/ansible/roles/rhel-system-roles.rhc/README.md file

7.10. Configuring Insights tags by using the rhc system role

You can use tags for system filtering and grouping. You can also customize tags based on the requirements.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The managed nodes or groups of managed nodes on which you want to run this playbook are listed in the Ansible inventory file.

Procedure

  1. Create a vault to save the sensitive information:

    $ ansible-vault create secrets.yml
    New Vault password: password
    Confirm New Vault password: password
  2. The ansible-vault create command creates an encrypted file and opens it in an editor. Enter the sensitive data you want to save in the vault, for example:

    username: username
    password: password
  3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

    You can later edit the data in the vault by using the ansible-vault edit secrets.yml command.

  4. Optional: Display the vault content:

    $ ansible-vault view secrets.yml
  5. Create a playbook file, for example ~/tags.yml, and add following content to it:

    ---
    - name: Creating tags
      hosts: managed-node-01.example.com
      vars_files:
        - secrets.yml
      vars:
        rhc_auth:
          login:
            username: "{{ username }}"
            password: "{{ password }}"
        rhc_insights:
          tags:
            group: group-name-value
              location: location-name-value
              description:
                - RHEL8
                - SAP
               sample_key:value
            state: present
      roles:
        - role: rhel-system-roles.rhc
  6. Run the playbook:

    # ansible-playbook ~/remediation.yml --ask-vault-pass

Additional resources

7.11. Unregistering a system by using the RHC System Role

You can unregister the system from Red Hat if you no longer need the subscription service.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The managed nodes or groups of managed nodes on which you want to run this playbook are listed in the Ansible inventory file.
  • The system is already registered.

Procedure

  1. To unregister, create a playbook file, for example, ~/unregister.yml and add the following content to it:

    ---
    - name: Unregister the system
      hosts: managed-node-01.example.com
      vars:
        rhc_state: absent
      roles:
        - role: rhel-system-roles.rhc
  2. Run the playbook:

    # ansible-playbook ~/unregister.yml

Additional resources

  • The /usr/share/ansible/roles/rhel-system-roles.rhc/README.md file

Chapter 8. Configuring network settings by using RHEL System Roles

Administrators can automate network-related configuration and management tasks by using the network RHEL System Role.

8.1. Configuring an Ethernet connection with a static IP address by using the network RHEL System Role with an interface name

You can remotely configure an Ethernet connection by using the network RHEL System Role.

Perform this procedure on the Ansible control node.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The managed nodes or groups of managed nodes on which you want to run this playbook are listed in the Ansible inventory file.
  • A physical or virtual Ethernet device exists in the server’s configuration.
  • The managed nodes use NetworkManager to configure the network.

Procedure

  1. Create a playbook file, for example ~/ethernet-static-IP.yml, with the following content:

    ---
    - name: Configure the network
      hosts: managed-node-01.example.com
      tasks:
      - name: Configure an Ethernet connection with static IP
        include_role:
          name: rhel-system-roles.network
    
        vars:
          network_connections:
            - name: enp1s0
              interface_name: enp1s0
              type: ethernet
              autoconnect: yes
              ip:
                address:
                  - 192.0.2.1/24
                  - 2001:db8:1::1/64
                gateway4: 192.0.2.254
                gateway6: 2001:db8:1::fffe
                dns:
                  - 192.0.2.200
                  - 2001:db8:1::ffbb
                dns_search:
                  - example.com
              state: up

    These settings define an Ethernet connection profile for the enp1s0 device with the following settings:

    • A static IPv4 address - 192.0.2.1 with a /24 subnet mask
    • A static IPv6 address - 2001:db8:1::1 with a /64 subnet mask
    • An IPv4 default gateway - 192.0.2.254
    • An IPv6 default gateway - 2001:db8:1::fffe
    • An IPv4 DNS server - 192.0.2.200
    • An IPv6 DNS server - 2001:db8:1::ffbb
    • A DNS search domain - example.com
  2. Validate the playbook syntax:

    # ansible-playbook ~/ethernet-static-IP.yml --syntax-check

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook:

    # ansible-playbook ~/ethernet-static-IP.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.network/README.md file

8.2. Configuring an Ethernet connection with a static IP address by using the network RHEL System Role with a device path

You can remotely configure an Ethernet connection using the network RHEL System Role.

You can identify the device path with the following command:

# udevadm info /sys/class/net/<device_name> | grep ID_PATH=

Perform this procedure on the Ansible control node.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The managed nodes or groups of managed nodes on which you want to run this playbook are listed in the Ansible inventory file.
  • A physical or virtual Ethernet device exists in the server’s configuration.
  • The managed nodes use NetworkManager to configure the network.

Procedure

  1. Create a playbook file, for example ~/ethernet-static-IP.yml, with the following content:

    ---
    - name: Configure the network
      hosts: managed-node-01.example.com
      tasks:
      - name: Configure an Ethernet connection with static IP
        include_role:
          name: rhel-system-roles.network
    
        vars:
          network_connections:
            - name: example
              match:
                path:
                  - pci-0000:00:0[1-3].0
                  - &!pci-0000:00:02.0
              type: ethernet
              autoconnect: yes
              ip:
                address:
                  - 192.0.2.1/24
                  - 2001:db8:1::1/64
                gateway4: 192.0.2.254
                gateway6: 2001:db8:1::fffe
                dns:
                  - 192.0.2.200
                  - 2001:db8:1::ffbb
                dns_search:
                  - example.com
              state: up

    These settings define an Ethernet connection profile with the following settings:

    • A static IPv4 address - 192.0.2.1 with a /24 subnet mask
    • A static IPv6 address - 2001:db8:1::1 with a /64 subnet mask
    • An IPv4 default gateway - 192.0.2.254
    • An IPv6 default gateway - 2001:db8:1::fffe
    • An IPv4 DNS server - 192.0.2.200
    • An IPv6 DNS server - 2001:db8:1::ffbb
    • A DNS search domain - example.com

    The match parameter in this example defines that Ansible applies the play to devices that match PCI ID 0000:00:0[1-3].0, but not 0000:00:02.0. For further details about special modifiers and wild cards you can use, see the match parameter description in the /usr/share/ansible/roles/rhel-system-roles.network/README.md file.

  2. Validate the playbook syntax:

    # ansible-playbook ~/ethernet-static-IP.yml --syntax-check

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook:

    # ansible-playbook ~/ethernet-static-IP.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.network/README.md file

8.3. Configuring an Ethernet connection with a dynamic IP address by using the network RHEL System Role with an interface name

You can remotely configure an Ethernet connection using the network RHEL System Role. For connections with dynamic IP address settings, NetworkManager requests the IP settings for the connection from a DHCP server.

Perform this procedure on the Ansible control node.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The managed nodes or groups of managed nodes on which you want to run this playbook are listed in the Ansible inventory file.
  • A physical or virtual Ethernet device exists in the server’s configuration.
  • A DHCP server is available in the network
  • The managed nodes use NetworkManager to configure the network.

Procedure

  1. Create a playbook file, for example ~/ethernet-dynamic-IP.yml, with the following content:

    ---
    - name: Configure the network
      hosts: managed-node-01.example.com
      tasks:
      - name: Configure an Ethernet connection with dynamic IP
        include_role:
          name: rhel-system-roles.network
    
        vars:
          network_connections:
            - name: enp1s0
              interface_name: enp1s0
              type: ethernet
              autoconnect: yes
              ip:
                dhcp4: yes
                auto6: yes
              state: up

    These settings define an Ethernet connection profile for the enp1s0 device. The connection retrieves IPv4 addresses, IPv6 addresses, default gateway, routes, DNS servers, and search domains from a DHCP server and IPv6 stateless address autoconfiguration (SLAAC).

  2. Validate the playbook syntax:

    # ansible-playbook ~/ethernet-dynamic-IP.yml --syntax-check

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook:

    # ansible-playbook ~/ethernet-dynamic-IP.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.network/README.md file

8.4. Configuring an Ethernet connection with a dynamic IP address by using the network RHEL System Role with a device path

You can remotely configure an Ethernet connection using the network RHEL System Role. For connections with dynamic IP address settings, NetworkManager requests the IP settings for the connection from a DHCP server.

You can identify the device path with the following command:

# udevadm info /sys/class/net/<device_name> | grep ID_PATH=

Perform this procedure on the Ansible control node.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The managed nodes or groups of managed nodes on which you want to run this playbook are listed in the Ansible inventory file.
  • A physical or virtual Ethernet device exists in the server’s configuration.
  • A DHCP server is available in the network.
  • The managed hosts use NetworkManager to configure the network.

Procedure

  1. Create a playbook file, for example ~/ethernet-dynamic-IP.yml, with the following content:

    ---
    - name: Configure the network
      hosts: managed-node-01.example.com
      tasks:
      - name: Configure an Ethernet connection with dynamic IP
        include_role:
          name: rhel-system-roles.network
    
        vars:
          network_connections:
            - name: example
              match:
                path:
                  - pci-0000:00:0[1-3].0
                  - &!pci-0000:00:02.0
              type: ethernet
              autoconnect: yes
              ip:
                dhcp4: yes
                auto6: yes
              state: up

    These settings define an Ethernet connection profile. The connection retrieves IPv4 addresses, IPv6 addresses, default gateway, routes, DNS servers, and search domains from a DHCP server and IPv6 stateless address autoconfiguration (SLAAC).

    The match parameter in this example defines that Ansible applies the play to devices that match PCI ID 0000:00:0[1-3].0, but not 0000:00:02.0. For further details about special modifiers and wild cards you can use, see the match parameter description in the /usr/share/ansible/roles/rhel-system-roles.network/README.md file.

  2. Validate the playbook syntax:

    # ansible-playbook ~/ethernet-dynamic-IP.yml --syntax-check

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook:

    # ansible-playbook ~/ethernet-dynamic-IP.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.network/README.md file

8.5. Configuring VLAN tagging by using the network RHEL System Role

You can use the network RHEL System Role to configure VLAN tagging. This example adds an Ethernet connection and a VLAN with ID 10 on top of this Ethernet connection. As the child device, the VLAN connection contains the IP, default gateway, and DNS configurations.

Depending on your environment, adjust the play accordingly. For example:

  • To use the VLAN as a port in other connections, such as a bond, omit the ip attribute, and set the IP configuration in the child configuration.
  • To use team, bridge, or bond devices in the VLAN, adapt the interface_name and type attributes of the ports you use in the VLAN.

Perform this procedure on the Ansible control node.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The managed nodes or groups of managed nodes on which you want to run this playbook are listed in the Ansible inventory file.

Procedure

  1. Create a playbook file, for example ~/vlan-ethernet.yml, with the following content:

    ---
    - name: Configure the network
      hosts: managed-node-01.example.com
      tasks:
      - name: Configure a VLAN that uses an Ethernet connection
        include_role:
          name: rhel-system-roles.network
    
        vars:
          network_connections:
            # Add an Ethernet profile for the underlying device of the VLAN
            - name: enp1s0
              type: ethernet
              interface_name: enp1s0
              autoconnect: yes
              state: up
              ip:
                dhcp4: no
                auto6: no
    
            # Define the VLAN profile
            - name: enp1s0.10
              type: vlan
              ip:
                address:
                  - "192.0.2.1/24"
                  - "2001:db8:1::1/64"
                gateway4: 192.0.2.254
                gateway6: 2001:db8:1::fffe
                dns:
                  - 192.0.2.200
                  - 2001:db8:1::ffbb
                dns_search:
                  - example.com
              vlan_id: 10
              parent: enp1s0
              state: up

    These settings define a VLAN to operate on top of the enp1s0 device. The VLAN interface has the following settings:

    • A static IPv4 address - 192.0.2.1 with a /24 subnet mask
    • A static IPv6 address - 2001:db8:1::1 with a /64 subnet mask
    • An IPv4 default gateway - 192.0.2.254
    • An IPv6 default gateway - 2001:db8:1::fffe
    • An IPv4 DNS server - 192.0.2.200
    • An IPv6 DNS server - 2001:db8:1::ffbb
    • A DNS search domain - example.com
    • VLAN ID - 10

    The parent attribute in the VLAN profile configures the VLAN to operate on top of the enp1s0 device. As the child device, the VLAN connection contains the IP, default gateway, and DNS configurations.

  2. Validate the playbook syntax:

    # ansible-playbook ~/vlan-ethernet.yml --syntax-check

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook:

    # ansible-playbook ~/vlan-ethernet.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.network/README.md file

8.6. Configuring a network bridge by using the network RHEL System Role

You can remotely configure a network bridge by using the network RHEL System Role.

Perform this procedure on the Ansible control node.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The managed nodes or groups of managed nodes on which you want to run this playbook are listed in the Ansible inventory file.
  • Two or more physical or virtual network devices are installed on the server.

Procedure

  1. Create a playbook file, for example ~/bridge-ethernet.yml, with the following content:

    ---
    - name: Configure the network
      hosts: managed-node-01.example.com
      tasks:
      - name: Configure a network bridge that uses two Ethernet ports
        include_role:
          name: rhel-system-roles.network
    
        vars:
          network_connections:
            # Define the bridge profile
            - name: bridge0
              type: bridge
              interface_name: bridge0
              ip:
                address:
                  - "192.0.2.1/24"
                  - "2001:db8:1::1/64"
                gateway4: 192.0.2.254
                gateway6: 2001:db8:1::fffe
                dns:
                  - 192.0.2.200
                  - 2001:db8:1::ffbb
                dns_search:
                  - example.com
              state: up
    
            # Add an Ethernet profile to the bridge
            - name: bridge0-port1
              interface_name: enp7s0
              type: ethernet
              controller: bridge0
              port_type: bridge
              state: up
    
            # Add a second Ethernet profile to the bridge
            - name: bridge0-port2
              interface_name: enp8s0
              type: ethernet
              controller: bridge0
              port_type: bridge
              state: up

    These settings define a network bridge with the following settings:

    • A static IPv4 address - 192.0.2.1 with a /24 subnet mask
    • A static IPv6 address - 2001:db8:1::1 with a /64 subnet mask
    • An IPv4 default gateway - 192.0.2.254
    • An IPv6 default gateway - 2001:db8:1::fffe
    • An IPv4 DNS server - 192.0.2.200
    • An IPv6 DNS server - 2001:db8:1::ffbb
    • A DNS search domain - example.com
    • Ports of the bridge - enp7s0 and enp8s0

      Note

      Set the IP configuration on the bridge and not on the ports of the Linux bridge.

  2. Validate the playbook syntax:

    # ansible-playbook ~/bridge-ethernet.yml --syntax-check

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook:

    # ansible-playbook ~/bridge-ethernet.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.network/README.md file

8.7. Configuring a network bond by using the network RHEL System Role

You can remotely configure a network bond by using the network RHEL System Role.

Perform this procedure on the Ansible control node.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The managed nodes or groups of managed nodes on which you want to run this playbook are listed in the Ansible inventory file.
  • Two or more physical or virtual network devices are installed on the server.

Procedure

  1. Create a playbook file, for example ~/bond-ethernet.yml, with the following content:

    ---
    - name: Configure the network
      hosts: managed-node-01.example.com
      tasks:
      - name: Configure a network bond that uses two Ethernet ports
        include_role:
          name: rhel-system-roles.network
    
        vars:
          network_connections:
            # Define the bond profile
            - name: bond0
              type: bond
              interface_name: bond0
              ip:
                address:
                  - "192.0.2.1/24"
                  - "2001:db8:1::1/64"
                gateway4: 192.0.2.254
                gateway6: 2001:db8:1::fffe
                dns:
                  - 192.0.2.200
                  - 2001:db8:1::ffbb
                dns_search:
                  - example.com
              bond:
                mode: active-backup
              state: up
    
            # Add an Ethernet profile to the bond
            - name: bond0-port1
              interface_name: enp7s0
              type: ethernet
              controller: bond0
              state: up
    
            # Add a second Ethernet profile to the bond
            - name: bond0-port2
              interface_name: enp8s0
              type: ethernet
              controller: bond0
              state: up

    These settings define a network bond with the following settings:

    • A static IPv4 address - 192.0.2.1 with a /24 subnet mask
    • A static IPv6 address - 2001:db8:1::1 with a /64 subnet mask
    • An IPv4 default gateway - 192.0.2.254
    • An IPv6 default gateway - 2001:db8:1::fffe
    • An IPv4 DNS server - 192.0.2.200
    • An IPv6 DNS server - 2001:db8:1::ffbb
    • A DNS search domain - example.com
    • Ports of the bond - enp7s0 and enp8s0
    • Bond mode - active-backup

      Note

      Set the IP configuration on the bond and not on the ports of the Linux bond.

  2. Validate the playbook syntax:

    # ansible-playbook ~/bond-ethernet.yml --syntax-check

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook:

    # ansible-playbook ~/bond-ethernet.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.network/README.md file

8.8. Configuring an IPoIB connection by using the network RHEL System Role

You can use the network RHEL System Role to remotely create NetworkManager connection profiles for IP over InfiniBand (IPoIB) devices. For example, remotely add an InfiniBand connection for the mlx4_ib0 interface with the following settings by running an Ansible Playbook:

  • An IPoIB device - mlx4_ib0.8002
  • A partition key p_key - 0x8002
  • A static IPv4 address - 192.0.2.1 with a /24 subnet mask
  • A static IPv6 address - 2001:db8:1::1 with a /64 subnet mask

Perform this procedure on the Ansible control node.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The managed nodes or groups of managed nodes on which you want to run this playbook are listed in the Ansible inventory file.
  • An InfiniBand device named mlx4_ib0 is installed in the managed nodes.
  • The managed nodes use NetworkManager to configure the network.

Procedure

  1. Create a playbook file, for example ~/IPoIB.yml, with the following content:

    ---
    - name: Configure the network
      hosts: managed-node-01.example.com
      tasks:
      - name: Configure IPoIB
        include_role:
          name: rhel-system-roles.network
    
        vars:
          network_connections:
    
            # InfiniBand connection mlx4_ib0
            - name: mlx4_ib0
              interface_name: mlx4_ib0
              type: infiniband
    
            # IPoIB device mlx4_ib0.8002 on top of mlx4_ib0
            - name: mlx4_ib0.8002
              type: infiniband
              autoconnect: yes
              infiniband:
                p_key: 0x8002
                transport_mode: datagram
              parent: mlx4_ib0
              ip:
                address:
                  - 192.0.2.1/24
                  - 2001:db8:1::1/64
              state: up

    If you set a p_key parameter as in this example, do not set an interface_name parameter on the IPoIB device.

  2. Validate the playbook syntax:

    # ansible-playbook ~/IPoIB.yml --syntax-check

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook:

    # ansible-playbook ~/IPoIB.yml

Verification

  1. On the managed-node-01.example.com host, display the IP settings of the mlx4_ib0.8002 device:

    # ip address show mlx4_ib0.8002
    ...
    inet 192.0.2.1/24 brd 192.0.2.255 scope global noprefixroute ib0.8002
       valid_lft forever preferred_lft forever
    inet6 2001:db8:1::1/64 scope link tentative noprefixroute
       valid_lft forever preferred_lft forever
  2. Display the partition key (P_Key) of the mlx4_ib0.8002 device:

    # cat /sys/class/net/mlx4_ib0.8002/pkey
    0x8002
  3. Display the mode of the mlx4_ib0.8002 device:

    # cat /sys/class/net/mlx4_ib0.8002/mode
    datagram

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.network/README.md file

8.9. Routing traffic from a specific subnet to a different default gateway by using the network RHEL System Role

You can use policy-based routing to configure a different default gateway for traffic from certain subnets. For example, you can configure RHEL as a router that, by default, routes all traffic to internet provider A using the default route. However, traffic received from the internal workstations subnet is routed to provider B.

To configure policy-based routing remotely and on multiple nodes, you can use the RHEL network System Role. Perform this procedure on the Ansible control node.

This procedure assumes the following network topology:

policy based routing

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on the them.
  • The managed nodes or groups of managed nodes on which you want to run this playbook are listed in the Ansible inventory file.
  • The managed nodes uses the NetworkManager and firewalld services.
  • The managed nodes you want to configure has four network interfaces:

    • The enp7s0 interface is connected to the network of provider A. The gateway IP in the provider’s network is 198.51.100.2, and the network uses a /30 network mask.
    • The enp1s0 interface is connected to the network of provider B. The gateway IP in the provider’s network is 192.0.2.2, and the network uses a /30 network mask.
    • The enp8s0 interface is connected to the 10.0.0.0/24 subnet with internal workstations.
    • The enp9s0 interface is connected to the 203.0.113.0/24 subnet with the company’s servers.
  • Hosts in the internal workstations subnet use 10.0.0.1 as the default gateway. In the procedure, you assign this IP address to the enp8s0 network interface of the router.
  • Hosts in the server subnet use 203.0.113.1 as the default gateway. In the procedure, you assign this IP address to the enp9s0 network interface of the router.

Procedure

  1. Create a playbook file, for example ~/pbr.yml, with the following content:

    ---
    - name: Configuring policy-based routing
      hosts: managed-node-01.example.com
      tasks:
      - name: Routing traffic from a specific subnet to a different default gateway
        include_role:
          name: rhel-system-roles.network
    
        vars:
          network_connections:
            - name: Provider-A
              interface_name: enp7s0
              type: ethernet
              autoconnect: True
              ip:
                address:
                  - 198.51.100.1/30
                gateway4: 198.51.100.2
                dns:
                  - 198.51.100.200
              state: up
              zone: external
    
            - name: Provider-B
              interface_name: enp1s0
              type: ethernet
              autoconnect: True
              ip:
                address:
                  - 192.0.2.1/30
                route:
                  - network: 0.0.0.0
                    prefix: 0
                    gateway: 192.0.2.2
                    table: 5000
              state: up
              zone: external
    
            - name: Internal-Workstations
              interface_name: enp8s0
              type: ethernet
              autoconnect: True
              ip:
                address:
                  - 10.0.0.1/24
                route:
                  - network: 10.0.0.0
                    prefix: 24
                    table: 5000
                routing_rule:
                  - priority: 5
                    from: 10.0.0.0/24
                    table: 5000
              state: up
              zone: trusted
    
            - name: Servers
              interface_name: enp9s0
              type: ethernet
              autoconnect: True
              ip:
                address:
                  - 203.0.113.1/24
              state: up
              zone: trusted
  2. Validate the playbook syntax:

    # ansible-playbook ~/pbr.yml --syntax-check

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook:

    # ansible-playbook ~/pbr.yml

Verification

  1. On a RHEL host in the internal workstation subnet:

    1. Install the traceroute package:

      # yum install traceroute
    2. Use the traceroute utility to display the route to a host on the internet:

      # traceroute redhat.com
      traceroute to redhat.com (209.132.183.105), 30 hops max, 60 byte packets
       1  10.0.0.1 (10.0.0.1)     0.337 ms  0.260 ms  0.223 ms
       2  192.0.2.1 (192.0.2.1)   0.884 ms  1.066 ms  1.248 ms
       ...

      The output of the command displays that the router sends packets over 192.0.2.1, which is the network of provider B.

  2. On a RHEL host in the server subnet:

    1. Install the traceroute package:

      # yum install traceroute
    2. Use the traceroute utility to display the route to a host on the internet:

      # traceroute redhat.com
      traceroute to redhat.com (209.132.183.105), 30 hops max, 60 byte packets
       1  203.0.113.1 (203.0.113.1)    2.179 ms  2.073 ms  1.944 ms
       2  198.51.100.2 (198.51.100.2)  1.868 ms  1.798 ms  1.549 ms
       ...

      The output of the command displays that the router sends packets over 198.51.100.2, which is the network of provider A.

  3. On the RHEL router that you configured using the RHEL System Role:

    1. Display the rule list:

      # ip rule list
      0:      from all lookup local
      5:    from 10.0.0.0/24 lookup 5000
      32766:  from all lookup main
      32767:  from all lookup default

      By default, RHEL contains rules for the tables local, main, and default.

    2. Display the routes in table 5000:

      # ip route list table 5000
      0.0.0.0/0 via 192.0.2.2 dev enp1s0 proto static metric 100
      10.0.0.0/24 dev enp8s0 proto static scope link src 192.0.2.1 metric 102
    3. Display the interfaces and firewall zones:

      # firewall-cmd --get-active-zones
      external
        interfaces: enp1s0 enp7s0
      trusted
        interfaces: enp8s0 enp9s0
    4. Verify that the external zone has masquerading enabled:

      # firewall-cmd --info-zone=external
      external (active)
        target: default
        icmp-block-inversion: no
        interfaces: enp1s0 enp7s0
        sources:
        services: ssh
        ports:
        protocols:
        masquerade: yes
        ...

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.network/README.md file

8.10. Configuring a static Ethernet connection with 802.1X network authentication by using the network RHEL System Role

You can remotely configure an Ethernet connection with 802.1X network authentication by using the network RHEL System Role.

Perform this procedure on the Ansible control node.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The managed nodes or groups of managed nodes on which you want to run this playbook are listed in the Ansible inventory file
  • The network supports 802.1X network authentication.
  • The managed nodes uses NetworkManager.
  • The following files required for TLS authentication exist on the control node:

    • The client key is stored in the /srv/data/client.key file.
    • The client certificate is stored in the /srv/data/client.crt file.
    • The Certificate Authority (CA) certificate is stored in the /srv/data/ca.crt file.

Procedure

  1. Create a playbook file, for example ~/enable-802.1x.yml, with the following content:

    ---
    - name: Configure an Ethernet connection with 802.1X authentication
      hosts: managed-node-01.example.com
      tasks:
        - name: Copy client key for 802.1X authentication
          copy:
            src: "/srv/data/client.key"
            dest: "/etc/pki/tls/private/client.key"
            mode: 0600
    
        - name: Copy client certificate for 802.1X authentication
          copy:
            src: "/srv/data/client.crt"
            dest: "/etc/pki/tls/certs/client.crt"
    
        - name: Copy CA certificate for 802.1X authentication
          copy:
            src: "/srv/data/ca.crt"
            dest: "/etc/pki/ca-trust/source/anchors/ca.crt"
    
        - include_role:
            name: rhel-system-roles.network
    
          vars:
            network_connections:
              - name: enp1s0
                type: ethernet
                autoconnect: yes
                ip:
                  address:
                    - 192.0.2.1/24
                    - 2001:db8:1::1/64
                  gateway4: 192.0.2.254
                  gateway6: 2001:db8:1::fffe
                  dns:
                    - 192.0.2.200
                    - 2001:db8:1::ffbb
                  dns_search:
                    - example.com
                ieee802_1x:
                  identity: user_name
                  eap: tls
                  private_key: "/etc/pki/tls/private/client.key"
                  private_key_password: "password"
                  client_cert: "/etc/pki/tls/certs/client.crt"
                  ca_cert: "/etc/pki/ca-trust/source/anchors/ca.crt"
                  domain_suffix_match: example.com
                state: up

    These settings define an Ethernet connection profile for the enp1s0 device with the following settings:

    • A static IPv4 address - 192.0.2.1 with a /24 subnet mask
    • A static IPv6 address - 2001:db8:1::1 with a /64 subnet mask
    • An IPv4 default gateway - 192.0.2.254
    • An IPv6 default gateway - 2001:db8:1::fffe
    • An IPv4 DNS server - 192.0.2.200
    • An IPv6 DNS server - 2001:db8:1::ffbb
    • A DNS search domain - example.com
    • 802.1X network authentication using the TLS Extensible Authentication Protocol (EAP)
  2. Validate the playbook syntax:

    # ansible-playbook ~/enable-802.1x.yml --syntax-check

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook:

    # ansible-playbook ~/enable-802.1x.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.network/README.md file

8.11. Setting the default gateway on an existing connection by using the network RHEL System Role

You can use the network RHEL System Role to set the default gateway.

Important

When you run a play that uses the network RHEL System Role, the system role overrides an existing connection profile with the same name if the value of settings does not match the ones specified in the play. Therefore, always specify the whole configuration of the network connection profile in the play, even if, for example, the IP configuration already exists. Otherwise, the role resets these values to their defaults.

Depending on whether it already exists, the procedure creates or updates the enp1s0 connection profile with the following settings:

  • A static IPv4 address - 198.51.100.20 with a /24 subnet mask
  • A static IPv6 address - 2001:db8:1::1 with a /64 subnet mask
  • An IPv4 default gateway - 198.51.100.254
  • An IPv6 default gateway - 2001:db8:1::fffe
  • An IPv4 DNS server - 198.51.100.200
  • An IPv6 DNS server - 2001:db8:1::ffbb
  • A DNS search domain - example.com

Perform this procedure on the Ansible control node.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The managed nodes or groups of managed nodes on which you want to run this playbook are listed in the Ansible inventory file.

Procedure

  1. Create a playbook file, for example ~/ethernet-connection.yml, with the following content:

    ---
    - name: Configure the network
      hosts: managed-node-01.example.com
      tasks:
      - name: Configure an Ethernet connection with static IP and default gateway
        include_role:
          name: rhel-system-roles.network
    
        vars:
          network_connections:
            - name: enp1s0
              type: ethernet
              autoconnect: yes
              ip:
                address:
                  - 198.51.100.20/24
                  - 2001:db8:1::1/64
                gateway4: 198.51.100.254
                gateway6: 2001:db8:1::fffe
                dns:
                  - 198.51.100.200
                  - 2001:db8:1::ffbb
                dns_search:
                  - example.com
              state: up
  2. Validate the playbook syntax:

    # ansible-playbook ~/ethernet-connection.yml --syntax-check

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook:

    # ansible-playbook ~/ethernet-connection.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.network/README.md file

8.12. Configuring a static route by using the network RHEL System Role

You can use the network RHEL System Role to configure static routes.

Important

When you run a play that uses the network RHEL System Role, the system role overrides an existing connection profile with the same name if the value of settings does not match the ones specified in the play. Therefore, always specify the whole configuration of the network connection profile in the play, even if, for example, the IP configuration already exists. Otherwise, the role resets these values to their defaults.

Perform this procedure on the Ansible control node.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The managed nodes or groups of managed nodes on which you want to run this playbook are listed in the Ansible inventory file.

Procedure

  1. Create a playbook file, for example ~/add-static-routes.yml, with the following content:

    ---
    - name: Configure the network
      hosts: managed-node-01.example.com
      tasks:
      - name: Configure an Ethernet connection with static IP and additional routes
        include_role:
          name: rhel-system-roles.network
    
        vars:
          network_connections:
            - name: enp7s0
              type: ethernet
              autoconnect: yes
              ip:
                address:
                  - 192.0.2.1/24
                  - 2001:db8:1::1/64
                gateway4: 192.0.2.254
                gateway6: 2001:db8:1::fffe
                dns:
                  - 192.0.2.200
                  - 2001:db8:1::ffbb
                dns_search:
                  - example.com
                route:
                  - network: 198.51.100.0
                    prefix: 24
                    gateway: 192.0.2.10
                  - network: 2001:db8:2::
                    prefix: 64
                    gateway: 2001:db8:1::10
              state: up

    Depending on whether it already exists, the procedure creates or updates the enp7s0 connection profile with the following settings:

    • A static IPv4 address - 192.0.2.1 with a /24 subnet mask
    • A static IPv6 address - 2001:db8:1::1 with a /64 subnet mask
    • An IPv4 default gateway - 192.0.2.254
    • An IPv6 default gateway - 2001:db8:1::fffe
    • An IPv4 DNS server - 192.0.2.200
    • An IPv6 DNS server - 2001:db8:1::ffbb
    • A DNS search domain - example.com
    • Static routes:

      • 198.51.100.0/24 with gateway 192.0.2.10
      • 2001:db8:2::/64 with gateway 2001:db8:1::10
  2. Validate the playbook syntax:

    # ansible-playbook ~/add-static-routes.yml --syntax-check

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook:

    # ansible-playbook ~/add-static-routes.yml

Verification

  1. On the managed nodes:

    1. Display the IPv4 routes:

      # ip -4 route
      ...
      198.51.100.0/24 via 192.0.2.10 dev enp7s0
    2. Display the IPv6 routes:

      # ip -6 route
      ...
      2001:db8:2::/64 via 2001:db8:1::10 dev enp7s0 metric 1024 pref medium

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.network/README.md file

8.13. Configuring an ethtool offload feature by using the network RHEL System Role

You can use the network RHEL System Role to configure ethtool features of a NetworkManager connection.

Important

When you run a play that uses the network RHEL System Role, the system role overrides an existing connection profile with the same name if the value of settings does not match the ones specified in the play. Therefore, always specify the whole configuration of the network connection profile in the play, even if, for example the IP configuration, already exists. Otherwise the role resets these values to their defaults.

Perform this procedure on the Ansible control node.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The managed nodes or groups of managed nodes on which you want to run this playbook are listed in the Ansible inventory file.

Procedure

  1. Create a playbook file, for example ~/configure-ethernet-device-with-ethtool-features.yml, with the following content:

    ---
    - name: Configure the network
      hosts: managed-node-01.example.com
      tasks:
      - name: Configure an Ethernet connection with ethtool features
        include_role:
          name: rhel-system-roles.network
    
        vars:
          network_connections:
            - name: enp1s0
              type: ethernet
              autoconnect: yes
              ip:
                address:
                  - 198.51.100.20/24
                  - 2001:db8:1::1/64
                gateway4: 198.51.100.254
                gateway6: 2001:db8:1::fffe
                dns:
                  - 198.51.100.200
                  - 2001:db8:1::ffbb
                dns_search:
                  - example.com
              ethtool:
                features:
                  gro: "no"
                  gso: "yes"
                  tx_sctp_segmentation: "no"
              state: up

    Depending on whether it already exists, this playbook creates or updates the enp1s0 connection profile with the following settings:

    • A static IPv4 address - 198.51.100.20 with a /24 subnet mask
    • A static IPv6 address - 2001:db8:1::1 with a /64 subnet mask
    • An IPv4 default gateway - 198.51.100.254
    • An IPv6 default gateway - 2001:db8:1::fffe
    • An IPv4 DNS server - 198.51.100.200
    • An IPv6 DNS server - 2001:db8:1::ffbb
    • A DNS search domain - example.com
    • ethtool features:

      • Generic receive offload (GRO): disabled
      • Generic segmentation offload (GSO): enabled
      • TX stream control transmission protocol (SCTP) segmentation: disabled
  2. Validate the playbook syntax:

    # ansible-playbook ~/configure-ethernet-device-with-ethtool-features.yml --syntax-check

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook:

    # ansible-playbook ~/configure-ethernet-device-with-ethtool-features.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.network/README.md file

8.14. Configuring an ethtool coalesce settings by using the network RHEL System Role

You can use the network RHEL System Role to configure ethtool coalesce settings of a NetworkManager connection.

Important

When you run a play that uses the network RHEL System Role, the system role overrides an existing connection profile with the same name if the value of settings does not match the ones specified in the play. Therefore, always specify the whole configuration of the network connection profile in the play, even if, for example the IP configuration, already exists. Otherwise the role resets these values to their defaults.

Perform this procedure on the Ansible control node.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The managed nodes or groups of managed nodes on which you want to run this playbook are listed in the Ansible inventory file.

Procedure

  1. Create a playbook file, for example ~/configure-ethernet-device-with-ethtoolcoalesce-settings.yml, with the following content:

    ---
    - name: Configure the network
      hosts: managed-node-01.example.com
      tasks:
      - name: Configure an Ethernet connection with ethtool coalesce settings
        include_role:
          name: rhel-system-roles.network
    
        vars:
          network_connections:
            - name: enp1s0
              type: ethernet
              autoconnect: yes
              ip:
                address:
                  - 198.51.100.20/24
                  - 2001:db8:1::1/64
                gateway4: 198.51.100.254
                gateway6: 2001:db8:1::fffe
                dns:
                  - 198.51.100.200
                  - 2001:db8:1::ffbb
                dns_search:
                  - example.com
              ethtool:
                coalesce:
                  rx_frames: 128
                  tx_frames: 128
              state: up

    Depending on whether it already exists, this playbook creates or updates the enp1s0 connection profile with the following settings:

    • A static IPv4 address - 198.51.100.20 with a /24 subnet mask
    • A static IPv6 address - 2001:db8:1::1 with a /64 subnet mask
    • An IPv4 default gateway - 198.51.100.254
    • An IPv6 default gateway - 2001:db8:1::fffe
    • An IPv4 DNS server - 198.51.100.200
    • An IPv6 DNS server - 2001:db8:1::ffbb
    • A DNS search domain - example.com
    • ethtool coalesce settings:

      • RX frames: 128
      • TX frames: 128
  2. Validate the playbook syntax:

    # ansible-playbook ~/configure-ethernet-device-with-ethtoolcoalesce-settings.yml --syntax-check

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook:

    # ansible-playbook ~/configure-ethernet-device-with-ethtoolcoalesce-settings.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.network/README.md file

8.15. Network states for the network RHEL System role

The network RHEL system role supports state configurations in playbooks to configure the devices. For this, use the network_state variable followed by the state configurations.

Benefits of using the network_state variable in a playbook:

  • Using the declarative method with the state configurations, you can configure interfaces, and the NetworkManager creates a profile for these interfaces in the background.
  • With the network_state variable, you can specify the options that you require to change, and all the other options will remain the same as they are. However, with the network_connections variable, you must specify all settings to change the network connection profile.

For example, to create an Ethernet connection with dynamic IP address settings, use the following vars block in your playbook:

Playbook with state configurations

Regular playbook

vars:
  network_state:
    interfaces:
    - name: enp7s0
      type: ethernet
      state: up
      ipv4:
        enabled: true
        auto-dns: true
        auto-gateway: true
        auto-routes: true
        dhcp: true
      ipv6:
        enabled: true
        auto-dns: true
        auto-gateway: true
        auto-routes: true
        autoconf: true
        dhcp: true
vars:
  network_connections:
    - name: enp7s0
      interface_name: enp7s0
      type: ethernet
      autoconnect: yes
      ip:
        dhcp4: yes
        auto6: yes
      state: up

For example, to only change the connection status of dynamic IP address settings that you created as above, use the following vars block in your playbook:

Playbook with state configurations

Regular playbook

vars:
  network_state:
    interfaces:
    - name: enp7s0
      type: ethernet
      state: down
vars:
  network_connections:
    - name: enp7s0
      interface_name: enp7s0
      type: ethernet
      autoconnect: yes
      ip:
        dhcp4: yes
        auto6: yes
      state: down

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.network/README.md file

Chapter 9. Configuring firewalld by using RHEL System Roles

You can use the firewall System Role to configure settings of the firewalld service on multiple clients at once. This solution:

  • Provides an interface with efficient input settings.
  • Keeps all intended firewalld parameters in one place.

After you run the firewall role on the control node, the System Role applies the firewalld parameters to the managed node immediately and makes them persistent across reboots.

9.1. Introduction to the firewall RHEL System Role

RHEL System Roles is a set of contents for the Ansible automation utility. This content together with the Ansible automation utility provides a consistent configuration interface to remotely manage multiple systems.

The rhel-system-roles.firewall role from the RHEL System Roles was introduced for automated configurations of the firewalld service. The rhel-system-roles package contains this System Role, and also the reference documentation.

To apply the firewalld parameters on one or more systems in an automated fashion, use the firewall System Role variable in a playbook. A playbook is a list of one or more plays that is written in the text-based YAML format.

You can use an inventory file to define a set of systems that you want Ansible to configure.

With the firewall role you can configure many different firewalld parameters, for example:

  • Zones.
  • The services for which packets should be allowed.
  • Granting, rejection, or dropping of traffic access to ports.
  • Forwarding of ports or port ranges for a zone.

Additional resources

9.2. Resetting the firewalld settings by using a RHEL System Role

With the firewall RHEL system role, you can reset the firewalld settings to their default state. If you add the previous:replaced parameter to the variable list, the System Role removes all existing user-defined settings and resets firewalld to the defaults. If you combine the previous:replaced parameter with other settings, the firewall role removes all existing settings before applying new ones.

Perform this procedure on the Ansible control node.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on the them.
  • The managed nodes or groups of managed nodes on which you want to run this playbook are listed in the Ansible inventory file.

Procedure

  1. Create a playbook file, for example ~/reset-firewalld.yml, with the following content:

    ---
    - name: Reset firewalld example
      hosts: managed-node-01.example.com
      tasks:
      - name: Reset firewalld
        include_role:
          name: rhel-system-roles.firewall
    
        vars:
          firewall:
            - previous: replaced
  2. Validate the playbook syntax:

    # ansible-playbook ~/configure-ethernet-device-with-ethtoolcoalesce-settings.yml --syntax-check

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook:

    # ansible-playbook ~/reset-firewalld.yml

Verification

  • Run this command as root on the managed node to check all the zones:

    # firewall-cmd --list-all-zones

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.firewall/README.md

9.3. Forwarding incoming traffic in firewalld from one local port to a different local port by using a RHEL System Role

With the firewall role you can remotely configure firewalld parameters with persisting effect on multiple managed hosts.

Perform this procedure on the Ansible control node.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on the them.
  • The managed nodes or groups of managed nodes on which you want to run this playbook are listed in the Ansible inventory file.

Procedure

  1. Create a playbook file, for example ~/port_forwarding.yml, with the following content:

    ---
    - name: Configure firewalld
      hosts: managed-node-01.example.com
      tasks:
      - name: Forward incoming traffic on port 8080 to 443
        include_role:
          name: rhel-system-roles.firewall
    
        vars:
          firewall:
            - { forward_port: 8080/tcp;443;, state: enabled, runtime: true, permanent: true }
  2. Validate the playbook syntax:

    # ansible-playbook ~/port_forwarding.yml --syntax-check

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook:

    # ansible-playbook ~/port_forwarding.yml

Verification

  • On the managed host, display the firewalld settings:

    # firewall-cmd --list-forward-ports

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.firewall/README.md

9.4. Managing ports in firewalld by using a RHEL System Role

You can use the RHEL firewall System Role to open or close ports in the local firewall for incoming traffic and make the new configuration persist across reboots. For example you can configure the default zone to permit incoming traffic for the HTTPS service.

Perform this procedure on the Ansible control node.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on the them.
  • The managed nodes or groups of managed nodes on which you want to run this playbook are listed in the Ansible inventory file.

Procedure

  1. Create a playbook file, for example ~/opening-a-port.yml, with the following content:

    ---
    - name: Configure firewalld
      hosts: managed-node-01.example.com
      tasks:
      - name: Allow incoming HTTPS traffic to the local host
        include_role:
          name: rhel-system-roles.firewall
    
        vars:
          firewall:
            - port: 443/tcp
              service: http
              state: enabled
              runtime: true
              permanent: true

    The permanent: true option makes the new settings persistent across reboots.

  2. Validate the playbook syntax:

    # ansible-playbook ~/opening-a-port.yml --syntax-check

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook:

    # ansible-playbook ~/opening-a-port.yml

Verification

  • On the managed node, verify that the 443/tcp port associated with the HTTPS service is open:

    # firewall-cmd --list-ports
    443/tcp

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.firewall/README.md

9.5. Configuring a firewalld DMZ zone by using a RHEL System Role

As a system administrator, you can use the firewall System Role to configure a dmz zone on the enp1s0 interface to permit HTTPS traffic to the zone. In this way, you enable external users to access your web servers.

Perform this procedure on the Ansible control node.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on the them.
  • The managed nodes or groups of managed nodes on which you want to run this playbook are listed in the Ansible inventory file.

Procedure

  1. Create a playbook file, for example ~/configuring-a-dmz.yml, with the following content:

    ---
    - name: Configure firewalld
      hosts: managed-node-01.example.com
      tasks:
      - name: Creating a DMZ with access to HTTPS port and masquerading for hosts in DMZ
        include_role:
          name: rhel-system-roles.firewall
    
        vars:
          firewall:
            - zone: dmz
              interface: enp1s0
              service: https
              state: enabled
              runtime: true
              permanent: true
  2. Validate the playbook syntax:

    # ansible-playbook ~/configuring-a-dmz.yml --syntax-check

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook:

    # ansible-playbook ~/configuring-a-dmz.yml

Verification

  • On the managed node, view detailed information about the dmz zone:

    # firewall-cmd --zone=dmz --list-all
    dmz (active)
      target: default
      icmp-block-inversion: no
      interfaces: enp1s0
      sources:
      services: https ssh
      ports:
      protocols:
      forward: no
      masquerade: no
      forward-ports:
      source-ports:
      icmp-blocks:

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.firewall/README.md

Chapter 10. Configuring Postfix MTA by using RHEL System Roles

With the postfix role, you can consistently streamline automated configurations of the Postfix service, a Sendmail-compatible mail transfer agent (MTA) with modular design and a variety of configuration options. The rhel-system-roles package contains this System Role, and also the reference documentation.

10.1. Using the postfix System Role to automate basic Postfix MTA administration

You can install, configure and start the Postfix Mail Transfer Agent on the managed nodes by using the postfix RHEL System Role.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The managed nodes or groups of managed nodes on which you want to run this playbook are listed in the Ansible inventory file.

Procedure

  1. Create a playbook that defines the postfix role:

    1. Create a new YAML file, for example ~/postfix-playbook.yml, and open it in a text editor, for example:

      # vi postfix-playbook.yml
    2. Configure the relay_domains=$mydestination and relayhost=example.com variables:

      - name: Manage postfix
        hosts: all
        vars:
      	postfix_conf:
        		relay_domains: $mydestination
        		relayhost: example.com
        roles:
      	- linux-system-roles.postfix
    3. If you want Postfix to use a different hostname than the fully-qualified domain name (FQDN) that is returned by the gethostname() function, add the myhostname parameter under the postfix_conf: line in the file:

      myhostname = smtp.example.com
    4. If the domain name differs from the domain name in the myhostname parameter, add the mydomain parameter. Otherwise, the $myhostname minus the first component is used.

      mydomain = <example.com>
    5. Use postfix_manage_firewall: true variable to ensure that the SMTP port is open in the firewall on the servers.

      Manage the SMTP related ports, 25/tcp, 465/tcp, and 587/tcp. If the variable is set to false, the postfix role does not manage the firewall. The default is false.

      Note

      The postfix_manage_firewall variable is limited to adding ports. It cannot be used for removing ports. If you want to remove ports, use the firewall RHEL System Role directly.

    6. If your scenario involves using non-standard ports, set the postfix_manage_selinux: true variable to ensure that the port is properly labeled for SELinux on the servers.

      Note

      The postfix_manage_selinux variable is limited to adding rules to the SELinux policy. It cannot remove rules from the policy. If you want to remove rules, use the selinux System Role directly.

  2. Run the playbook on a specific inventory:

    # ansible-playbook -i <inventory-file> </path/to/file/postfix-playbook.yml>

    Where:

    • <inventory-file> is the inventory file.
    • <postfix-playbook.yml> is the playbook you use.

Additional resources

10.2. Selected variables for the postfix RHEL System Role

You can customize the configuration of the Postfix Mail Transfer Agent (MTA) by using variables of the postfix RHEL System Role.

Use the following variables for a basic configuration. See the documentation installed with the rhel-system-roles package for more variables.

postfix_conf

Use this variable to include key or value pairs of all the supported postfix configuration parameters. By default, postfix_conf does not have a value.

postfix_conf:
  relayhost: example.com
previous: replaced

Use this variable to remove any existing configuration and apply the desired configuration on top of a clean postfix installation:

postfix_conf:
  relayhost: example.com
  previous: replaced
postfix_check

Use this variable to determine whether a check has been executed before starting the postfix role to verify the configuration changes. The default value is true.

For example:

postfix_check: true
postfix_backup

Use this variable to create a single backup copy of the configuration by setting the variable to true. The default value is false.

To overwrite any previous backup, enter the following command:

# cp /etc/postfix/main.cf /etc/postfix/main.cf.backup

If the postfix_backup value is changed to true, you must also set the postfix_backup_multiple value to false:

postfix_backup: true
postfix_backup_multiple: false
postfix_backup_multiple

Use this variable to make a timestamped backup copy of the configuration by setting it to true. The default value is true.

To keep multiple backup copies, enter the following command:

# cp /etc/postfix/main.cf /etc/postfix/main.cf.$(date -Isec)

The postfix_backup_multiple:true setting overrides postfix_backup. If you want to use postfix_backup, you must set the postfix_backup_multiple:false.

postfix_manage_firewall
Use this variable to integrate the postfix role with the firewall role to manage port access. By default, the variable is set to false. If you want to automatically manage port access from the postfix role, set the variable to true.
postfix_manage_selinux
Use this variable to integrate the postfix role with the selinux role to manage port access. By default, the variable is set to false. If you want to automatically manage port access from the postfix role, set the variable to true.

Chapter 11. Configuring SELinux by using System Roles

You can configure and manage SELinux permissions on other systems by using the selinux RHEL System Role.

11.1. Introduction to the selinux System Role

RHEL System Roles is a collection of Ansible roles and modules that provide a consistent configuration interface to remotely manage multiple RHEL systems. The selinux System Role enables the following actions:

  • Cleaning local policy modifications related to SELinux booleans, file contexts, ports, and logins.
  • Setting SELinux policy booleans, file contexts, ports, and logins.
  • Restoring file contexts on specified files or directories.
  • Managing SELinux modules.

The following table provides an overview of input variables available in the selinux System Role.

Table 11.1. selinux System Role variables

Role variableDescriptionCLI alternative

selinux_policy

Chooses a policy protecting targeted processes or Multi Level Security protection.

SELINUXTYPE in /etc/selinux/config

selinux_state

Switches SELinux modes.

setenforce and SELINUX in /etc/selinux/config.

selinux_booleans

Enables and disables SELinux booleans.

setsebool

selinux_fcontexts

Adds or removes a SELinux file context mapping.

semanage fcontext

selinux_restore_dirs

Restores SELinux labels in the file-system tree.

restorecon -R

selinux_ports

Sets SELinux labels on ports.

semanage port

selinux_logins

Sets users to SELinux user mapping.

semanage login

selinux_modules

Installs, enables, disables, or removes SELinux modules.

semodule

The /usr/share/doc/rhel-system-roles/selinux/example-selinux-playbook.yml example playbook installed by the rhel-system-roles package demonstrates how to set the targeted policy in enforcing mode. The playbook also applies several local policy modifications and restores file contexts in the /tmp/test_dir/ directory.

For a detailed reference on selinux role variables, install the rhel-system-roles package, and see the README.md or README.html files in the /usr/share/doc/rhel-system-roles/selinux/ directory.

Additional resources

11.2. Using the selinux System Role to apply SELinux settings on multiple systems

Follow the steps to prepare and apply an Ansible playbook with your verified SELinux settings.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The managed nodes or groups of managed nodes on which you want to run this playbook are listed in the Ansible inventory file.

Procedure

  1. Prepare your playbook. You can either start from the scratch or modify the example playbook installed as a part of the rhel-system-roles package:

    # cp /usr/share/doc/rhel-system-roles/selinux/example-selinux-playbook.yml my-selinux-playbook.yml
    # vi my-selinux-playbook.yml
  2. Change the content of the playbook to fit your scenario. For example, the following part ensures that the system installs and enables the selinux-local-1.pp SELinux module:

    selinux_modules:
    - { path: "selinux-local-1.pp", priority: "400" }
  3. Save the changes, and exit the text editor.
  4. Run your playbook on the host1, host2, and host3 systems:

    # ansible-playbook -i host1,host2,host3 my-selinux-playbook.yml

Additional resources

  • For more information, install the rhel-system-roles package, and see the /usr/share/doc/rhel-system-roles/selinux/ and /usr/share/ansible/roles/rhel-system-roles.selinux/ directories.

11.3. Overriding the system-wide cryptographic policy on an SSH server by using System Roles

You can override the system-wide cryptographic policy on an SSH server by using the sshd RHEL System Role.

Perform this procedure on the Ansible control node.

Prerequisites

  • You have prepared the control node and the managed nodes
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The managed nodes or groups of managed nodes on which you want to run this playbook are listed in the Ansible inventory file.

Procedure

  1. Create a playbook that uses the required role:

    1. Create a new YAML file and open it in a text editor, for example:

      # vi <cryptographic-playbook.yml>
    2. Insert the following example:

      ---
      - name: Overriding the system-wide cryptographic policy
        hosts: all
        become: true
        roles:
          - rhel_system_roles.sshd
        vars:
          sshd_sysconfig: true
          sshd_sysconfig_override_crypto_policy: true
          sshd_KexAlgorithms: ecdh-sha2-nistp521
          sshd_Ciphers: aes256-ctr
          sshd_MACs: hmac-sha2-512-etm@openssh.com
          sshd_HostKeyAlgorithms: rsa-sha2-512,rsa-sha2-256

      On RHEL 9 managed nodes, the system role writes the configuration into the /etc/ssh/sshd_config.d/00-ansible_system_role.conf file, where cryptographic options are applied automatically. You can change the file by using the sshd_config_file variable. However, to ensure the configuration is effective, use a file name that lexicographicaly preceeds the /etc/ssh/sshd_config.d/50-redhat.conf file, which includes the configured crypto policies. For more information, see Examples of opting out of system-wide crypto policies.

      On RHEL 8 managed nodes, you must enable override by setting the sshd_sysconfig_override_crypto_policy and sshd_sysconfig variables to true.

      You can further customize the configuration on the SSH server by using the following variables of the rhel_system_roles.sshd RHEL System Role:

      sshd_Ciphers
      You can choose ciphers, for example, aes128-ctr, aes192-ctr, or aes256-ctr.
      sshd_MACs
      You can choose MACs, for example, hmac-sha2-256, hmac-sha2-512, or hmac-sha1.
      sshd_HostKeyAlgorithms
      You can choose a public key algorithm, for example, ecdsa-sha2-nistp256, ecdsa-sha2-nistp384, ecdsa-sha2-nistp521, ssh-rsa, or ssh-dss.
      sshd_KexAlgorithms

      You can choose key exchange algorithms, for example, ecdh-sha2-nistp256, ecdh-sha2-nistp384, ecdh-sha2-nistp521,diffie-hellman-group14-sha1, or diffie-hellman-group-exchange-sha256.

      For more variables and their possible values, see the sshd_config(5) man page.

  2. Run the playbook:

    $ ansible-playbook <cryptographic-playbook.yml>

Verification

  1. You can verify the success of the procedure by using the verbose SSH connection and check the defined variables in the following output:

    $ ssh -vvv localhost
    ...
    debug2: peer server KEXINIT proposal
    debug2: KEX algorithms: ecdh-sha2-nistp521
    debug2: host key algorithms: rsa-sha2-512,rsa-sha2-256
    debug2: ciphers ctos: aes256-ctr
    debug2: ciphers stoc: aes256-ctr
    debug2: MACs ctos: hmac-sha2-512-etm@openssh.com
    debug2: MACs stoc: hmac-sha2-512-etm@openssh.com
    ...

Chapter 12. Managing systemd units by using the systemd RHEL System Role

With the systemd System Role you can deploy unit files and manage systemd units on multiple systems by using the Red Hat Ansible Automation Platform.

You can use the systemd_units variable in systemd System Role playbooks to gain insights into the status of systemd units on a target system. The variable displays a list of dictionaries. Each dictionary entry describes the state and configuration of one systemd unit present on the managed host. The systemd_units variable is updated as the final step of task execution and captures the state after the role has run all tasks.

12.1. Variables for the systemd RHEL System Role

You can customize the behavior of the systemd system and service manager by setting the following input variables for the systemd RHEL System Role:

systemd_unit_files
Specifies a list of systemd unit file names that you want to deploy to the target hosts.
systemd_unit-file_templates
Specifies a list of systemd unit file names that should be treated as templates. Each name should correspond to the Jinja template file. For example, for a <name>.service unit file, you can either have the <name>.service Jinja template file or the <name>.service.j2 Jinja template file. If your local template file has a .j2 suffix, Ansible removes the suffix before creating the final unit file name.
systemd_dropins

Specifies a list of systemd drop-in configuration files to modify or enhance the behavior of a systemd unit without making changes to the unit file directly.

When you set the systemd_dropins = <name>.service.conf variable in the playbook, Ansible takes the local <name>.service.conf file and creates a drop-in file on the managed node named always 99-override.conf and uses this drop-in file to modify the <name>.service systemd unit.

systemd_started_units
Specifies the list of unit names that systemd starts.
systemd_stopped_units
Use this variable to specify the list of unit names that systemd should stop.
systemd_restarted_units
Specifies a list of unit names that systemd should restart.
systemd_reloaded_units
Specifies a list of unit names that systemd should reload.
systemd_enabled_units
Specifies a list of unit names that systemd should enable.
systemd_disabled_units
Specifies a list of unit names that systemd should disable.
systemd_masked_units
Specifies a list of unit names that systemd should mask.
systemd_unmasked_units
Specifies a list of unit names that systemd should unmask.

12.2. Deploying and starting a systemd unit by using the systemd System Role

You can apply the systemd RHEL System Role to perform tasks related to systemd unit management on the target hosts. You will set the systemd System Role variables in a playbook to define which unit files systemd manages, starts, and enables.

Prerequisites

  • You have prepared the control node and the managed nodes
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The managed nodes or groups of managed nodes on which you want to run this playbook are listed in the Ansible inventory file.

Procedure

  1. Create a new playbook.yml file with the following content:

    - name: Deploy and start systemd unit
      hosts: all
      vars:
        systemd_unit_files:
          - <name1>.service
          - <name2>.service
          - <name3>.service
        systemd_started_units:
          - <name1>.service
          - <name2>.service
          - <name3>.service
        systemd_enabled_units:
          - <name1>.service
          - <name2>.service
          - <name3>.service
      roles:
        - linux-system-roles.systemd
  2. Optional: Verify playbook syntax:

    # ansible-playbook --syntax-check playbook.yml -i inventory_file
  3. Run the playbook on your inventory file:

    # ansible-playbook -i inventory_file /path/to/file/playbook.yml

12.3. Additional resources

  • The ansible-playbook(1) man page

Chapter 13. Configuring logging by using RHEL System Roles

As a system administrator, you can use the logging System Role to configure a RHEL host as a logging server to collect logs from many client systems.

13.1. The logging System Role

With the logging System Role, you can deploy logging configurations on local and remote hosts.

To apply a logging System Role on one or more systems, you define the logging configuration in a playbook. A playbook is a list of one or more plays. Playbooks are human-readable, and they are written in the YAML format. For more information about playbooks, see Working with playbooks in Ansible documentation.

The set of systems that you want to configure according to the playbook is defined in an inventory file. For more information about creating and using inventories, see How to build your inventory in Ansible documentation.

Logging solutions provide multiple ways of reading logs and multiple logging outputs.

For example, a logging system can receive the following inputs:

  • Local files
  • systemd/journal
  • Another logging system over the network

In addition, a logging system can have the following outputs:

  • Logs stored in the local files in the /var/log directory
  • Logs sent to Elasticsearch
  • Logs forwarded to another logging system

With the logging System Role, you can combine the inputs and outputs to fit your scenario. For example, you can configure a logging solution that stores inputs from journal in a local file, whereas inputs read from files are both forwarded to another logging system and stored in the local log files.

13.2. logging System Role parameters

In a logging System Role playbook, you define the inputs in the logging_inputs parameter, outputs in the logging_outputs parameter, and the relationships between the inputs and outputs in the logging_flows parameter. The logging System Role processes these variables with additional options to configure the logging system. You can also enable encryption or an automatic port management.

Note

Currently, the only available logging system in the logging System Role is Rsyslog.

  • logging_inputs: List of inputs for the logging solution.

    • name: Unique name of the input. Used in the logging_flows: inputs list and a part of the generated config file name.
    • type: Type of the input element. The type specifies a task type which corresponds to a directory name in roles/rsyslog/{tasks,vars}/inputs/.

      • basics: Inputs configuring inputs from systemd journal or unix socket.

        • kernel_message: Load imklog if set to true. Default to false.
        • use_imuxsock: Use imuxsock instead of imjournal. Default to false.
        • ratelimit_burst: Maximum number of messages that can be emitted within ratelimit_interval. Default to 20000 if use_imuxsock is false. Default to 200 if use_imuxsock is true.
        • ratelimit_interval: Interval to evaluate ratelimit_burst. Default to 600 seconds if use_imuxsock is false. Default to 0 if use_imuxsock is true. 0 indicates rate limiting is turned off.
        • persist_state_interval: Journal state is persisted every value messages. Default to 10. Effective only when use_imuxsock is false.
      • files: Inputs configuring inputs from local files.
      • remote: Inputs configuring inputs from the other logging system over network.
    • state: State of the configuration file. present or absent. Default to present.
  • logging_outputs: List of outputs for the logging solution.

    • files: Outputs configuring outputs to local files.
    • forwards: Outputs configuring outputs to another logging system.
    • remote_files: Outputs configuring outputs from another logging system to local files.
  • logging_flows: List of flows that define relationships between logging_inputs and logging_outputs. The logging_flows variable has the following keys:

    • name: Unique name of the flow
    • inputs: List of logging_inputs name values
    • outputs: List of logging_outputs name values.
  • logging_manage_firewall: If set to true, the logging role uses the firewall role to automatically manage port access.
  • logging_manage_selinux: If set to true, the logging role uses the selinux role to automatically manage port access.

Additional resources

  • Documentation installed with the rhel-system-roles package in /usr/share/ansible/roles/rhel-system-roles.logging/README.html

13.3. Applying a local logging System Role

Prepare and apply an Ansible playbook to configure a logging solution on a set of separate machines. Each machine records logs locally.

Prerequisites

  • Access and permissions to one or more managed nodes, which are systems you want to configure with the logging System Role.
  • Access and permissions to a control node, which is a system from which Red Hat Ansible Core configures other systems.

    On the control node:

    • The ansible-core and rhel-system-roles packages are installed.
Important

RHEL 8.0-8.5 provided access to a separate Ansible repository that contains Ansible Engine 2.9 for automation based on Ansible. Ansible Engine contains command-line utilities such as ansible, ansible-playbook, connectors such as docker and podman, and many plugins and modules. For information about how to obtain and install Ansible Engine, see the How to download and install Red Hat Ansible Engine Knowledgebase article.

RHEL 8.6 and 9.0 have introduced Ansible Core (provided as the ansible-core package), which contains the Ansible command-line utilities, commands, and a small set of built-in Ansible plugins. RHEL provides this package through the AppStream repository, and it has a limited scope of support. For more information, see the Scope of support for the Ansible Core package included in the RHEL 9 and RHEL 8.6 and later AppStream repositories Knowledgebase article.

  • An inventory file which lists the managed nodes.
Note

You do not have to have the rsyslog package installed, because the System Role installs rsyslog when deployed.

Procedure

  1. Create a playbook that defines the required role:

    1. Create a new YAML file and open it in a text editor, for example:

      # vi logging-playbook.yml
    2. Insert the following content:

      ---
      - name: Deploying basics input and implicit files output
        hosts: all
        roles:
          - rhel-system-roles.logging
        vars:
          logging_inputs:
            - name: system_input
              type: basics
          logging_outputs:
            - name: files_output
              type: files
          logging_flows:
            - name: flow1
              inputs: [system_input]
              outputs: [files_output]
  2. Run the playbook on a specific inventory:

    # ansible-playbook -i </path/to/file/inventory.ini> </path/to/file/logging-playbook.yml>

    Where:

    • <inventory.ini> is the inventory file.
    • <logging_playbook.yml> is the playbook you use.

Verification

  1. Test the syntax of the /etc/rsyslog.conf file:

    # rsyslogd -N 1
    rsyslogd: version 8.1911.0-6.el8, config validation run...
    rsyslogd: End of config validation run. Bye.
  2. Verify that the system sends messages to the log:

    1. Send a test message:

      # logger test
    2. View the /var/log/messages log, for example:

      # cat /var/log/messages
      Aug  5 13:48:31 <hostname> root[6778]: test

      Where <hostname> is the host name of the client system. Note that the log contains the user name of the user that entered the logger command, in this case root.

13.4. Filtering logs in a local logging System Role

You can deploy a logging solution which filters the logs based on the rsyslog property-based filter.

Prerequisites

  • Access and permissions to one or more managed nodes, which are systems you want to configure with the logging System Role.
  • Access and permissions to a control node, which is a system from which Red Hat Ansible Core configures other systems.

    On the control node:

    • Red Hat Ansible Core is installed
    • The rhel-system-roles package is installed
    • An inventory file which lists the managed nodes.
Note

You do not have to have the rsyslog package installed, because the System Role installs rsyslog when deployed.

Procedure

  1. Create a new playbook.yml file with the following content:

    ---
    - name: Deploying files input and configured files output
      hosts: all
      roles:
        - linux-system-roles.logging
      vars:
        logging_inputs:
          - name: files_input
            type: basics
        logging_outputs:
          - name: files_output0
            type: files
            property: msg
            property_op: contains
            property_value: error
            path: /var/log/errors.log
          - name: files_output1
            type: files
            property: msg
            property_op: "!contains"
            property_value: error
            path: /var/log/others.log
        logging_flows:
          - name: flow0
            inputs: [files_input]
            outputs: [files_output0, files_output1]

    Using this configuration, all messages that contain the error string are logged in /var/log/errors.log, and all other messages are logged in /var/log/others.log.

    You can replace the error property value with the string by which you want to filter.

    You can modify the variables according to your preferences.

  2. Optional: Verify playbook syntax:

    # ansible-playbook --syntax-check playbook.yml
  3. Run the playbook on your inventory file:

    # ansible-playbook -i inventory_file /path/to/file/playbook.yml

Verification

  1. Test the syntax of the /etc/rsyslog.conf file:

    # rsyslogd -N 1
    rsyslogd: version 8.1911.0-6.el8, config validation run...
    rsyslogd: End of config validation run. Bye.
  2. Verify that the system sends messages that contain the error string to the log:

    1. Send a test message:

      # logger error
    2. View the /var/log/errors.log log, for example:

      # cat /var/log/errors.log
      Aug  5 13:48:31 hostname root[6778]: error

      Where hostname is the host name of the client system. Note that the log contains the user name of the user that entered the logger command, in this case root.

Additional resources

  • Documentation installed with the rhel-system-roles package in /usr/share/ansible/roles/rhel-system-roles.logging/README.html

13.5. Applying a remote logging solution using the logging System Role

Follow these steps to prepare and apply a Red Hat Ansible Core playbook to configure a remote logging solution. In this playbook, one or more clients take logs from systemd-journal and forward them to a remote server. The server receives remote input from remote_rsyslog and remote_files and outputs the logs to local files in directories named by remote host names.

Prerequisites

  • Access and permissions to one or more managed nodes, which are systems you want to configure with the logging System Role.
  • Access and permissions to a control node, which is a system from which Red Hat Ansible Core configures other systems.

    On the control node:

    • The ansible-core and rhel-system-roles packages are installed.
    • An inventory file which lists the managed nodes.
Note

You do not have to have the rsyslog package installed, because the System Role installs rsyslog when deployed.

Procedure

  1. Create a playbook that defines the required role:

    1. Create a new YAML file and open it in a text editor, for example:

      # vi logging-playbook.yml
    2. Insert the following content into the file:

      ---
      - name: Deploying remote input and remote_files output
        hosts: server
        roles:
          - rhel-system-roles.logging
        vars:
          logging_inputs:
            - name: remote_udp_input
              type: remote
              udp_ports: [ 601 ]
            - name: remote_tcp_input
              type: remote
              tcp_ports: [ 601 ]
          logging_outputs:
            - name: remote_files_output
              type: remote_files
          logging_flows:
            - name: flow_0
              inputs: [remote_udp_input, remote_tcp_input]
              outputs: [remote_files_output]
      
      - name: Deploying basics input and forwards output
        hosts: clients
        roles:
          - rhel-system-roles.logging
        vars:
          logging_inputs:
            - name: basic_input
              type: basics
          logging_outputs:
            - name: forward_output0
              type: forwards
              severity: info
              target: <host1.example.com>
              udp_port: 601
            - name: forward_output1
              type: forwards
              facility: mail
              target: <host1.example.com>
              tcp_port: 601
          logging_flows:
            - name: flows0
              inputs: [basic_input]
              outputs: [forward_output0, forward_output1]
      
      [basic_input]
      [forward_output0, forward_output1]

      Where <host1.example.com> is the logging server.

      Note

      You can modify the parameters in the playbook to fit your needs.

      Warning

      The logging solution works only with the ports defined in the SELinux policy of the server or client system and open in the firewall. The default SELinux policy includes ports 601, 514, 6514, 10514, and 20514. To use a different port, modify the SELinux policy on the client and server systems.

  2. Create an inventory file that lists your servers and clients:

    1. Create a new file and open it in a text editor, for example:

      # vi <inventory.ini>
    2. Insert the following content into the inventory file:

      [servers]
      server ansible_host=<host1.example.com>
      [clients]
      client ansible_host=<host2.example.com>

      Where:

      • <host1.example.com> is the logging server.
      • <host2.example.com> is the logging client.
  3. Run the playbook on your inventory.

    # ansible-playbook -i </path/to/file/inventory.ini> </path/to/file/logging-playbook.yml>

    Where:

    • <inventory.ini>_ is the inventory file.
    • <logging-playbook.yml>_ is the playbook you created.

Verification

  1. On both the client and the server system, test the syntax of the /etc/rsyslog.conf file:

    # rsyslogd -N 1
    rsyslogd: version 8.1911.0-6.el8, config validation run (level 1), master config /etc/rsyslog.conf
    rsyslogd: End of config validation run. Bye.
  2. Verify that the client system sends messages to the server:

    1. On the client system, send a test message:

      # logger test
    2. On the server system, view the /var/log/<host2.example.com>/messages log, for example:

      # cat /var/log/<host2.example.com>/messages
      Aug  5 13:48:31 <host2.example.com> root[6778]: test

      Where <host2.example.com> is the host name of the client system. Note that the log contains the user name of the user that entered the logger command, in this case root.

Additional resources

13.6. Using the logging System Role with TLS

Transport Layer Security (TLS) is a cryptographic protocol designed to allow secure communication over the computer network.

As an administrator, you can use the logging RHEL System Role to configure a secure transfer of logs using Red Hat Ansible Automation Platform.

13.6.1. Configuring client logging with TLS

You can use an Ansible playbook with the logging System Role to configure logging on RHEL clients and transfer logs to a remote logging system using TLS encryption.

This procedure creates a private key and certificate, and configures TLS on all hosts in the clients group in the Ansible inventory. The TLS protocol encrypts the message transmission for secure transfer of logs over the network.

Note

You do not have to call the certificate System Role in the playbook to create the certificate. The logging System Role calls it automatically.

In order for the CA to be able to sign the created certificate, the managed nodes must be enrolled in an IdM domain.

Prerequisites

  • You have permissions to run playbooks on managed nodes on which you want to configure TLS.
  • The managed nodes are listed in the inventory file on the control node.
  • The ansible and rhel-system-roles packages are installed on the control node.
  • The managed nodes are enrolled in an IdM domain.

Procedure

  1. Create a playbook.yml file with the following content:

    ---
    - name: Deploying files input and forwards output with certs
      hosts: clients
      roles:
        - rhel-system-roles.logging
      vars:
        logging_certificates:
          - name: logging_cert
            dns: ['localhost', 'www.example.com']
            ca: ipa
        logging_pki_files:
          - ca_cert: /local/path/to/ca_cert.pem
            cert: /local/path/to/logging_cert.pem
            private_key: /local/path/to/logging_cert.pem
        logging_inputs:
          - name: input_name
            type: files
            input_log_path: /var/log/containers/*.log
        logging_outputs:
          - name: output_name
            type: forwards
            target: your_target_host
            tcp_port: 514
            tls: true
            pki_authmode: x509/name
            permitted_server: 'server.example.com'
        logging_flows:
          - name: flow_name
            inputs: [input_name]
            outputs: [output_name]

    The playbook uses the following parameters:

    logging_certificates
    The value of this parameter is passed on to certificate_requests in the certificate role and used to create a private key and certificate.
    logging_pki_files

    Using this parameter, you can configure the paths and other settings that logging uses to find the CA, certificate, and key files used for TLS, specified with one or more of the following sub-parameters: ca_cert, ca_cert_src, cert, cert_src, private_key, private_key_src, and tls.

    Note

    If you are using logging_certificates to create the files on the target node, do not use ca_cert_src, cert_src, and private_key_src, which are used to copy files not created by logging_certificates.

    ca_cert
    Represents the path to the CA certificate file on the target node. Default path is /etc/pki/tls/certs/ca.pem and the file name is set by the user.
    cert
    Represents the path to the certificate file on the target node. Default path is /etc/pki/tls/certs/server-cert.pem and the file name is set by the user.
    private_key
    Represents the path to the private key file on the target node. Default path is /etc/pki/tls/private/server-key.pem and the file name is set by the user.
    ca_cert_src
    Represents the path to the CA certificate file on the control node which is copied to the target host to the location specified by ca_cert. Do not use this if using logging_certificates.
    cert_src
    Represents the path to a certificate file on the control node which is copied to the target host to the location specified by cert. Do not use this if using logging_certificates.
    private_key_src
    Represents the path to a private key file on the control node which is copied to the target host to the location specified by private_key. Do not use this if using logging_certificates.
    tls
    Setting this parameter to true ensures secure transfer of logs over the network. If you do not want a secure wrapper, you can set tls: false.
  2. Verify playbook syntax:

    # ansible-playbook --syntax-check playbook.yml
  3. Run the playbook on your inventory file:

    # ansible-playbook -i inventory_file playbook.yml

13.6.2. Configuring server logging with TLS

You can use an Ansible playbook with the logging System Role to configure logging on RHEL servers and set them to receive logs from a remote logging system using TLS encryption.

This procedure creates a private key and certificate, and configures TLS on all hosts in the server group in the Ansible inventory.

Note

You do not have to call the certificate System Role in the playbook to create the certificate. The logging System Role calls it automatically.

In order for the CA to be able to sign the created certificate, the managed nodes must be enrolled in an IdM domain.

Prerequisites

  • You have permissions to run playbooks on managed nodes on which you want to configure TLS.
  • The managed nodes are listed in the inventory file on the control node.
  • The ansible and rhel-system-roles packages are installed on the control node.
  • The managed nodes are enrolled in an IdM domain.

Procedure

  1. Create a playbook.yml file with the following content:

    ---
    - name: Deploying remote input and remote_files output with certs
      hosts: server
      roles:
        - rhel-system-roles.logging
      vars:
        logging_certificates:
          - name: logging_cert
            dns: ['localhost', 'www.example.com']
            ca: ipa
        logging_pki_files:
          - ca_cert: /local/path/to/ca_cert.pem
            cert: /local/path/to/logging_cert.pem
            private_key: /local/path/to/logging_cert.pem
        logging_inputs:
          - name: input_name
            type: remote
            tcp_ports: 514
            tls: true
            permitted_clients: ['clients.example.com']
        logging_outputs:
          - name: output_name
            type: remote_files
            remote_log_path: /var/log/remote/%FROMHOST%/%PROGRAMNAME:::secpath-replace%.log
            async_writing: true
            client_count: 20
            io_buffer_size: 8192
        logging_flows:
          - name: flow_name
            inputs: [input_name]
            outputs: [output_name]

    The playbook uses the following parameters:

    logging_certificates
    The value of this parameter is passed on to certificate_requests in the certificate role and used to create a private key and certificate.
    logging_pki_files

    Using this parameter, you can configure the paths and other settings that logging uses to find the CA, certificate, and key files used for TLS, specified with one or more of the following sub-parameters: ca_cert, ca_cert_src, cert, cert_src, private_key, private_key_src, and tls.

    Note

    If you are using logging_certificates to create the files on the target node, do not use ca_cert_src, cert_src, and private_key_src, which are used to copy files not created by logging_certificates.

    ca_cert
    Represents the path to the CA certificate file on the target node. Default path is /etc/pki/tls/certs/ca.pem and the file name is set by the user.
    cert
    Represents the path to the certificate file on the target node. Default path is /etc/pki/tls/certs/server-cert.pem and the file name is set by the user.
    private_key
    Represents the path to the private key file on the target node. Default path is /etc/pki/tls/private/server-key.pem and the file name is set by the user.
    ca_cert_src
    Represents the path to the CA certificate file on the control node which is copied to the target host to the location specified by ca_cert. Do not use this if using logging_certificates.
    cert_src
    Represents the path to a certificate file on the control node which is copied to the target host to the location specified by cert. Do not use this if using logging_certificates.
    private_key_src
    Represents the path to a private key file on the control node which is copied to the target host to the location specified by private_key. Do not use this if using logging_certificates.
    tls
    Setting this parameter to true ensures secure transfer of logs over the network. If you do not want a secure wrapper, you can set tls: false.
  2. Verify playbook syntax:

    # ansible-playbook --syntax-check playbook.yml
  3. Run the playbook on your inventory file:

    # ansible-playbook -i inventory_file playbook.yml

13.7. Using the logging System Roles with RELP

Reliable Event Logging Protocol (RELP) is a networking protocol for data and message logging over the TCP network. It ensures reliable delivery of event messages and you can use it in environments that do not tolerate any message loss.

The RELP sender transfers log entries in form of commands and the receiver acknowledges them once they are processed. To ensure consistency, RELP stores the transaction number to each transferred command for any kind of message recovery.

You can consider a remote logging system in between the RELP Client and RELP Server. The RELP Client transfers the logs to the remote logging system and the RELP Server receives all the logs sent by the remote logging system.

Administrators can use the logging System Role to configure the logging system to reliably send and receive log entries.

13.7.1. Configuring client logging with RELP

You can use the logging System Role to configure logging in RHEL systems that are logged on a local machine and can transfer logs to the remote logging system with RELP by running an Ansible playbook.

This procedure configures RELP on all hosts in the clients group in the Ansible inventory. The RELP configuration uses Transport Layer Security (TLS) to encrypt the message transmission for secure transfer of logs over the network.

Prerequisites

  • You have permissions to run playbooks on managed nodes on which you want to configure RELP.
  • The managed nodes are listed in the inventory file on the control node.
  • The ansible and rhel-system-roles packages are installed on the control node.

Procedure

  1. Create a playbook.yml file with the following content:

    ---
    - name: Deploying basic input and relp output
      hosts: clients
      roles:
        - rhel-system-roles.logging
      vars:
        logging_inputs:
          - name: basic_input
            type: basics
        logging_outputs:
          - name: relp_client
            type: relp
            target: logging.server.com
            port: 20514
            tls: true
            ca_cert: /etc/pki/tls/certs/ca.pem
            cert: /etc/pki/tls/certs/client-cert.pem
            private_key: /etc/pki/tls/private/client-key.pem
            pki_authmode: name
            permitted_servers:
              - '*.server.example.com'
        logging_flows:
          - name: example_flow
            inputs: [basic_input]
            outputs: [relp_client]

    The playbooks uses following settings:

    • target: This is a required parameter that specifies the host name where the remote logging system is running.
    • port: Port number the remote logging system is listening.
    • tls: Ensures secure transfer of logs over the network. If you do not want a secure wrapper you can set the tls variable to false. By default tls parameter is set to true while working with RELP and requires key/certificates and triplets {ca_cert, cert, private_key} and/or {ca_cert_src, cert_src, private_key_src}.

      • If the {ca_cert_src, cert_src, private_key_src} triplet is set, the default locations /etc/pki/tls/certs and /etc/pki/tls/private are used as the destination on the managed node to transfer files from control node. In this case, the file names are identical to the original ones in the triplet
      • If the {ca_cert, cert, private_key} triplet is set, files are expected to be on the default path before the logging configuration.
      • If both triplets are set, files are transferred from local path from control node to specific path of the managed node.
    • ca_cert: Represents the path to CA certificate. Default path is /etc/pki/tls/certs/ca.pem and the file name is set by the user.
    • cert: Represents the path to certificate. Default path is /etc/pki/tls/certs/server-cert.pem and the file name is set by the user.
    • private_key: Represents the path to private key. Default path is /etc/pki/tls/private/server-key.pem and the file name is set by the user.
    • ca_cert_src: Represents local CA certificate file path which is copied to the target host. If ca_cert is specified, it is copied to the location.
    • cert_src: Represents the local certificate file path which is copied to the target host. If cert is specified, it is copied to the location.
    • private_key_src: Represents the local key file path which is copied to the target host. If private_key is specified, it is copied to the location.
    • pki_authmode: Accepts the authentication mode as name or fingerprint.
    • permitted_servers: List of servers that will be allowed by the logging client to connect and send logs over TLS.
    • inputs: List of logging input dictionary.
    • outputs: List of logging output dictionary.
  2. Optional: Verify playbook syntax.

    # ansible-playbook --syntax-check playbook.yml
  3. Run the playbook:

    # ansible-playbook -i inventory_file playbook.yml

13.7.2. Configuring server logging with RELP

You can use the logging System Role to configure logging in RHEL systems as a server and can receive logs from the remote logging system with RELP by running an Ansible playbook.

This procedure configures RELP on all hosts in the server group in the Ansible inventory. The RELP configuration uses TLS to encrypt the message transmission for secure transfer of logs over the network.

Prerequisites

  • You have permissions to run playbooks on managed nodes on which you want to configure RELP.
  • The managed nodes are listed in the inventory file on the control node.
  • The ansible and rhel-system-roles packages are installed on the control node.

Procedure

  1. Create a playbook.yml file with the following content:

    ---
    - name: Deploying remote input and remote_files output
      hosts: server
      roles:
        - rhel-system-roles.logging
      vars:
        logging_inputs:
          - name: relp_server
            type: relp
            port: 20514
            tls: true
            ca_cert: /etc/pki/tls/certs/ca.pem
            cert: /etc/pki/tls/certs/server-cert.pem
            private_key: /etc/pki/tls/private/server-key.pem
            pki_authmode: name
            permitted_clients:
              - '*example.client.com'
        logging_outputs:
          - name: remote_files_output
            type: remote_files
        logging_flows:
          - name: example_flow
            inputs: relp_server
            outputs: remote_files_output

    The playbooks uses the following settings:

    • port: Port number the remote logging system is listening.
    • tls: Ensures secure transfer of logs over the network. If you do not want a secure wrapper you can set the tls variable to false. By default tls parameter is set to true while working with RELP and requires key/certificates and triplets {ca_cert, cert, private_key} and/or {ca_cert_src, cert_src, private_key_src}.

      • If the {ca_cert_src, cert_src, private_key_src} triplet is set, the default locations /etc/pki/tls/certs and /etc/pki/tls/private are used as the destination on the managed node to transfer files from control node. In this case, the file names are identical to the original ones in the triplet
      • If the {ca_cert, cert, private_key} triplet is set, files are expected to be on the default path before the logging configuration.
      • If both triplets are set, files are transferred from local path from control node to specific path of the managed node.
    • ca_cert: Represents the path to CA certificate. Default path is /etc/pki/tls/certs/ca.pem and the file name is set by the user.
    • cert: Represents the path to the certificate. Default path is /etc/pki/tls/certs/server-cert.pem and the file name is set by the user.
    • private_key: Represents the path to private key. Default path is /etc/pki/tls/private/server-key.pem and the file name is set by the user.
    • ca_cert_src: Represents local CA certificate file path which is copied to the target host. If ca_cert is specified, it is copied to the location.
    • cert_src: Represents the local certificate file path which is copied to the target host. If cert is specified, it is copied to the location.
    • private_key_src: Represents the local key file path which is copied to the target host. If private_key is specified, it is copied to the location.
    • pki_authmode: Accepts the authentication mode as name or fingerprint.
    • permitted_clients: List of clients that will be allowed by the logging server to connect and send logs over TLS.
    • inputs: List of logging input dictionary.
    • outputs: List of logging output dictionary.
  2. Optional: Verify playbook syntax.

    # ansible-playbook --syntax-check playbook.yml
  3. Run the playbook:

    # ansible-playbook -i inventory_file playbook.yml

13.8. Additional resources

Chapter 14. Configuring the systemd journal by using the journald RHEL System Role

With the journald System Role you can automate the systemd journal, and configure persistent logging by using the Red Hat Ansible Automation Platform.

14.1. Variables for the journald RHEL System Role

The journald System Role provides a set of variables for customizing the behavior of journald logging service. The role includes the following variables:

Role VariableDescription

journald_persistent

Use this boolean variable to configure journald for storing log files on disk in the /var/log/journal/ directory. When you set this variable to true, logs are stored on disk, otherwise, they are stored in volatile memory. The default value is false.

journald_max_disk_size

Use this variable to specify the maximum size, in megabytes, that journal files can occupy on disk. Refer to the default sizing calculation described in journald.conf(5) man page.

journald_max_files

Use this variable to specify the maximum number of journal files you want to keep while respecting the journal_max_disk_size setting for journal.

journald_max_file_size

Use this variable to specify the maximum size, in megabytes, of a single journal file.

journald_per_user

Use this boolean variable to configure journald for keeping log data separate for each user. The default value is true and the unprivileged users can read system logs from their own user services. Note that per-user journal files are only available when the journald_persistent variable is set to true.

journald_compression

Use this boolean variable to apply compression to journald data objects that are larger than the default 512 bytes. The default value is true.

journald_sync_interval

Use this variable to specify the time, in minutes, after which journald synchronizes the currently used journal file to disk. By default, the role does not alter the current value.

Additional resources

  • The journald.conf(5) man page.

14.2. Configuring persistent logging by using the journald System Role

As a system administrator, you can configure persistent logging by using the journald System Role. The following example shows how to set up the journald System Role variables in a playbook to achieve the following goals:

  • Configuring persistent logging
  • Specifying the maximum size of disk space for journal files
  • Configuring journald to keep log data separate for each user
  • Defining the synchronization interval

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The managed nodes or groups of managed nodes on which you want to run this playbook are listed in the Ansible inventory file.

Procedure

  1. Create a new playbook.yml file with the following content:

    ---
    - hosts: all
      vars:
        journald_persistent: true
        journald_max_disk_size: 2048
        journald_per_user: true
        journald_sync_interval: 1
      roles:
        - linux-system-roles.journald
    ---

    As a result, the journald service stores your logs persistently on a disk to the maximum size of 2048 MB, and keeps log data separate for each user. The synchronization happens every minute.

  2. Optional: Verify playbook syntax.

    # ansible-playbook --syntax-check playbook.yml -i inventory_file
  3. Run the playbook on your inventory file:

    # ansible-playbook -i inventory_file /path/to/file/playbook.yml

14.3. Additional resources

  • The journald.conf(5) man page
  • The ansible-playbook(1) man page

Chapter 15. Configuring secure communication by using the ssh and sshd RHEL System Roles

As an administrator, you can use the sshd System Role to configure SSH servers and the ssh System Role to configure SSH clients consistently on any number of RHEL systems at the same time by using Red Hat Ansible Automation Platform.

15.1. ssh Server System Role variables

In an sshd System Role playbook, you can define the parameters for the SSH configuration file according to your preferences and limitations.

If you do not configure these variables, the System Role produces an sshd_config file that matches the RHEL defaults.

In all cases, Booleans correctly render as yes and no in sshd configuration. You can define multi-line configuration items using lists. For example:

sshd_ListenAddress:
  - 0.0.0.0
  - '::'

renders as:

ListenAddress 0.0.0.0
ListenAddress ::

Variables for the sshd System Role

sshd_enable
If set to false, the role is completely disabled. Defaults to true.
sshd_skip_defaults
If set to true, the System Role does not apply default values. Instead, you specify the complete set of configuration defaults by using either the sshd dictionary or sshd_<OptionName> variables. Defaults to false.
sshd_manage_service
If set to false, the service is not managed, which means it is not enabled on boot and does not start or reload. Defaults to true except when running inside a container or AIX, because the Ansible service module does not currently support enabled for AIX.
sshd_allow_reload
If set to false, sshd does not reload after a change of configuration. This can help with troubleshooting. To apply the changed configuration, reload sshd manually. Defaults to the same value as sshd_manage_service except on AIX, where sshd_manage_service defaults to false but sshd_allow_reload defaults to true.
sshd_install_service

If set to true, the role installs service files for the sshd service. This overrides files provided in the operating system. Do not set to true unless you are configuring a second instance and you also change the sshd_service variable. Defaults to false.

The role uses the files pointed by the following variables as templates:

sshd_service_template_service (default: templates/sshd.service.j2)
sshd_service_template_at_service (default: templates/sshd@.service.j2)
sshd_service_template_socket (default: templates/sshd.socket.j2)
sshd_service
This variable changes the sshd service name, which is useful for configuring a second sshd service instance.
sshd

A dictionary that contains configuration. For example:

sshd:
  Compression: yes
  ListenAddress:
    - 0.0.0.0

The sshd_config(5) lists all options for the sshd dictionary.

sshd_<OptionName>

You can define options by using simple variables consisting of the sshd_ prefix and the option name instead of a dictionary. The simple variables override values in the sshd dictionary. For example:

sshd_Compression: no

The sshd_config(5) lists all options for sshd.

sshd_manage_firewall

Set this variable to true if you are using a different port than the default port 22. When set to true, the sshd role uses the firewall role to automatically manage port access.

Note

The sshd_manage_firewall variable can only add ports. It cannot remove ports. To remove ports, use the firewall System Role directly. For more information about managing ports by using the firewall System Role, see Configuring ports by using System Roles.

sshd_manage_selinux

Set this variable to true if you are using a different port than the default port 22. When set to true, the sshd role uses the selinux role to automatically manage port access.

Note

The sshd_manage_selinux variable can only add ports. It cannot remove ports. To remove ports, use the selinux System Role directly.

sshd_match and sshd_match_1 to sshd_match_9
A list of dictionaries or just a dictionary for a Match section. Note that these variables do not override match blocks as defined in the sshd dictionary. All of the sources will be reflected in the resulting configuration file.
sshd_backup
When set to false, the original sshd_config file is not backed up. Default is true.

Secondary variables for the sshd System Role

You can use these variables to override the defaults that correspond to each supported platform.

sshd_packages
You can override the default list of installed packages using this variable.
sshd_config_owner, sshd_config_group, and sshd_config_mode
You can set the ownership and permissions for the openssh configuration file that this role produces using these variables.
sshd_config_file
The path where this role saves the openssh server configuration produced.
sshd_config_namespace

The default value of this variable is null, which means that the role defines the entire content of the configuration file including system defaults. Alternatively, you can use this variable to invoke this role from other roles or from multiple places in a single playbook on systems that do not support drop-in directory. The sshd_skip_defaults variable is ignored and no system defaults are used in this case.

When this variable is set, the role places the configuration that you specify to configuration snippets in an existing configuration file under the given namespace. If your scenario requires applying the role several times, you need to select a different namespace for each application.

Note

Limitations of the openssh configuration file still apply. For example, only the first option specified in a configuration file is effective for most of the configuration options.

Technically, the role places snippets in "Match all" blocks, unless they contain other match blocks, to ensure they are applied regardless of the previous match blocks in the existing configuration file. This allows configuring any non-conflicting options from different roles invocations.

sshd_binary
The path to the sshd executable of openssh.
sshd_service
The name of the sshd service. By default, this variable contains the name of the sshd service that the target platform uses. You can also use it to set the name of the custom sshd service when the role uses the sshd_install_service variable.
sshd_verify_hostkeys
Defaults to auto. When set to auto, this lists all host keys that are present in the produced configuration file, and generates any paths that are not present. Additionally, permissions and file owners are set to default values. This is useful if the role is used in the deployment stage to verify the service is able to start on the first attempt. To disable this check, set this variable to an empty list [].
sshd_hostkey_owner, sshd_hostkey_group, sshd_hostkey_mode
Use these variables to set the ownership and permissions for the host keys from sshd_verify_hostkeys.
sshd_sysconfig
On systems based on RHEL 8 and earlier versions, this variable configures additional details of the sshd service. If set to true, this role manages also the /etc/sysconfig/sshd configuration file based on the sshd_sysconfig_override_crypto_policy and sshd_sysconfig_use_strong_rng variables. Defaults to false.
sshd_sysconfig_override_crypto_policy

In RHEL 8, setting it to true allows overriding the system-wide cryptographic policy by using the following configuration options in the sshd dictionary or in the sshd_<OptionName> format:

  • Ciphers
  • MACs
  • GSSAPIKexAlgorithms
  • GSSAPIKeyExchange (FIPS-only)
  • KexAlgorithms
  • HostKeyAlgorithms
  • PubkeyAcceptedKeyTypes
  • CASignatureAlgorithms

    Defaults to false.

    In RHEL 9, this variable has no effect. Instead, you can override system-wide cryptographic policies by using the following configuration options in the sshd dictionary or in the sshd_<OptionName> format:

  • Ciphers
  • MACs
  • GSSAPIKexAlgorithms
  • GSSAPIKeyExchange (FIPS-only)
  • KexAlgorithms
  • HostKeyAlgorithms
  • PubkeyAcceptedAlgorithms
  • HostbasedAcceptedAlgorithms
  • CASignatureAlgorithms
  • RequiredRSASize

    If you enter these options into custom configuration files in the drop-in directory defined in the sshd_config_file variable, use a file name that lexicographically precedes the /etc/ssh/sshd_config.d/50-redhat.conf file that includes the cryptographic policies.

sshd_sysconfig_use_strong_rng
On systems based on RHEL 8 and earlier versions, this variable can force sshd to reseed the openssl random number generator with the number of bytes given as the argument. The default is 0, which disables this functionality. Do not turn this on if the system does not have a hardware random number generator.

15.2. Configuring OpenSSH servers using the sshd System Role

You can use the sshd System Role to configure multiple SSH servers by running an Ansible playbook.

Note

You can use the sshd System Role with other System Roles that change SSH and SSHD configuration, for example the Identity Management RHEL System Roles. To prevent the configuration from being overwritten, make sure that the sshd role uses namespaces (RHEL 8 and earlier versions) or a drop-in directory (RHEL 9).

Prerequisites

  • Access and permissions to one or more managed nodes, which are systems you want to configure with the sshd System Role.
  • Access and permissions to a control node, which is a system from which Red Hat Ansible Core configures other systems.

    On the control node:

    • The ansible-core and rhel-system-roles packages are installed.
Important

RHEL 8.0-8.5 provided access to a separate Ansible repository that contains Ansible Engine 2.9 for automation based on Ansible. Ansible Engine contains command-line utilities such as ansible, ansible-playbook, connectors such as docker and podman, and many plugins and modules. For information about how to obtain and install Ansible Engine, see the How to download and install Red Hat Ansible Engine Knowledgebase article.

RHEL 8.6 and 9.0 have introduced Ansible Core (provided as the ansible-core package), which contains the Ansible command-line utilities, commands, and a small set of built-in Ansible plugins. RHEL provides this package through the AppStream repository, and it has a limited scope of support. For more information, see the Scope of support for the Ansible Core package included in the RHEL 9 and RHEL 8.6 and later AppStream repositories Knowledgebase article.

  • An inventory file which lists the managed nodes.

Procedure

  1. Copy the example playbook for the sshd System Role:

    # cp /usr/share/doc/rhel-system-roles/sshd/example-root-login-playbook.yml path/custom-playbook.yml
  2. Open the copied playbook by using a text editor, for example:

    # vim path/custom-playbook.yml
    
    ---
    - hosts: all
      tasks:
      - name: Configure sshd to prevent root and password login except from particular subnet
        include_role:
          name: rhel-system-roles.sshd
        vars:
          sshd:
            # root login and password login is enabled only from a particular subnet
            PermitRootLogin: no
            PasswordAuthentication: no
            Match:
            - Condition: "Address 192.0.2.0/24"
              PermitRootLogin: yes
              PasswordAuthentication: yes

    The playbook configures the managed node as an SSH server configured so that:

    • password and root user login is disabled
    • password and root user login is enabled only from the subnet 192.0.2.0/24

    You can modify the variables according to your preferences. For more details, see sshd System Role variables.

  3. Optional: Verify playbook syntax.

    # ansible-playbook --syntax-check path/custom-playbook.yml
  4. Run the playbook on your inventory file:

    # ansible-playbook -i inventory_file path/custom-playbook.yml
    
    ...
    
    PLAY RECAP
    **************************************************
    
    localhost : ok=12 changed=2 unreachable=0 failed=0
    skipped=10 rescued=0 ignored=0

Verification

  1. Log in to the SSH server:

    $ ssh user1@10.1.1.1

    Where:

    • user1 is a user on the SSH server.
    • 10.1.1.1 is the IP address of the SSH server.
  2. Check the contents of the sshd_config file on the SSH server:

    $ cat /etc/ssh/sshd_config
    …
    PasswordAuthentication no
    PermitRootLogin no
    …
    Match Address 192.0.2.0/24
      PasswordAuthentication yes
      PermitRootLogin yes
    …
  3. Check that you can connect to the server as root from the 192.0.2.0/24 subnet:

    1. Determine your IP address:

      $ hostname -I
      192.0.2.1

      If the IP address is within the 192.0.2.1 - 192.0.2.254 range, you can connect to the server.

    2. Connect to the server as root:

      $ ssh root@10.1.1.1

Additional resources

  • /usr/share/doc/rhel-system-roles/sshd/README.md file.
  • ansible-playbook(1) man page.

15.3. ssh System Role variables

In an ssh System Role playbook, you can define the parameters for the client SSH configuration file according to your preferences and limitations.

If you do not configure these variables, the System Role produces a global ssh_config file that matches the RHEL defaults.

In all cases, booleans correctly render as yes or no in ssh configuration. You can define multi-line configuration items using lists. For example:

LocalForward:
  - 22 localhost:2222
  - 403 localhost:4003

renders as:

LocalForward 22 localhost:2222
LocalForward 403 localhost:4003
Note

The configuration options are case sensitive.

Variables for the ssh System Role

ssh_user
You can define an existing user name for which the System Role modifies user-specific configuration. The user-specific configuration is saved in ~/.ssh/config of the given user. The default value is null, which modifies global configuration for all users.
ssh_skip_defaults
Defaults to auto. If set to auto, the System Role writes the system-wide configuration file /etc/ssh/ssh_config and keeps the RHEL defaults defined there. Creating a drop-in configuration file, for example by defining the ssh_drop_in_name variable, automatically disables the ssh_skip_defaults variable.
ssh_drop_in_name

Defines the name for the drop-in configuration file, which is placed in the system-wide drop-in directory. The name is used in the template /etc/ssh/ssh_config.d/{ssh_drop_in_name}.conf to reference the configuration file to be modified. If the system does not support drop-in directory, the default value is null. If the system supports drop-in directories, the default value is 00-ansible.

Warning

If the system does not support drop-in directories, setting this option will make the play fail.

The suggested format is NN-name, where NN is a two-digit number used for ordering the configuration files and name is any descriptive name for the content or the owner of the file.

ssh
A dict that contains configuration options and their respective values.
ssh_OptionName
You can define options by using simple variables consisting of the ssh_ prefix and the option name instead of a dict. The simple variables override values in the ssh dict.
ssh_additional_packages
This role automatically installs the openssh and openssh-clients packages, which are needed for the most common use cases. If you need to install additional packages, for example, openssh-keysign for host-based authentication, you can specify them in this variable.
ssh_config_file

The path to which the role saves the configuration file produced. Default value:

  • If the system has a drop-in directory, the default value is defined by the template /etc/ssh/ssh_config.d/{ssh_drop_in_name}.conf.
  • If the system does not have a drop-in directory, the default value is /etc/ssh/ssh_config.
  • if the ssh_user variable is defined, the default value is ~/.ssh/config.
ssh_config_owner, ssh_config_group, ssh_config_mode
The owner, group and modes of the created configuration file. By default, the owner of the file is root:root, and the mode is 0644. If ssh_user is defined, the mode is 0600, and the owner and group are derived from the user name specified in the ssh_user variable.

15.4. Configuring OpenSSH clients using the ssh System Role

You can use the ssh System Role to configure multiple SSH clients by running an Ansible playbook.

Note

You can use the ssh System Role with other System Roles that change SSH and SSHD configuration, for example the Identity Management RHEL System Roles. To prevent the configuration from being overwritten, make sure that the ssh role uses a drop-in directory (default from RHEL 8).

Prerequisites

  • Access and permissions to one or more managed nodes, which are systems you want to configure with the ssh System Role.
  • Access and permissions to a control node, which is a system from which Red Hat Ansible Core configures other systems.

    On the control node:

    • The ansible-core and rhel-system-roles packages are installed.
Important

RHEL 8.0-8.5 provided access to a separate Ansible repository that contains Ansible Engine 2.9 for automation based on Ansible. Ansible Engine contains command-line utilities such as ansible, ansible-playbook, connectors such as docker and podman, and many plugins and modules. For information about how to obtain and install Ansible Engine, see the How to download and install Red Hat Ansible Engine Knowledgebase article.

RHEL 8.6 and 9.0 have introduced Ansible Core (provided as the ansible-core package), which contains the Ansible command-line utilities, commands, and a small set of built-in Ansible plugins. RHEL provides this package through the AppStream repository, and it has a limited scope of support. For more information, see the Scope of support for the Ansible Core package included in the RHEL 9 and RHEL 8.6 and later AppStream repositories Knowledgebase article.

  • An inventory file which lists the managed nodes.

Procedure

  1. Create a new playbook.yml file with the following content:

    ---
    - hosts: all
      tasks:
      - name: "Configure ssh clients"
        include_role:
          name: rhel-system-roles.ssh
        vars:
          ssh_user: root
          ssh:
            Compression: true
            GSSAPIAuthentication: no
            ControlMaster: auto
            ControlPath: ~/.ssh/.cm%C
            Host:
              - Condition: example
                Hostname: example.com
                User: user1
          ssh_ForwardX11: no

    This playbook configures the root user’s SSH client preferences on the managed nodes with the following configurations:

    • Compression is enabled.
    • ControlMaster multiplexing is set to auto.
    • The example alias for connecting to the example.com host is user1.
    • The example host alias is created, which represents a connection to the example.com host the with user1 user name.
    • X11 forwarding is disabled.

    Optionally, you can modify these variables according to your preferences. For more details, see ssh System Role variables.

  2. Optional: Verify playbook syntax.

    # ansible-playbook --syntax-check path/custom-playbook.yml
  3. Run the playbook on your inventory file:

    # ansible-playbook -i inventory_file path/custom-playbook.yml

Verification

  • Verify that the managed node has the correct configuration by opening the SSH configuration file in a text editor, for example:

    # vi ~root/.ssh/config

    After application of the example playbook shown above, the configuration file should have the following content:

    # Ansible managed
    Compression yes
    ControlMaster auto
    ControlPath ~/.ssh/.cm%C
    ForwardX11 no
    GSSAPIAuthentication no
    Host example
      Hostname example.com
      User user1

15.5. Using the sshd System Role for non-exclusive configuration

Normally, applying the sshd System Role overwrites the entire configuration. This may be problematic if you have previously adjusted the configuration, for example with a different System Role or playbook. To apply the sshd System Role for only selected configuration options while keeping other options in place, you can use the non-exclusive configuration.

In RHEL 8 and earlier, you can apply the non-exclusive configuration with a configuration snippet.

Prerequisites

  • Access and permissions to one or more managed nodes, which are systems you want to configure with the sshd System Role.
  • Access and permissions to a control node, which is a system from which Red Hat Ansible Core configures other systems.

    On the control node:

    • The ansible-core package is installed.
    • An inventory file which lists the managed nodes.
    • A playbook for a different RHEL System Role.

Procedure

  1. Add a configuration snippet with the sshd_config_namespace variable to the playbook:

    ---
    - hosts: all
      tasks:
      - name: <Configure SSHD to accept some useful environment variables>
        include_role:
          name: rhel-system-roles.sshd
        vars:
          sshd_config_namespace: <my-application>
          sshd:
            # Environment variables to accept
            AcceptEnv:
              LANG
              LS_COLORS
              EDITOR

    When you apply the playbook to the inventory, the role adds the following snippet, if not already present, to the /etc/ssh/sshd_config file.

    # BEGIN sshd system role managed block: namespace <my-application>
    Match all
      AcceptEnv LANG LS_COLORS EDITOR
    # END sshd system role managed block: namespace <my-application>

Verification

  • Optional: Verify playbook syntax.

    # ansible-playbook --syntax-check playbook.yml -i inventory_file

Additional resources

  • /usr/share/doc/rhel-system-roles/sshd/README.md file.
  • ansible-playbook(1) man page.

Chapter 16. Configuring VPN connections with IPsec by using the vpn RHEL System Role

With the vpn System Role, you can configure VPN connections on RHEL systems by using Red Hat Ansible Automation Platform. You can use it to set up host-to-host, network-to-network, VPN Remote Access Server, and mesh configurations.

For host-to-host connections, the role sets up a VPN tunnel between each pair of hosts in the list of vpn_connections using the default parameters, including generating keys as needed. Alternatively, you can configure it to create an opportunistic mesh configuration between all hosts listed. The role assumes that the names of the hosts under hosts are the same as the names of the hosts used in the Ansible inventory, and that you can use those names to configure the tunnels.

Note

The vpn RHEL System Role currently supports only Libreswan, which is an IPsec implementation, as the VPN provider.

16.1. Creating a host-to-host VPN with IPsec using the vpn System Role

You can use the vpn System Role to configure host-to-host connections by running an Ansible playbook on the control node, which will configure all the managed nodes listed in an inventory file.

Prerequisites

  • Access and permissions to one or more managed nodes, which are systems you want to configure with the vpn System Role.
  • Access and permissions to a control node, which is a system from which Red Hat Ansible Core configures other systems.

    On the control node:

    • The ansible-core and rhel-system-roles packages are installed.
Important

RHEL 8.0-8.5 provided access to a separate Ansible repository that contains Ansible Engine 2.9 for automation based on Ansible. Ansible Engine contains command-line utilities such as ansible, ansible-playbook, connectors such as docker and podman, and many plugins and modules. For information about how to obtain and install Ansible Engine, see the How to download and install Red Hat Ansible Engine Knowledgebase article.

RHEL 8.6 and 9.0 have introduced Ansible Core (provided as the ansible-core package), which contains the Ansible command-line utilities, commands, and a small set of built-in Ansible plugins. RHEL provides this package through the AppStream repository, and it has a limited scope of support. For more information, see the Scope of support for the Ansible Core package included in the RHEL 9 and RHEL 8.6 and later AppStream repositories Knowledgebase article.

  • An inventory file which lists the managed nodes.

Procedure

  1. Create a new playbook.yml file with the following content:

    - name: Host to host VPN
      hosts: managed_node1, managed_node2
      roles:
        - rhel-system-roles.vpn
      vars:
        vpn_connections:
          - hosts:
              managed_node1:
              managed_node2:
        vpn_manage_firewall: true
        vpn_manage_selinux: true

    This playbook configures the connection managed_node1-to-managed_node2 using pre-shared key authentication with keys auto-generated by the system role. Because vpn_manage_firewall and vpn_manage_selinux are both set to true, the vpn role uses the firewall and selinux roles to manage the ports used by the vpn role.

  2. Optional: Configure connections from managed hosts to external hosts that are not listed in the inventory file by adding the following section to the vpn_connections list of hosts:

        vpn_connections:
          - hosts:
              managed_node1:
              managed_node2:
              external_node:
                hostname: 192.0.2.2

    This configures two additional connections: managed_node1-to-external_node and managed_node2-to-external_node.

Note

The connections are configured only on the managed nodes and not on the external node.

  1. Optional: You can specify multiple VPN connections for the managed nodes by using additional sections within vpn_connections, for example a control plane and a data plane:

    - name: Multiple VPN
      hosts: managed_node1, managed_node2
      roles:
        - rhel-system-roles.vpn
      vars:
        vpn_connections:
          - name: control_plane_vpn
            hosts:
              managed_node1:
                hostname: 192.0.2.0 # IP for the control plane
              managed_node2:
                hostname: 192.0.2.1
          - name: data_plane_vpn
            hosts:
              managed_node1:
                hostname: 10.0.0.1 # IP for the data plane
              managed_node2:
                hostname: 10.0.0.2
  2. Optional: You can modify the variables according to your preferences. For more details, see the /usr/share/doc/rhel-system-roles/vpn/README.md file.
  3. Optional: Verify playbook syntax.

    # ansible-playbook --syntax-check /path/to/file/playbook.yml -i /path/to/file/inventory_file
  4. Run the playbook on your inventory file:

    # ansible-playbook -i /path/to/file/inventory_file /path/to/file/playbook.yml

Verification

  1. On the managed nodes, confirm that the connection is successfully loaded:

    # ipsec status | grep connection.name

    Replace connection.name with the name of the connection from this node, for example managed_node1-to-managed_node2.

Note

By default, the role generates a descriptive name for each connection it creates from the perspective of each system. For example, when creating a connection between managed_node1 and managed_node2, the descriptive name of this connection on managed_node1 is managed_node1-to-managed_node2 but on managed_node2 the connection is named managed_node2-to-managed_node1.

  1. On the managed nodes, confirm that the connection is successfully started:

    # ipsec trafficstatus | grep connection.name
  2. Optional: If a connection did not successfully load, manually add the connection by entering the following command. This will provide more specific information indicating why the connection failed to establish:

    # ipsec auto --add connection.name
    Note

    Any errors that may have occurred during the process of loading and starting the connection are reported in the logs, which can be found in /var/log/pluto.log. Because these logs are hard to parse, try to manually add the connection to obtain log messages from the standard output instead.

16.2. Creating an opportunistic mesh VPN connection with IPsec by using the vpn System Role

You can use the vpn System Role to configure an opportunistic mesh VPN connection that uses certificates for authentication by running an Ansible playbook on the control node, which will configure all the managed nodes listed in an inventory file.

Authentication with certificates is configured by defining the auth_method: cert parameter in the playbook. The vpn System Role assumes that the IPsec Network Security Services (NSS) crypto library, which is defined in the /etc/ipsec.d directory, contains the necessary certificates. By default, the node name is used as the certificate nickname. In this example, this is managed_node1. You can define different certificate names by using the cert_name attribute in your inventory.

In the following example procedure, the control node, which is the system from which you will run the Ansible playbook, shares the same classless inter-domain routing (CIDR) number as both of the managed nodes (192.0.2.0/24) and has the IP address 192.0.2.7. Therefore, the control node falls under the private policy which is automatically created for CIDR 192.0.2.0/24.

To prevent SSH connection loss during the play, a clear policy for the control node is included in the list of policies. Note that there is also an item in the policies list where the CIDR is equal to default. This is because this playbook overrides the rule from the default policy to make it private instead of private-or-clear.

Prerequisites

  • Access and permissions to one or more managed nodes, which are systems you want to configure with the vpn System Role.

    • On all the managed nodes, the NSS database in the /etc/ipsec.d directory contains all the certificates necessary for peer authentication. By default, the node name is used as the certificate nickname.
  • Access and permissions to a control node, which is a system from which Red Hat Ansible Core configures other systems.

    On the control node:

    • The ansible-core and rhel-system-roles packages are installed.
Important

RHEL 8.0-8.5 provided access to a separate Ansible repository that contains Ansible Engine 2.9 for automation based on Ansible. Ansible Engine contains command-line utilities such as ansible, ansible-playbook, connectors such as docker and podman, and many plugins and modules. For information about how to obtain and install Ansible Engine, see the How to download and install Red Hat Ansible Engine Knowledgebase article.

RHEL 8.6 and 9.0 have introduced Ansible Core (provided as the ansible-core package), which contains the Ansible command-line utilities, commands, and a small set of built-in Ansible plugins. RHEL provides this package through the AppStream repository, and it has a limited scope of support. For more information, see the Scope of support for the Ansible Core package included in the RHEL 9 and RHEL 8.6 and later AppStream repositories Knowledgebase article.

  • An inventory file which lists the managed nodes.

Procedure

  1. Create a new playbook.yml file with the following content:

    - name: Mesh VPN
      hosts: managed_node1, managed_node2, managed_node3
      roles:
        - rhel-system-roles.vpn
      vars:
        vpn_connections:
          - opportunistic: true
            auth_method: cert
            policies:
              - policy: private
                cidr: default
              - policy: private-or-clear
                cidr: 198.51.100.0/24
              - policy: private
                cidr: 192.0.2.0/24
              - policy: clear
                cidr: 192.0.2.7/32
        vpn_manage_firewall: true
        vpn_manage_selinux: true
    Note

    Because vpn_manage_firewall and vpn_manage_selinux are both set to true, the vpn role uses the firewall and selinux roles to manage the ports used by the vpn role.

  2. Optional: You can modify the variables according to your preferences. For more details, see the /usr/share/doc/rhel-system-roles/vpn/README.md file.
  3. Optional: Verify playbook syntax.

    # ansible-playbook --syntax-check playbook.yml
  4. Run the playbook on your inventory file:

    # ansible-playbook -i inventory_file /path/to/file/playbook.yml

16.3. Additional resources

  • For details about the parameters used in the vpn System Role and additional information about the role, see the /usr/share/doc/rhel-system-roles/vpn/README.md file.
  • For details about the ansible-playbook command, see the ansible-playbook(1) man page.

Chapter 17. Setting a custom cryptographic policy by using the crypto-policies RHEL System Role

As an administrator, you can use the crypto_policies RHEL System Role to quickly and consistently configure custom cryptographic policies across many different systems using the Ansible Core package.

17.1. crypto_policies System Role variables and facts

In a crypto_policies System Role playbook, you can define the parameters for the crypto_policies configuration file according to your preferences and limitations.

If you do not configure any variables, the System Role does not configure the system and only reports the facts.

Selected variables for the crypto_policies System Role

crypto_policies_policy
Determines the cryptographic policy the System Role applies to the managed nodes. For details about the different crypto policies, see System-wide cryptographic policies .
crypto_policies_reload
If set to yes, the affected services, currently the ipsec, bind, and sshd services, reload after applying a crypto policy. Defaults to yes.
crypto_policies_reboot_ok
If set to yes, and a reboot is necessary after the System Role changes the crypto policy, it sets crypto_policies_reboot_required to yes. Defaults to no.

Facts set by the crypto_policies System Role

crypto_policies_active
Lists the currently selected policy.
crypto_policies_available_policies
Lists all available policies available on the system.
crypto_policies_available_subpolicies
Lists all available subpolicies available on the system.

17.2. Setting a custom cryptographic policy using the crypto_policies System Role

You can use the crypto_policies System Role to configure a large number of managed nodes consistently from a single control node.

Prerequisites

  • Access and permissions to one or more managed nodes, which are systems you want to configure with the crypto_policies System Role.
  • Access and permissions to a control node, which is a system from which Red Hat Ansible Core configures other systems.

    On the control node:

    • The ansible-core and rhel-system-roles packages are installed.
Important

RHEL 8.0-8.5 provided access to a separate Ansible repository that contains Ansible Engine 2.9 for automation based on Ansible. Ansible Engine contains command-line utilities such as ansible, ansible-playbook, connectors such as docker and podman, and many plugins and modules. For information about how to obtain and install Ansible Engine, see the How to download and install Red Hat Ansible Engine Knowledgebase article.

RHEL 8.6 and 9.0 have introduced Ansible Core (provided as the ansible-core package), which contains the Ansible command-line utilities, commands, and a small set of built-in Ansible plugins. RHEL provides this package through the AppStream repository, and it has a limited scope of support. For more information, see the Scope of support for the Ansible Core package included in the RHEL 9 and RHEL 8.6 and later AppStream repositories Knowledgebase article.

  • An inventory file which lists the managed nodes.

Procedure

  1. Create a new playbook.yml file with the following content:

    ---
    - hosts: all
      tasks:
      - name: Configure crypto policies
        include_role:
          name: rhel-system-roles.crypto_policies
        vars:
          - crypto_policies_policy: FUTURE
          - crypto_policies_reboot_ok: true

    You can replace the FUTURE value with your preferred crypto policy, for example: DEFAULT, LEGACY, and FIPS:OSPP.

    The crypto_policies_reboot_ok: true variable causes the system to reboot after the System Role changes the cryptographic policy.

    For more details, see crypto_policies System Role variables and facts .

  2. Optional: Verify playbook syntax.

    # ansible-playbook --syntax-check playbook.yml
  3. Run the playbook on your inventory file:

    # ansible-playbook -i inventory_file playbook.yml

Verification

  1. On the control node, create another playbook named, for example, verify_playbook.yml:

    - hosts: all
      tasks:
     - name: Verify active crypto policy
       include_role:
         name: rhel-system-roles.crypto_policies
    
     - debug:
         var: crypto_policies_active

    This playbook does not change any configurations on the system, only reports the active policy on the managed nodes.

  2. Run the playbook on the same inventory file:

    # ansible-playbook -i inventory_file verify_playbook.yml
    
    TASK [debug] **************************
    ok: [host] => {
        "crypto_policies_active": "FUTURE"
    }

    The "crypto_policies_active": variable shows the policy active on the managed node.

17.3. Additional resources

Chapter 18. Configuring NBDE by using RHEL System Roles

18.1. Introduction to the nbde_client and nbde_server System Roles (Clevis and Tang)

RHEL System Roles is a collection of Ansible roles and modules that provide a consistent configuration interface to remotely manage multiple RHEL systems.

RHEL 8.3 introduced Ansible roles for automated deployments of Policy-Based Decryption (PBD) solutions using Clevis and Tang. The rhel-system-roles package contains these system roles, related examples, and also the reference documentation.

The nbde_client System Role enables you to deploy multiple Clevis clients in an automated way. Note that the nbde_client role supports only Tang bindings, and you cannot use it for TPM2 bindings at the moment.

The nbde_client role requires volumes that are already encrypted using LUKS. This role supports to bind a LUKS-encrypted volume to one or more Network-Bound (NBDE) servers - Tang servers. You can either preserve the existing volume encryption with a passphrase or remove it. After removing the passphrase, you can unlock the volume only using NBDE. This is useful when a volume is initially encrypted using a temporary key or password that you should remove after you provision the system.

If you provide both a passphrase and a key file, the role uses what you have provided first. If it does not find any of these valid, it attempts to retrieve a passphrase from an existing binding.

PBD defines a binding as a mapping of a device to a slot. This means that you can have multiple bindings for the same device. The default slot is slot 1.

The nbde_client role provides also the state variable. Use the present value for either creating a new binding or updating an existing one. Contrary to a clevis luks bind command, you can use state: present also for overwriting an existing binding in its device slot. The absent value removes a specified binding.

Using the nbde_client System Role, you can deploy and manage a Tang server as part of an automated disk encryption solution. This role supports the following features:

  • Rotating Tang keys
  • Deploying and backing up Tang keys

Additional resources

  • For a detailed reference on Network-Bound Disk Encryption (NBDE) role variables, install the rhel-system-roles package, and see the README.md and README.html files in the /usr/share/doc/rhel-system-roles/nbde_client/ and /usr/share/doc/rhel-system-roles/nbde_server/ directories.
  • For example system-roles playbooks, install the rhel-system-roles package, and see the /usr/share/ansible/roles/rhel-system-roles.nbde_server/examples/ directories.
  • For more information about RHEL System Roles, see Preparing a control node and managed nodes to use RHEL System Roles.

18.2. Using the nbde_server System Role for setting up multiple Tang servers

Follow the steps to prepare and apply an Ansible playbook containing your Tang server settings.

Prerequisites

  • Access and permissions to one or more managed nodes, which are systems you want to configure with the nbde_server System Role.
  • Access and permissions to a control node, which is a system from which Red Hat Ansible Core configures other systems.

    On the control node:

    • The ansible-core and rhel-system-roles packages are installed.
Important

RHEL 8.0-8.5 provided access to a separate Ansible repository that contains Ansible Engine 2.9 for automation based on Ansible. Ansible Engine contains command-line utilities such as ansible, ansible-playbook, connectors such as docker and podman, and many plugins and modules. For information about how to obtain and install Ansible Engine, see the How to download and install Red Hat Ansible Engine Knowledgebase article.

RHEL 8.6 and 9.0 have introduced Ansible Core (provided as the ansible-core package), which contains the Ansible command-line utilities, commands, and a small set of built-in Ansible plugins. RHEL provides this package through the AppStream repository, and it has a limited scope of support. For more information, see the Scope of support for the Ansible Core package included in the RHEL 9 and RHEL 8.6 and later AppStream repositories Knowledgebase article.

  • An inventory file which lists the managed nodes.

Procedure

  1. Prepare your playbook containing settings for Tang servers. You can either start from the scratch, or use one of the example playbooks from the /usr/share/ansible/roles/rhel-system-roles.nbde_server/examples/ directory.

    # cp /usr/share/ansible/roles/rhel-system-roles.nbde_server/examples/simple_deploy.yml ./my-tang-playbook.yml
  2. Edit the playbook in a text editor of your choice, for example:

    # vi my-tang-playbook.yml
  3. Add the required parameters. The following example playbook ensures deploying of your Tang server and a key rotation:

    ---
    - hosts: all
    
      vars:
        nbde_server_rotate_keys: yes
        nbde_server_manage_firewall: true
        nbde_server_manage_selinux: true
    
      roles:
        - rhel-system-roles.nbde_server
    Note

    Because nbde_server_manage_firewall and nbde_server_manage_selinux are both set to true, the nbde_server role uses the firewall and selinux roles to manage the ports used by the nbde_server role.

  4. Apply the finished playbook:

    # ansible-playbook -i inventory-file my-tang-playbook.yml

    Where:

    • inventory-file is the inventory file.
    • logging-playbook.yml is the playbook you use.
Important

To ensure that networking for a Tang pin is available during early boot by using the grubby tool on the systems where Clevis is installed:

# grubby --update-kernel=ALL --args="rd.neednet=1"

Additional resources

  • For more information, install the rhel-system-roles package, and see the /usr/share/doc/rhel-system-roles/nbde_server/ and usr/share/ansible/roles/rhel-system-roles.nbde_server/ directories.

18.3. Using the nbde_client System Role for setting up multiple Clevis clients

Follow the steps to prepare and apply an Ansible playbook containing your Clevis client settings.

Note

The nbde_client System Role supports only Tang bindings. This means that you cannot use it for TPM2 bindings at the moment.

Prerequisites

  • Access and permissions to one or more managed nodes, which are systems you want to configure with the nbde_client System Role.
  • Access and permissions to a control node, which is a system from which Red Hat Ansible Core configures other systems.
  • The Ansible Core package is installed on the control machine.
  • The rhel-system-roles package is installed on the system from which you want to run the playbook.

Procedure

  1. Prepare your playbook containing settings for Clevis clients. You can either start from the scratch, or use one of the example playbooks from the /usr/share/ansible/roles/rhel-system-roles.nbde_client/examples/ directory.

    # cp /usr/share/ansible/roles/rhel-system-roles.nbde_client/examples/high_availability.yml ./my-clevis-playbook.yml
  2. Edit the playbook in a text editor of your choice, for example:

    # vi my-clevis-playbook.yml
  3. Add the required parameters. The following example playbook configures Clevis clients for automated unlocking of two LUKS-encrypted volumes by when at least one of two Tang servers is available:

    ---
    - hosts: all
    
      vars:
        nbde_client_bindings:
          - device: /dev/rhel/root
            encryption_key_src: /etc/luks/keyfile
            servers:
              - http://server1.example.com
              - http://server2.example.com
          - device: /dev/rhel/swap
            encryption_key_src: /etc/luks/keyfile
            servers:
              - http://server1.example.com
              - http://server2.example.com
    
      roles:
        - rhel-system-roles.nbde_client
  4. Apply the finished playbook:

    # ansible-playbook -i host1,host2,host3 my-clevis-playbook.yml
Important

To ensure that networking for a Tang pin is available during early boot by using the grubby tool on the system where Clevis is installed:

# grubby --update-kernel=ALL --args="rd.neednet=1"

Additional resources

  • For details about the parameters and additional information about the NBDE Client System Role, install the rhel-system-roles package, and see the /usr/share/doc/rhel-system-roles/nbde_client/ and /usr/share/ansible/roles/rhel-system-roles.nbde_client/ directories.

Chapter 19. Requesting certificates using RHEL System Roles

With the certificate System Role, you can use Red Hat Ansible Core to issue and manage certificates.

This chapter covers the following topics:

19.1. The certificate System Role

Using the certificate System Role, you can manage issuing and renewing TLS and SSL certificates using Ansible Core.

The role uses certmonger as the certificate provider, and currently supports issuing and renewing self-signed certificates and using the IdM integrated certificate authority (CA).

You can use the following variables in your Ansible playbook with the certificate System Role:

certificate_wait
to specify if the task should wait for the certificate to be issued.
certificate_requests
to represent each certificate to be issued and its parameters.

Additional resources

19.2. Requesting a new self-signed certificate using the certificate System Role

With the certificate System Role, you can use Ansible Core to issue self-signed certificates.

This process uses the certmonger provider and requests the certificate through the getcert command.

Note

By default, certmonger automatically tries to renew the certificate before it expires. You can disable this by setting the auto_renew parameter in the Ansible playbook to no.

Prerequisites

  • The Ansible Core package is installed on the control machine.
  • You have the rhel-system-roles package installed on the system from which you want to run the playbook.

Procedure

  1. Optional: Create an inventory file, for example inventory.file:

    $ *touch inventory.file*
  2. Open your inventory file and define the hosts on which you want to request the certificate, for example:

    [webserver]
    server.idm.example.com
  3. Create a playbook file, for example request-certificate.yml:

    • Set hosts to include the hosts on which you want to request the certificate, such as webserver.
    • Set the certificate_requests variable to include the following:

      • Set the name parameter to the desired name of the certificate, such as mycert.
      • Set the dns parameter to the domain to be included in the certificate, such as *.example.com.
      • Set the ca parameter to self-sign.
    • Set the rhel-system-roles.certificate role under roles.

      This is the playbook file for this example:

      ---
      - hosts: webserver
      
        vars:
          certificate_requests:
            - name: mycert
              dns: "*.example.com"
              ca: self-sign
      
        roles:
          - rhel-system-roles.certificate
  4. Save the file.
  5. Run the playbook:

    $ *ansible-playbook -i inventory.file request-certificate.yml*

Additional resources

  • See the /usr/share/ansible/roles/rhel-system-roles.certificate/README.md file.
  • See the ansible-playbook(1) man page.

19.3. Requesting a new certificate from IdM CA using the certificate System Role

With the certificate System Role, you can use anible-core to issue certificates while using an IdM server with an integrated certificate authority (CA). Therefore, you can efficiently and consistently manage the certificate trust chain for multiple systems when using IdM as the CA.

This process uses the certmonger provider and requests the certificate through the getcert command.

Note

By default, certmonger automatically tries to renew the certificate before it expires. You can disable this by setting the auto_renew parameter in the Ansible playbook to no.

Prerequisites

  • The Ansible Core package is installed on the control machine.
  • You have the rhel-system-roles package installed on the system from which you want to run the playbook.

Procedure

  1. Optional: Create an inventory file, for example inventory.file:

    $ *touch inventory.file*
  2. Open your inventory file and define the hosts on which you want to request the certificate, for example:

    [webserver]
    server.idm.example.com
  3. Create a playbook file, for example request-certificate.yml:

    • Set hosts to include the hosts on which you want to request the certificate, such as webserver.
    • Set the certificate_requests variable to include the following:

      • Set the name parameter to the desired name of the certificate, such as mycert.
      • Set the dns parameter to the domain to be included in the certificate, such as www.example.com.
      • Set the principal parameter to specify the Kerberos principal, such as HTTP/www.example.com@EXAMPLE.COM.
      • Set the ca parameter to ipa.
    • Set the rhel-system-roles.certificate role under roles.

      This is the playbook file for this example:

      ---
      - hosts: webserver
        vars:
          certificate_requests:
            - name: mycert
              dns: www.example.com
              principal: HTTP/www.example.com@EXAMPLE.COM
              ca: ipa
      
        roles:
          - rhel-system-roles.certificate
  4. Save the file.
  5. Run the playbook:

    $ *ansible-playbook -i inventory.file request-certificate.yml*

Additional resources

  • See the /usr/share/ansible/roles/rhel-system-roles.certificate/README.md file.
  • See the ansible-playbook(1) man page.

19.4. Specifying commands to run before or after certificate issuance using the certificate System Role

With the certificate Role, you can use Ansible Core to execute a command before and after a certificate is issued or renewed.

In the following example, the administrator ensures stopping the httpd service before a self-signed certificate for www.example.com is issued or renewed, and restarting it afterwards.

Note

By default, certmonger automatically tries to renew the certificate before it expires. You can disable this by setting the auto_renew parameter in the Ansible playbook to no.

Prerequisites

  • The Ansible Core package is installed on the control machine.
  • You have the rhel-system-roles package installed on the system from which you want to run the playbook.

Procedure

  1. Optional: Create an inventory file, for example inventory.file:

    $ *touch inventory.file*
  2. Open your inventory file and define the hosts on which you want to request the certificate, for example:

    [webserver]
    server.idm.example.com
  3. Create a playbook file, for example request-certificate.yml:

    • Set hosts to include the hosts on which you want to request the certificate, such as webserver.
    • Set the certificate_requests variable to include the following:

      • Set the name parameter to the desired name of the certificate, such as mycert.
      • Set the dns parameter to the domain to be included in the certificate, such as www.example.com.
      • Set the ca parameter to the CA you want to use to issue the certificate, such as self-sign.
      • Set the run_before parameter to the command you want to execute before this certificate is issued or renewed, such as systemctl stop httpd.service.
      • Set the run_after parameter to the command you want to execute after this certificate is issued or renewed, such as systemctl start httpd.service.
    • Set the rhel-system-roles.certificate role under roles.

      This is the playbook file for this example:

      ---
      - hosts: webserver
        vars:
          certificate_requests:
            - name: mycert
              dns: www.example.com
              ca: self-sign
              run_before: systemctl stop httpd.service
              run_after: systemctl start httpd.service
      
        roles:
          - rhel-system-roles.certificate
  4. Save the file.
  5. Run the playbook:

    $ *ansible-playbook -i inventory.file request-certificate.yml*

Additional resources

  • See the /usr/share/ansible/roles/rhel-system-roles.certificate/README.md file.
  • See the ansible-playbook(1) man page.

Chapter 20. Configuring automatic crash dumps by using the kdump RHEL System Role

To manage kdump using Ansible, you can use the kdump role, which is one of the RHEL System Roles available in RHEL 8.

Using the kdump role enables you to specify where to save the contents of the system’s memory for later analysis.

For more information about RHEL System Roles and how to apply them, see Introduction to RHEL System Roles.

20.1. The kdump RHEL System Role

The kdump System Role enables you to set basic kernel dump parameters on multiple systems.

20.2. kdump role parameters

Use the mentioned role variables to set kernel dump parameters on multiple systems for RHEL System Roles.

Role VariableDescription

kdump_target

An option to specify the target location to save the crash dump file (vmcore) to a location that is not in the root file system. If the type is raw or a filesystem, the target location points to a partition, such as device node name,label, or uuid.

kdump_path

The path to which vmcore is written. If kdump_target is not null, the path is relative to that dump target. Otherwise, it must be an absolute path in the root file system.

kdump_core_collector

A command to copy the crash dump (vmcore) file. If null, kdump uses the makedumpfile program with options that depend on the kdump_target.type.

kdump_system_action

An alternative operation to perform when kdump fails to save the core dump file (vmcore) to the primary target. The additional operations include reboot, halt, poweroff, and shell.

kdump_auto_reset_crashkernel

An option to reset the crashkernel value to a new default value. For example, reset crashkernel when kexec-tools updates the default crashkernel value to a new value or if existing kernels have the old default kernel crashkernel value.

kdump_dracut_args

An option to pass additional dracut options when rebuilding kdump initrd.

kdump_reboot_ok

An option to configure a reboot action if you run the role on a managed node that does not have sufficient memory reserved for the crash kernel, for example when the file /sys/kernel/kexec_crash_size contains 0 as the crash size, you might need to reboot the managed node to configure kdump again.

Additional resources

  • The makedumpfile(8) man page.
  • For details about the parameters used in kdump and additional information about the kdump System Role, see the /usr/share/ansible/roles/rhel-system-roles.kdump/README.md file.

20.3. Configuring kdump using RHEL System Roles

You can set basic kernel dump parameters on multiple systems using the kdump System Role by running an Ansible playbook.

Warning

The kdump role replaces the kdump configuration of the managed hosts entirely by replacing the /etc/kdump.conf file. Additionally, if the kdump role is applied, all previous kdump settings are also replaced, even if they are not specified by the role variables, by replacing the /etc/sysconfig/kdump file.

Prerequisites

  • The Ansible Core package is installed on the control machine.
  • You have the rhel-system-roles package installed on the system from which you want to run the playbook.
  • You have an inventory file which lists the systems on which you want to deploy kdump.

Procedure

  1. Create a new playbook.yml file with the following content:

    ---
    - hosts: kdump-test
      vars:
        kdump_path: /var/crash
      roles:
        - rhel-system-roles.kdump
  2. Optional: Verify playbook syntax.

    # ansible-playbook --syntax-check playbook.yml
  3. Run the playbook on your inventory file:

    # ansible-playbook -i inventory_file /path/to/file/playbook.yml

Additional resources

Chapter 21. Managing local storage using RHEL System Roles

To manage LVM and local file systems (FS) using Ansible, you can use the storage role, which is one of the RHEL System Roles available in RHEL 8.

Using the storage role enables you to automate administration of file systems on disks and logical volumes on multiple machines and across all versions of RHEL starting with RHEL 7.7.

For more information about RHEL System Roles and how to apply them, see Introduction to RHEL System Roles.

21.1. Introduction to the storage RHEL System Role

The storage role can manage:

  • File systems on disks which have not been partitioned
  • Complete LVM volume groups including their logical volumes and file systems
  • MD RAID volumes and their file systems

With the storage role, you can perform the following tasks:

  • Create a file system
  • Remove a file system
  • Mount a file system
  • Unmount a file system
  • Create LVM volume groups
  • Remove LVM volume groups
  • Create logical volumes
  • Remove logical volumes
  • Create RAID volumes
  • Remove RAID volumes
  • Create LVM volume groups with RAID
  • Remove LVM volume groups with RAID
  • Create encrypted LVM volume groups
  • Create LVM logical volumes with RAID

21.2. Parameters that identify a storage device in the storage RHEL System Role

Your storage role configuration affects only the file systems, volumes, and pools that you list in the following variables.

storage_volumes

List of file systems on all unpartitioned disks to be managed.

storage_volumes can also include raid volumes.

Partitions are currently unsupported.

storage_pools

List of pools to be managed.

Currently the only supported pool type is LVM. With LVM, pools represent volume groups (VGs). Under each pool there is a list of volumes to be managed by the role. With LVM, each volume corresponds to a logical volume (LV) with a file system.

21.3. Example Ansible playbook to create an XFS file system on a block device

The example Ansible playbook applies the storage role to create an XFS file system on a block device using the default parameters.

Warning

The storage role can create a file system only on an unpartitioned, whole disk or a logical volume (LV). It cannot create the file system on a partition.

Example 21.1. A playbook that creates XFS on /dev/sdb

---
- hosts: all
  vars:
    storage_volumes:
      - name: barefs
        type: disk
        disks:
          - sdb
        fs_type: xfs
  roles:
    - rhel-system-roles.storage
  • The volume name (barefs in the example) is currently arbitrary. The storage role identifies the volume by the disk device listed under the disks: attribute.
  • You can omit the fs_type: xfs line because XFS is the default file system in RHEL 8.
  • To create the file system on an LV, provide the LVM setup under the disks: attribute, including the enclosing volume group. For details, see Example Ansible playbook to manage logical volumes.

    Do not provide the path to the LV device.

Additional resources

  • The /usr/share/ansible/roles/rhel-system-roles.storage/README.md file.

21.4. Example Ansible playbook to persistently mount a file system

The example Ansible applies the storage role to immediately and persistently mount an XFS file system.

Example 21.2. A playbook that mounts a file system on /dev/sdb to /mnt/data

---
- hosts: all
  vars:
    storage_volumes:
      - name: barefs
        type: disk
        disks:
          - sdb
        fs_type: xfs
        mount_point: /mnt/data
  roles:
    - rhel-system-roles.storage
  • This playbook adds the file system to the /etc/fstab file, and mounts the file system immediately.
  • If the file system on the /dev/sdb device or the mount point directory do not exist, the playbook creates them.

Additional resources

  • The /usr/share/ansible/roles/rhel-system-roles.storage/README.md file.

21.5. Example Ansible playbook to manage logical volumes

The example Ansible playbook applies the storage role to create an LVM logical volume in a volume group.

Example 21.3. A playbook that creates a mylv logical volume in the myvg volume group

- hosts: all
  vars:
    storage_pools:
      - name: myvg
        disks:
          - sda
          - sdb
          - sdc
        volumes:
          - name: mylv
            size: 2G
            fs_type: ext4
            mount_point: /mnt/data
  roles:
    - rhel-system-roles.storage
  • The myvg volume group consists of the following disks:

    • /dev/sda
    • /dev/sdb
    • /dev/sdc
  • If the myvg volume group already exists, the playbook adds the logical volume to the volume group.
  • If the myvg volume group does not exist, the playbook creates it.
  • The playbook creates an Ext4 file system on the mylv logical volume, and persistently mounts the file system at /mnt.

Additional resources

  • The /usr/share/ansible/roles/rhel-system-roles.storage/README.md file.

21.6. Example Ansible playbook to enable online block discard

The example Ansible playbook applies the storage role to mount an XFS file system with online block discard enabled.

Example 21.4. A playbook that enables online block discard on /mnt/data/

---
- hosts: all
  vars:
    storage_volumes:
      - name: barefs
        type: disk
        disks:
          - sdb
        fs_type: xfs
        mount_point: /mnt/data
        mount_options: discard
  roles:
    - rhel-system-roles.storage

Additional resources

21.7. Example Ansible playbook to create and mount an Ext4 file system

The example Ansible playbook applies the storage role to create and mount an Ext4 file system.

Example 21.5. A playbook that creates Ext4 on /dev/sdb and mounts it at /mnt/data

---
- hosts: all
  vars:
    storage_volumes:
      - name: barefs
        type: disk
        disks:
          - sdb
        fs_type: ext4
        fs_label: label-name
        mount_point: /mnt/data
  roles:
    - rhel-system-roles.storage
  • The playbook creates the file system on the /dev/sdb disk.
  • The playbook persistently mounts the file system at the /mnt/data directory.
  • The label of the file system is label-name.

Additional resources

  • The /usr/share/ansible/roles/rhel-system-roles.storage/README.md file.

21.8. Example Ansible playbook to create and mount an ext3 file system

The example Ansible playbook applies the storage role to create and mount an Ext3 file system.

Example 21.6. A playbook that creates Ext3 on /dev/sdb and mounts it at /mnt/data

---
- hosts: all
  vars:
    storage_volumes:
      - name: barefs
        type: disk
        disks:
          - sdb
        fs_type: ext3
        fs_label: label-name
        mount_point: /mnt/data
  roles:
    - rhel-system-roles.storage
  • The playbook creates the file system on the /dev/sdb disk.
  • The playbook persistently mounts the file system at the /mnt/data directory.
  • The label of the file system is label-name.

Additional resources

  • The /usr/share/ansible/roles/rhel-system-roles.storage/README.md file.

21.9. Example Ansible playbook to resize an existing file system on LVM using the storage RHEL System Role

The example Ansible playbook applies the storage RHEL System Role to resize an LVM logical volume with a file system.

Warning

Using the Resizing action in other file systems can destroy the data on the device you are working on.

Example 21.7. A playbook that resizes existing mylv1 and myvl2 logical volumes in the myvg volume group

---

- hosts: all
   vars:
    storage_pools:
      - name: myvg
        disks:
          - /dev/sda
          - /dev/sdb
          - /dev/sdc
        volumes:
            - name: mylv1
              size: 10 GiB
              fs_type: ext4
              mount_point: /opt/mount1
            - name: mylv2
              size: 50 GiB
              fs_type: ext4
              mount_point: /opt/mount2

- name: Create LVM pool over three disks
  include_role:
    name: rhel-system-roles.storage
  • This playbook resizes the following existing file systems:

    • The Ext4 file system on the mylv1 volume, which is mounted at /opt/mount1, resizes to 10 GiB.
    • The Ext4 file system on the mylv2 volume, which is mounted at /opt/mount2, resizes to 50 GiB.

Additional resources

  • The /usr/share/ansible/roles/rhel-system-roles.storage/README.md file.

21.10. Example Ansible playbook to create a swap volume using the storage RHEL System Role

This section provides an example Ansible playbook. This playbook applies the storage role to create a swap volume, if it does not exist, or to modify the swap volume, if it already exist, on a block device using the default parameters.

Example 21.8. A playbook that creates or modify an existing XFS on /dev/sdb

---
- name: Create a disk device with swap
- hosts: all
  vars:
    storage_volumes:
      - name: swap_fs
        type: disk
        disks:
          - /dev/sdb
	size: 15 GiB
        fs_type: swap
  roles:
    - rhel-system-roles.storage
  • The volume name (swap_fs in the example) is currently arbitrary. The storage role identifies the volume by the disk device listed under the disks: attribute.

Additional resources

  • The /usr/share/ansible/roles/rhel-system-roles.storage/README.md file.

21.11. Configuring a RAID volume using the storage System Role

With the storage System Role, you can configure a RAID volume on RHEL using Red Hat Ansible Automation Platform and Ansible-Core. Create an Ansible playbook with the parameters to configure a RAID volume to suit your requirements.

Prerequisites

  • The Ansible Core package is installed on the control machine.
  • You have the rhel-system-roles package installed on the system from which you want to run the playbook.
  • You have an inventory file detailing the systems on which you want to deploy a RAID volume using the storage System Role.

Procedure

  1. Create a new playbook.yml file with the following content:

    ---
    - name: Configure the storage
      hosts: managed-node-01.example.com
      tasks:
      - name: Create a RAID on sdd, sde, sdf, and sdg
        include_role:
          name: rhel-system-roles.storage
        vars:
        storage_safe_mode: false
        storage_volumes:
          - name: data
            type: raid
            disks: [sdd, sde, sdf, sdg]
            raid_level: raid0
            raid_chunk_size: 32 KiB
            mount_point: /mnt/data
            state: present
    Warning

    Device names might change in certain circumstances, for example, when you add a new disk to a system. Therefore, to prevent data loss, do not use specific disk names in the playbook.

  2. Optional: Verify the playbook syntax:

    # ansible-playbook --syntax-check playbook.yml
  3. Run the playbook:

    # ansible-playbook -i inventory.file /path/to/file/playbook.yml

Additional resources

21.12. Configuring an LVM pool with RAID using the storage RHEL System Role

With the storage System Role, you can configure an LVM pool with RAID on RHEL using Red Hat Ansible Automation Platform. You can set up an Ansible playbook with the available parameters to configure an LVM pool with RAID.

Prerequisites

  • The Ansible Core package is installed on the control machine.
  • You have the rhel-system-roles package installed on the system from which you want to run the playbook.
  • You have an inventory file detailing the systems on which you want to configure an LVM pool with RAID using the storage System Role.

Procedure

  1. Create a new playbook.yml file with the following content:

    - hosts: all
      vars:
        storage_safe_mode: false
        storage_pools:
          - name: my_pool
            type: lvm
            disks: [sdh, sdi]
            raid_level: raid1
            volumes:
              - name: my_pool
                size: "1 GiB"
                mount_point: "/mnt/app/shared"
                fs_type: xfs
                state: present
      roles:
        - name: rhel-system-roles.storage
    Note

    To create an LVM pool with RAID, you must specify the RAID type using the raid_level parameter.

  2. Optional. Verify playbook syntax.

    # ansible-playbook --syntax-check playbook.yml
  3. Run the playbook on your inventory file:

    # ansible-playbook -i inventory.file /path/to/file/playbook.yml

Additional resources

  • Managing RAID.
  • The /usr/share/ansible/roles/rhel-system-roles.storage/README.md file.

21.13. Example Ansible playbook to compress and deduplicate a VDO volume on LVM using the storage RHEL System Role

The example Ansible playbook applies the storage RHEL System Role to enable compression and deduplication of Logical Volumes (LVM) using Virtual Data Optimizer (VDO).

Example 21.9. A playbook that creates a mylv1 LVM VDO volume in the myvg volume group

---
- name: Create LVM VDO volume under volume group 'myvg'
  hosts: all
  roles:
    -rhel-system-roles.storage
  vars:
    storage_pools:
     - name: myvg
       disks:
         - /dev/sdb
       volumes:
         - name: mylv1
           compression: true
           deduplication: true
           vdo_pool_size: 10 GiB
           size: 30 GiB
           mount_point: /mnt/app/shared

In this example, the compression and deduplication pools are set to true, which specifies that the VDO is used. The following describes the usage of these parameters:

  • The deduplication is used to deduplicate the duplicated data stored on the storage volume.
  • The compression is used to compress the data stored on the storage volume, which results in more storage capacity.
  • The vdo_pool_size specifies the actual size the volume takes on the device. The virtual size of VDO volume is set by the size parameter. NOTE: Because of the Storage role use of LVM VDO, only one volume per pool can use the compression and deduplication.

21.14. Creating a LUKS2 encrypted volume using the storage RHEL System Role

You can use the storage role to create and configure a volume encrypted with LUKS by running an Ansible playbook.

Prerequisites

  • Access and permissions to one or more managed nodes, which are systems you want to configure with the crypto_policies System Role.
  • An inventory file, which lists the managed nodes.
  • Access and permissions to a control node, which is a system from which Red Hat Ansible Core configures other systems. On the control node, the ansible-core and rhel-system-roles packages are installed.
Important

RHEL 8.0-8.5 provided access to a separate Ansible repository that contains Ansible Engine 2.9 for automation based on Ansible. Ansible Engine contains command-line utilities such as ansible, ansible-playbook, connectors such as docker and podman, and many plugins and modules. For information about how to obtain and install Ansible Engine, see the How to download and install Red Hat Ansible Engine Knowledgebase article.

RHEL 8.6 and 9.0 have introduced Ansible Core (provided as the ansible-core package), which contains the Ansible command-line utilities, commands, and a small set of built-in Ansible plugins. RHEL provides this package through the AppStream repository, and it has a limited scope of support. For more information, see the Scope of support for the Ansible Core package included in the RHEL 9 and RHEL 8.6 and later AppStream repositories Knowledgebase article.

Procedure

  1. Create a new playbook.yml file with the following content:

    - hosts: all
      vars:
        storage_volumes:
          - name: barefs
            type: disk
            disks:
             - sdb
            fs_type: xfs
            fs_label: label-name
            mount_point: /mnt/data
            encryption: true
            encryption_password: your-password
      roles:
       - rhel-system-roles.storage

    You can also add the other encryption parameters such as encryption_key, encryption_cipher, encryption_key_size, and encryption_luks version in the playbook.yml file.

  2. Optional: Verify playbook syntax:

    # ansible-playbook --syntax-check playbook.yml
  3. Run the playbook on your inventory file:

    # ansible-playbook -i inventory.file /path/to/file/playbook.yml

Verification

  1. View the encryption status:

    # cryptsetup status sdb
    
    /dev/mapper/sdb is active and is in use.
    type: LUKS2
    cipher: aes-xts-plain64
    keysize: 512 bits
    key location: keyring
    device: /dev/sdb
    [...]
  2. Verify the created LUKS encrypted volume:

    # cryptsetup luksDump /dev/sdb
    
    Version:       	2
    Epoch:         	6
    Metadata area: 	16384 [bytes]
    Keyslots area: 	33521664 [bytes]
    UUID:          	a4c6be82-7347-4a91-a8ad-9479b72c9426
    Label:         	(no label)
    Subsystem:     	(no subsystem)
    Flags:       	allow-discards
    
    Data segments:
      0: crypt
    	offset: 33554432 [bytes]
    	length: (whole device)
    	cipher: aes-xts-plain64
    	sector: 4096 [bytes]
    [...]
  3. View the cryptsetup parameters in the playbook.yml file, which the storage role supports:

    # cat ~/playbook.yml
    
        - hosts: all
          vars:
            storage_volumes:
              - name: foo
                type: disk
                disks:
                 - nvme0n1
                fs_type: xfs
                fs_label: label-name
                mount_point: /mnt/data
                encryption: true
                #encryption_password: passwdpasswd
                encryption_key: /home/passwd_key
                encryption_cipher: aes-xts-plain64
                encryption_key_size: 512
                encryption_luks_version: luks2
    
          roles:
           - rhel-system-roles.storage

Additional resources

21.15. Example Ansible playbook to express pool volume sizes as percentage using the storage RHEL System Role

The example Ansible playbook applies the storage System Role to enable you to express Logical Manager Volumes (LVM) volume sizes as a percentage of the pool’s total size.

Example 21.10. A playbook that express volume sizes as a percentage of the pool’s total size

---
- name: Express volume sizes as a percentage of the pool's total size
  hosts: all
  roles
    - rhel-system-roles.storage
  vars:
    storage_pools:
    - name: myvg
      disks:
        - /dev/sdb
      volumes:
        - name: data
          size: 60%
          mount_point: /opt/mount/data
        - name: web
          size: 30%
          mount_point: /opt/mount/web
        - name: cache
          size: 10%
          mount_point: /opt/cache/mount

This example specifies the size of LVM volumes as a percentage of the pool size, for example: "60%". Additionally, you can also specify the size of LVM volumes as a percentage of the pool size in a human-readable size of the file system, for example, "10g" or "50 GiB".

21.16. Additional resources

  • /usr/share/doc/rhel-system-roles/storage/
  • /usr/share/ansible/roles/rhel-system-roles.storage/

Chapter 22. Configuring time synchronization by using the timesync RHEL System Role

With the timesync RHEL System Role, you can manage time synchronization on multiple target machines on RHEL using Red Hat Ansible Automation Platform.

22.1. The timesync RHEL System Role

You can manage time synchronization on multiple target machines using the timesync RHEL System Role.

The timesync role installs and configures an NTP or PTP implementation to operate as an NTP client or PTP replica in order to synchronize the system clock with NTP servers or grandmasters in PTP domains.

Note that using the timesync role also facilitates the Migrating to chrony, because you can use the same playbook on all versions of Red Hat Enterprise Linux starting with RHEL 6 regardless of whether the system uses ntp or chrony to implement the NTP protocol.

22.2. Applying the timesync System Role for a single pool of servers

The following example shows how to apply the timesync role in a situation with just one pool of servers.

Warning

The timesync role replaces the configuration of the given or detected provider service on the managed host. Previous settings are lost, even if they are not specified in the role variables. The only preserved setting is the choice of provider if the timesync_ntp_provider variable is not defined.

Prerequisites

  • The Ansible Core package is installed on the control machine.
  • You have the rhel-system-roles package installed on the system from which you want to run the playbook.
  • You have an inventory file which lists the systems on which you want to deploy timesync System Role.

Procedure

  1. Create a new playbook.yml file with the following content:

    ---
    - hosts: timesync-test
      vars:
        timesync_ntp_servers:
          - hostname: 2.rhel.pool.ntp.org
            pool: yes
            iburst: yes
      roles:
        - rhel-system-roles.timesync
  2. Optional: Verify playbook syntax.

    # ansible-playbook --syntax-check playbook.yml
  3. Run the playbook on your inventory file:

    # ansible-playbook -i inventory_file /path/to/file/playbook.yml

22.3. Applying the timesync System Role on client servers

You can use the timesync role to enable Network Time Security (NTS) on NTP clients. Network Time Security (NTS) is an authentication mechanism specified for Network Time Protocol (NTP). It verifies that NTP packets exchanged between the server and client are not altered.

Warning

The timesync role replaces the configuration of the given or detected provider service on the managed host. Previous settings are lost even if they are not specified in the role variables. The only preserved setting is the choice of provider if the timesync_ntp_provider variable is not defined.

Prerequisites

  • You do not have to have Red Hat Ansible Automation Platform installed on the systems on which you want to deploy the timesync solution.
  • You have the rhel-system-roles package installed on the system from which you want to run the playbook.
  • You have an inventory file which lists the systems on which you want to deploy the timesync System Role.
  • The chrony NTP provider version is 4.0 or later.

Procedure

  1. Create a playbook.yml file with the following content:

    ---
    - hosts: timesync-test
      vars:
        timesync_ntp_servers:
          - hostname: ptbtime1.ptb.de
            iburst: yes
            nts: yes
      roles:
        - rhel-system-roles.timesync

    ptbtime1.ptb.de is an example of public server. You may want to use a different public server or your own server.

  2. Optional: Verify playbook syntax.

    # ansible-playbook --syntax-check playbook.yml
  3. Run the playbook on your inventory file:

    # ansible-playbook -i inventory_file /path/to/file/playbook.yml

Verification

  1. Perform a test on the client machine:

    # chronyc -N authdata
    
    Name/IP address         Mode KeyID Type KLen Last Atmp  NAK Cook CLen
    =====================================================================
    ptbtime1.ptb.de         NTS     1   15  256  157    0    0    8  100
  2. Check that the number of reported cookies is larger than zero.

Additional resources

  • chrony.conf(5) man page

22.4. timesync System Roles variables

You can pass the following variable to the timesync role:

  • timesync_ntp_servers:
Role variable settingsDescription

hostname: host.example.com

Hostname or address of the server

minpoll: number

Minimum polling interval. Default: 6

maxpoll: number

Maximum polling interval. Default: 10

iburst: yes

Flag enabling fast initial synchronization. Default: no

pool: yes

Flag indicating that each resolved address of the hostname is a separate NTP server. Default: no

nts: yes

Flag to enable Network Time Security (NTS). Default: no. Supported only with chrony >= 4.0.

Additional resources

  • For a detailed reference on timesync role variables, install the rhel-system-roles package, and see the README.md or README.html files in the /usr/share/doc/rhel-system-roles/timesync directory.

Chapter 23. Monitoring performance by using the metrics RHEL System Role

As a system administrator, you can use the metrics RHEL System Role with any Ansible Automation Platform control node to monitor the performance of a system.

23.1. Introduction to the metrics System Role

RHEL System Roles is a collection of Ansible roles and modules that provide a consistent configuration interface to remotely manage multiple RHEL systems. The metrics System Role configures performance analysis services for the local system and, optionally, includes a list of remote systems to be monitored by the local system. The metrics System Role enables you to use pcp to monitor your systems performance without having to configure pcp separately, as the set-up and deployment of pcp is handled by the playbook.

Table 23.1. metrics system role variables

Role variableDescriptionExample usage

metrics_monitored_hosts

List of remote hosts to be analyzed by the target host. These hosts will have metrics recorded on the target host, so ensure enough disk space exists below /var/log for each host.

metrics_monitored_hosts: ["webserver.example.com", "database.example.com"]

metrics_retention_days

Configures the number of days for performance data retention before deletion.

metrics_retention_days: 14

metrics_graph_service

A boolean flag that enables the host to be set up with services for performance data visualization via pcp and grafana. Set to false by default.

metrics_graph_service: no

metrics_query_service

A boolean flag that enables the host to be set up with time series query services for querying recorded pcp metrics via redis. Set to false by default.

metrics_query_service: no

metrics_provider

Specifies which metrics collector to use to provide metrics. Currently, pcp is the only supported metrics provider.

metrics_provider: "pcp"

metrics_manage_firewall

Uses the firewall role to manage port access directly from the metrics role. Set to false by default.

metrics_manage_firewall: true

metrics_manage_selinux

Uses the selinux role to manage port access directly from the metrics role. Set to false by default.

metrics_manage_selinux: true

Note

For details about the parameters used in metrics_connections and additional information about the metrics System Role, see the /usr/share/ansible/roles/rhel-system-roles.metrics/README.md file.

23.2. Using the metrics System Role to monitor your local system with visualization

This procedure describes how to use the metrics RHEL System Role to monitor your local system while simultaneously provisioning data visualization via Grafana.

Prerequisites

  • The Ansible Core package is installed on the control machine.
  • You have the rhel-system-roles package installed on the machine you want to monitor.

Procedure

  1. Configure localhost in the /etc/ansible/hosts Ansible inventory by adding the following content to the inventory:

    localhost ansible_connection=local
  2. Create an Ansible playbook with the following content:

    ---
    - name: Manage metrics
      hosts: localhost
      vars:
        metrics_graph_service: yes
        metrics_manage_firewall: true
        metrics_manage_selinux: true
      roles:
        - rhel-system-roles.metrics
  3. Run the Ansible playbook:

    # ansible-playbook name_of_your_playbook.yml
    Note

    Because the metrics_graph_service boolean is set to value="yes", Grafana is automatically installed and provisioned with pcp added as a data source. Because metrics_manage_firewall and metrics_manage_selinux are both set to true, the metrics role uses the firewall and selinux system roles to manage the ports used by the metrics role.

  4. To view visualization of the metrics being collected on your machine, access the grafana web interface as described in Accessing the Grafana web UI.

23.3. Using the metrics System Role to set up a fleet of individual systems to monitor themselves

This procedure describes how to use the metrics System Role to set up a fleet of machines to monitor themselves.

Prerequisites

  • The Ansible Core package is installed on the control machine.
  • You have the rhel-system-roles package installed on the machine you want to use to run the playbook.
  • You have the SSH connection established.

Procedure

  1. Add the name or IP address of the machines you want to monitor via the playbook to the /etc/ansible/hosts Ansible inventory file under an identifying group name enclosed in brackets:

    [remotes]
    webserver.example.com
    database.example.com
  2. Create an Ansible playbook with the following content:

    ---
    - hosts: remotes
      vars:
        metrics_retention_days: 0
        metrics_manage_firewall: true
        metrics_manage_selinux: true
      roles:
        - rhel-system-roles.metrics
    Note

    Because metrics_manage_firewall and metrics_manage_selinux are both set to true, the metrics role uses the firewall and selinux roles to manage the ports used by the metrics role.

  3. Run the Ansible playbook:

    # ansible-playbook name_of_your_playbook.yml -k

    Where the -k prompt for password to connect to remote system.

23.4. Using the metrics System Role to monitor a fleet of machines centrally via your local machine

This procedure describes how to use the metrics System Role to set up your local machine to centrally monitor a fleet of machines while also provisioning visualization of the data via grafana and querying of the data via redis.

Prerequisites

  • The Ansible Core package is installed on the control machine.
  • You have the rhel-system-roles package installed on the machine you want to use to run the playbook.

Procedure

  1. Create an Ansible playbook with the following content:

    ---
    - hosts: localhost
      vars:
        metrics_graph_service: yes
        metrics_query_service: yes
        metrics_retention_days: 10
        metrics_monitored_hosts: ["database.example.com", "webserver.example.com"]
        metrics_manage_firewall: yes
        metrics_manage_selinux: yes
      roles:
        - rhel-system-roles.metrics
  2. Run the Ansible playbook:

    # ansible-playbook name_of_your_playbook.yml
    Note

    Because the metrics_graph_service and metrics_query_service booleans are set to value="yes", grafana is automatically installed and provisioned with pcp added as a data source with the pcp data recording indexed into redis, allowing the pcp querying language to be used for complex querying of the data. Because metrics_manage_firewall and metrics_manage_selinux are both set to true, the metrics role uses the firewall and selinux roles to manage the ports used by the metrics role.

  3. To view a graphical representation of the metrics being collected centrally by your machine and to query the data, access the grafana web interface as described in Accessing the Grafana web UI.

23.5. Setting up authentication while monitoring a system using the metrics System Role

PCP supports the scram-sha-256 authentication mechanism through the Simple Authentication Security Layer (SASL) framework. The metrics RHEL System Role automates the steps to setup authentication using the scram-sha-256 authentication mechanism. This procedure describes how to setup authentication using the metrics RHEL System Role.

Prerequisites

  • The Ansible Core package is installed on the control machine.
  • You have the rhel-system-roles package installed on the machine you want to use to run the playbook.

Procedure

  1. Include the following variables in the Ansible playbook you want to setup authentication for:

    ---
      vars:
        metrics_username: your_username
        metrics_password: your_password
        metrics_manage_firewall: true
        metrics_manage_selinux: true
    Note

    Because metrics_manage_firewall and metrics_manage_selinux are both set to true, the metrics role uses the firewall and selinux roles to manage the ports used by the metrics role.

  2. Run the Ansible playbook:

    # ansible-playbook name_of_your_playbook.yml

Verification steps

  • Verify the sasl configuration:

    # pminfo -f -h "pcp://ip_adress?username=your_username" disk.dev.read
    Password:
    disk.dev.read
    inst [0 or "sda"] value 19540

    ip_adress should be replaced by the IP address of the host.

23.6. Using the metrics System Role to configure and enable metrics collection for SQL Server

This procedure describes how to use the metrics RHEL System Role to automate the configuration and enabling of metrics collection for Microsoft SQL Server via pcp on your local system.

Prerequisites

  • The Ansible Core package is installed on the control machine.
  • You have the rhel-system-roles package installed on the machine you want to monitor.
  • You have installed Microsoft SQL Server for Red Hat Enterprise Linux and established a 'trusted' connection to an SQL server. See Install SQL Server and create a database on Red Hat.
  • You have installed the Microsoft ODBC driver for SQL Server for Red Hat Enterprise Linux. See Red Hat Enterprise Server and Oracle Linux.

Procedure

  1. Configure localhost in the /etc/ansible/hosts Ansible inventory by adding the following content to the inventory:

    localhost ansible_connection=local
  2. Create an Ansible playbook that contains the following content:

    ---
    - hosts: localhost
      vars:
       metrics_from_mssql: true
       metrics_manage_firewall: true
       metrics_manage_selinux: true
      roles:
       - role: rhel-system-roles.metrics
    Note

    Because metrics_manage_firewall and metrics_manage_selinux are both set to true, the metrics role uses the firewall and selinux roles to manage the ports used by the metrics role.

  3. Run the Ansible playbook:

    # ansible-playbook name_of_your_playbook.yml

Verification steps

  • Use the pcp command to verify that SQL Server PMDA agent (mssql) is loaded and running:

    # pcp
    platform: Linux rhel82-2.local 4.18.0-167.el8.x86_64 #1 SMP Sun Dec 15 01:24:23 UTC 2019 x86_64
     hardware: 2 cpus, 1 disk, 1 node, 2770MB RAM
     timezone: PDT+7
     services: pmcd pmproxy
         pmcd: Version 5.0.2-1, 12 agents, 4 clients
         pmda: root pmcd proc pmproxy xfs linux nfsclient mmv kvm mssql
               jbd2 dm
     pmlogger: primary logger: /var/log/pcp/pmlogger/rhel82-2.local/20200326.16.31
         pmie: primary engine: /var/log/pcp/pmie/rhel82-2.local/pmie.log

Chapter 24. Configuring Microsoft SQL Server using the microsoft.sql.server Ansible role

As an administrator, you can use the microsoft.sql.server Ansible role to install, configure, and start Microsoft SQL Server (SQL Server). The microsoft.sql.server Ansible role optimizes your operating system to improve performance and throughput for the SQL Server. The role simplifies and automates the configuration of your RHEL host with recommended settings to run the SQL Server workloads.

24.1. Prerequisites

  • 2 GB of RAM
  • root access to the managed node where you want to configure SQL Server
  • Pre-configured firewall

    You can set the mssql_manage_firewall variable to true so that the role can manage firewall automatically.

    Alternatively, enable the connection on the SQL Server TCP port set with the mssql_tcp_port variable. If you do not define this variable, the role defaults to the TCP port number 1433.

    To add a new port, use:

    # firewall-cmd --add-port=xxxx/tcp --permanent
    # firewall-cmd --reload

    Replace xxxx with the TCP port number then reload the firewall rules.

  • Optional: Create a file with the .sql extension containing the SQL statements and procedures to input them to SQL Server.

24.2. Installing the microsoft.sql.server Ansible role

The microsoft.sql.server Ansible role is part of the ansible-collection-microsoft-sql package.

Prerequisites

  • root access

Procedure

  1. Install Ansible Core which is available in the RHEL 8 AppStream repository:

    # yum install ansible-core
  2. Install the microsoft.sql.server Ansible role:

    # yum install ansible-collection-microsoft-sql

24.3. Installing and configuring SQL server using the microsoft.sql.server Ansible role with existing certificate files

You can use the microsoft.sql.server Ansible role to install and configure SQL Server version 2019. The playbook in this example also configures the server to use an existing sql_cert certificate and private key files for TLS encryption.

Prerequisites

  • An inventory file exists on the control node.

Procedure

  1. Create a new playbook.yml file with the following content:

    ---
    - name: Install and configure SQL Server
      hosts: all
      roles:
        - microsoft.sql.server
      vars:
        mssql_accept_microsoft_odbc_driver_17_for_sql_server_eula: true
        mssql_accept_microsoft_cli_utilities_for_sql_server_eula: true
        mssql_accept_microsoft_sql_server_standard_eula: true
        mssql_version: 2019
        mssql_manage_firewall: true
        mssql_tls_enable: true
        mssql_tls_cert: sql_crt.pem
        mssql_tls_private_key: sql_cert.key
        mssql_tls_version: 1.2
        mssql_tls_force: false
        mssql_password: <password>
        mssql_edition: Developer
        mssql_tcp_port: 1433

    Replace <password> with your SQL Server password.

  2. Run the playbook on your inventory:

    # ansible-playbook -i inventory_file /path/to/file/playbook.yml

24.4. Installing and configuring SQL server using the microsoft.sql.server Ansible role with the certificate role

You can use the microsoft.sql.server Ansible role to install and configure SQL Server version 2019. The playbook in this example also configures the server to use TLS encryption and creates a self-signed sql_cert certificate file and private key using the certificate System Role.

Note

You do not have to call the certificate System Role in the playbook to create the certificate. The microsoft.sql.server Ansible role calls it automatically.

In order for the CA to be able to sign the created certificate, the managed nodes must be enrolled in an IdM domain.

Prerequisites

  • An inventory file exists on the control node.

Procedure

  1. Create a new playbook.yml file with the following content:

    ---
    - name: Install and configure SQL Server
      hosts: all
      roles:
        - microsoft.sql.server
      vars:
        mssql_accept_microsoft_odbc_driver_17_for_sql_server_eula: true
        mssql_accept_microsoft_cli_utilities_for_sql_server_eula: true
        mssql_accept_microsoft_sql_server_standard_eula: true
        mssql_version: 2019
        mssql_manage_firewall: true
        mssql_tls_enable: true
        mssql_tls_certificates:
          - name: sql_cert
            dns: *.example.com
            ca: self-sign
        mssql_password: <password>
        mssql_edition: Developer
        mssql_tcp_port: 1433

    Replace <password> with your SQL Server password.

  2. Run the playbook on your inventory:

    # ansible-playbook -i inventory_file /path/to/file/playbook.yml

24.5. TLS variables

You can use the following variables to configure the Transport Level Security (TLS) protocol.

Table 24.1. TLS role variables

Role variableDescription

mssql_version

Defines which version of SQL server to install. Possible values are 2017, 2019 and 2022.

mssql_tls_enable

This variable enables or disables TLS encryption.

The microsoft.sql.server Ansible role performs following tasks when the variable is set to true:

  • Copies or generates a TLS certificate in /etc/pki/tls/certs/ on the SQL Server
  • Copies or generates a private key in /etc/pki/tls/private/ on the SQL Server
  • Configures the SQL Server to use TLS certificate and private key to encrypt connections

When set to false, the TLS encryption is disabled. The role does not remove the existing certificate and private key files.

mssql_tls_certificates

Generates a certificate and a private key for TLS encryption using the certificate role.

Important

When you set this variable, you must not set mssql_tls_cert and mssql_tls_private_key variables.

mssql_tls_cert

Copies a certificate file from the specified path to SQL Server and uses it for TLS encryption.

mssql_tls_private_key

Copies a private key file from the specified path to SQL Server and uses it for TLS encryption.

mssql_tls_remote_src

Defines if the role searches for mssql_tls_cert and mssql_tls_private_key files remotely or on the control node.

When set to the default false, the role searches for mssql_tls_cert or mssql_tls_private_key files on the Ansible control node.

When set to true, the role searches for mssql_tls_cert or mssql_tls_private_key files on the Ansible managed node.

mssql_tls_version

Defines which TLS version to use.

The default is 1.2.

mssql_tls_force

If set to true, replaces the certificate and private key files on the host. The files must exist under /etc/pki/tls/certs/ and /etc/pki/tls/private/ directories.

The default is false.

24.6. Preparing and running a playbook to enable SQL Server authentication with Active Directory

To be able to automatically authenticate your Microsoft SQL server with Active Directory, you need to set up an microsoft.sql.server Ansible playbook with variables according to your use case. .Prerequisites

  • The Ansible inventory is prepared.

Procedure

  1. Create a new playbook.yml with the following content:

    ---
    - name: Configure with AD server authentication
      hosts: all
      vars:
        # General variables
        mssql_accept_microsoft_odbc_driver_17_for_sql_server_eula: true
        mssql_accept_microsoft_cli_utilities_for_sql_server_eula: true
        mssql_accept_microsoft_sql_server_standard_eula: true
        mssql_version: 2022
        mssql_password: "p@55w0rD"
        mssql_edition: Evaluation
        mssql_manage_firewall: true
        # AD Integration required variables
        mssql_ad_configure: true
        mssql_ad_sql_user_name: sqluser
        mssql_ad_sql_password: "p@55w0rD1"
        ad_integration_realm: domain.com
        ad_integration_user: Administrator
        ad_integration_password: Secret123
      roles:
        - microsoft.sql.server
  2. Optional: Verify the playbook syntax.

    # ansible-playbook --syntax-check playbook.yml
  3. Run the playbook on yout inventory file.

    # ansible-playbook -i inventory_file /path/to/file/playbook.yml

Next steps

  • Finish the configuration. For more information, see Configuring SQL Server to authenticate with Active Directory (AD) Server.

24.7. Configuring SQL Server to authenticate with Active Directory (AD) Server

The following procedure shows how to configure SQL Server to authenticate with Active Directory (AD) Server.

Prerequisites

  • An Active Directory domain controller is configured on your network.
  • An applicable RDNS (Reverse DNS) zone exists for both the domain controller and the IP address of the Linux machine that will be running SQL Server.
  • A PTR record that points to your domain controllers exists.
  • The SQL Server host resolves relative domain name, fully qualified domain name, and the IP of the domain controller to the fully qualified domain name of the domain controller.

Procedure

  1. Log in to your AD server via the web UI.
  2. Navigate to Tools > Active Directory Users and Computers > domain.com > Users > sqluser > Account.
  3. In the Account options list, select This account supports Kerberos AES 128 bit encryption and This account supports Kerberos AES 256 bit encryption.
  4. Click Apply

Verification

  1. Use ssh to log in to the client.domain.com machine:

    # ssh -l <sqluser>@<domain.com> <client.domain.com>
  2. Obtain Kerberos ticket for the Administrator user:

    # kinit Administrator@<DOMAIN.COM>
  3. Use sqlcmd to log in to SQL Server and, for example, run the query to get current user:

    # /opt/mssql-tools/bin/sqlcmd -S. -Q 'SELECT SYSTEM_USER'

24.8. Variables for SQL Server integration with Active Directory Server

You can use the following variables to configure the SQL Server to authenticate with Active Directory (AD) Server.

Table 24.2. Active Directory variables

Role variableDescription

mssql_ad_configure

This variable enables or disables configuration for AD Server authentication. The default value is false When set to true, the configure for AD Server authentication is enabled. The role does not remove configuration for AD Server authentication.

mssql_ad_sql_user_name

You can define a username that is going to be created in SQL server and then used for authentication.

mssql_ad_sql_password

You can define a password for a user defined in mssql_ad_sql_user_name that is going to be created in SQL server and then used for authentication.

mssql_ad_sql_user_dn

You have to set ssql_ad_sql_user_dn variable when your AD server stores user account in a custom Organization Unit rather than in the Users Organization Unit.

mssql_ad_netbios_name

You have to set mssql_ad_netbios_name variable when your NetBIOS domain name of your AD server does not equal to the first subdomain of the domain name that you provide with the ad_integration_realm variable.

24.9. Accepting EULA for MLServices

You must accept all the EULA for the open-source distributions of Python and R packages to install the required SQL Server Machine Learning Services (MLServices).

See /usr/share/doc/mssql-server for the license terms.

Table 24.3. SQL Server Machine Learning Services EULA variables

Role variableDescription

mssql_accept_microsoft_sql_server_standard_eula

This variable determines whether to accept the terms and conditions for installing the mssql-conf package.

To accept the terms and conditions set this variable to true.

The default is false.

24.10. Accepting EULAs for Microsoft ODBC 17

You must accept all the EULAs to install the Microsoft Open Database Connectivity (ODBC) driver.

See /usr/share/doc/msodbcsql17/LICENSE.txt and /usr/share/doc/mssql-tools/LICENSE.txt for the license terms.

Table 24.4. Microsoft ODBC 17 EULA variables

Role variableDescription

mssql_accept_microsoft_odbc_driver_17_for_sql_server_eula

This variable determines whether to accept the terms and conditions for installing the msodbcsql17 package.

To accept the terms and conditions set this variable to true.

The default is false.

mssql_accept_microsoft_cli_utilities_for_sql_server_eula

This variable determines whether to accept the terms and conditions for installing the mssql-tools package.

To accept the terms and conditions set this variable to true.

The default is false.

24.11. High availability variables

You can configure high availability for Microsoft SQL Server with the variables from the table below.

Table 24.5. High availability configuration variables

VariableDescription

mssql_ha_configure

The default value is false.

When it is set to true, performs the following actions:

  • Configures firewall by opening a port from the mssql_ha_listener_port variable and enables the high-availability service in firewall.
  • Configures SQL Server for high availability.

    • Enables Always On Health events.
    • Creates certificate on the primary replica and distributes it to other replicas.
    • Configures endpoint and availability group.
    • Configures the user from the mssql_ha_login variable for Pacemaker.
  • Optional: Includes the System Roles ha_cluster role to configure Pacemaker. You must set mssql_ha_cluster_run_role to true and provide all variables that the ha_cluster role requires for a Pacemaker cluster configuration.

mssql_ha_replica_type

This variable specifies which type of replica you can configure on the host. You can set this variable to primary, synchronous, and witness. You must set it to primary only on one host.

mssql_ha_listener_port

The default port is 5022.

The role uses this TCP port to replicate data for an Always On availability group.

mssql_ha_cert_name

You must define the name of the certificate to secure transactions between members of an Always On availability group.

mssql_ha_master_key_password

You must set the password for the master key to use with the certificate.

mssql_ha_private_key_password

You must set the password for the private key to use with the certificate.

mssql_ha_reset_cert

The default value is false.

If it is set to true, resets the certificate which an Always On availability group uses.

mssql_ha_endpoint_name

You must define the name of the endpoint to configure.

mssql_ha_ag_name

You must define the name of the availability group to configure.

mssql_ha_db_names

You can define a list of the databases to replicate, otherwise the role creates a cluster without replicating databases.

mssql_ha_login

The SQL Server Pacemaker resource agent utilizes this user to perform database health checks and manage state transitions from replica to primary server.

mssql_ha_login_password

The password for the mssql_ha_login user in SQL Server.

mssql_ha_cluster_run_role

The default value is false.

This variable defines if this role runs the ha_cluster role.

Note that the ha_cluster role replaces the configuration of the HA cluster on specified nodes, any variables currently configured for the HA cluster are erased and overwritten.

To work around this limitation, the microsoft.sql.server role does not set any variables for the ha_cluster role to ensure that it does not overwrite any existing Pacemaker configuration.

If you want the microsoft.sql.server to run the ha_cluster role, set this variable to true and provide variables for the ha_cluster role with the microsoft.sql.server role call.

Note, this role backs up the database to the /var/opt/mssql/data/ directory.

For examples on how to use high availability variables for Microsoft SQL Server:

  • If you install the role from Automation Hub, see the ~/.ansible/collections/ansible_collections/microsoft/sql/roles/server/README.md file on your server.
  • If you install the role from a package, open the /usr/share/microsoft/sql-server/README.html file in your browser.

Chapter 25. Configuring a system for session recording using the tlog RHEL System Role

With the tlog RHEL System Role, you can configure a system for terminal session recording on RHEL using Red Hat Ansible Automation Platform.

25.1. The tlog System Role

You can configure a RHEL system for terminal session recording on RHEL using the tlog RHEL System Role.

You can configure the recording to take place per user or user group by means of the SSSD service.

Additional resources

25.2. Components and parameters of the tlog System Role

The Session Recording solution has the following components:

  • The tlog utility
  • System Security Services Daemon (SSSD)
  • Optional: The web console interface

The parameters used for the tlog RHEL System Role are:

Role VariableDescription

tlog_use_sssd (default: yes)

Configure session recording with SSSD, the preferred way of managing recorded users or groups

tlog_scope_sssd (default: none)

Configure SSSD recording scope - all / some / none

tlog_users_sssd (default: [])

YAML list of users to be recorded

tlog_groups_sssd (default: [])

YAML list of groups to be recorded

  • For details about the parameters used in tlog and additional information about the tlog System Role, see the /usr/share/ansible/roles/rhel-system-roles.tlog/README.md file.

25.3. Deploying the tlog RHEL System Role

Follow these steps to prepare and apply an Ansible playbook to configure a RHEL system to log session recording data to the systemd journal.

Prerequisites

  • You have set SSH keys for access from the control node to the target system where the tlog System Role will be configured.
  • You have at least one system that you want to configure the tlog System Role.
  • The Ansible Core package is installed on the control machine.
  • The rhel-system-roles package is installed on the control machine.

Procedure

  1. Create a new playbook.yml file with the following content:

    ---
    - name: Deploy session recording
      hosts: all
      vars:
        tlog_scope_sssd: some
        tlog_users_sssd:
          - recorded-user
    
      roles:
        - rhel-system-roles.tlog

    Where,

    • tlog_scope_sssd:

      • some specifies you want to record only certain users and groups, not all or none.
    • tlog_users_sssd:

      • recorded-user specifies the user you want to record a session from. Note that this does not add the user for you. You must set the user by yourself.
  2. Optionally, verify the playbook syntax.

    # ansible-playbook --syntax-check playbook.yml
  3. Run the playbook on your inventory file:

    # ansible-playbook -i IP_Address /path/to/file/playbook.yml -v

As a result, the playbook installs the tlog RHEL System Role on the system you specified. The role includes tlog-rec-session, a terminal session I/O logging program, that acts as the login shell for a user. It also creates an SSSD configuration drop file that can be used by the users and groups that you define. SSSD parses and reads these users and groups, and replaces their user shell with tlog-rec-session. Additionally, if the cockpit package is installed on the system, the playbook also installs the cockpit-session-recording package, which is a Cockpit module that allows you to view and play recordings in the web console interface.

Verification steps

To verify that the SSSD configuration drop file is created in the system, perform the following steps:

  1. Navigate to the folder where the SSSD configuration drop file is created:

    # cd /etc/sssd/conf.d
  2. Check the file content:

    # cat /etc/sssd/conf.d/sssd-session-recording.conf

You can see that the file contains the parameters you set in the playbook.

25.4. Deploying the tlog RHEL System Role for excluding lists of groups or users

You can use the tlog System Role to support the SSSD session recording configuration options exclude_users and exclude_groups. Follow these steps to prepare and apply an Ansible playbook to configure a RHEL system to exclude users or groups from having their sessions recorded and logged in the systemd journal.

Prerequisites

  • You have set SSH keys for access from the control node to the target system on which you want to configure the tlog System Role.
  • You have at least one system on which you want to configure the tlog System Role.
  • The Ansible Core package is installed on the control machine.
  • The rhel-system-roles package is installed on the control machine.

Procedure

  1. Create a new playbook.yml file with the following content:

    ---
    - name: Deploy session recording excluding users and groups
      hosts: all
      vars:
        tlog_scope_sssd: all
        tlog_exclude_users_sssd:
          - jeff
          - james
        tlog_exclude_groups_sssd:
          - admins
    
      roles:
        - rhel-system-roles.tlog

    Where,

    • tlog_scope_sssd:

      • all: specifies that you want to record all users and groups.
    • tlog_exclude_users_sssd:

      • user names: specifies the user names of the users you want to exclude from the session recording.
    • tlog_exclude_groups_sssd:

      • admins specifies the group you want to exclude from the session recording.
  2. Optionally, verify the playbook syntax;

    # ansible-playbook --syntax-check playbook.yml
  3. Run the playbook on your inventory file:

    # ansible-playbook -i IP_Address /path/to/file/playbook.yml -v

As a result, the playbook installs the tlog RHEL System Role on the system you specified. The role includes tlog-rec-session, a terminal session I/O logging program, that acts as the login shell for a user. It also creates an /etc/sssd/conf.d/sssd-session-recording.conf SSSD configuration drop file that can be used by users and groups except those that you defined as excluded. SSSD parses and reads these users and groups, and replaces their user shell with tlog-rec-session. Additionally, if the cockpit package is installed on the system, the playbook also installs the cockpit-session-recording package, which is a Cockpit module that allows you to view and play recordings in the web console interface.

Verification steps

To verify that the SSSD configuration drop file is created in the system, perform the following steps:

  1. Navigate to the folder where the SSSD configuration drop file is created:

    # cd /etc/sssd/conf.d
  2. Check the file content:

    # cat sssd-session-recording.conf

You can see that the file contains the parameters you set in the playbook.

Additional resources

25.5. Recording a session using the deployed tlog System Role in the CLI

After you have deployed the tlog System Role in the system you have specified, you are able to record a user terminal session using the command-line interface (CLI).

Prerequisites

Procedure

  1. Create a user and assign a password for this user:

    # useradd recorded-user
    # passwd recorded-user
  2. Log in to the system as the user you just created:

    # ssh recorded-user@localhost
  3. Type "yes" when the system prompts you to type yes or no to authenticate.
  4. Insert the recorded-user’s password.

    The system displays a message about your session being recorded.

    ATTENTION! Your session is being recorded!
  5. After you have finished recording the session, type:

    # exit

    The system logs out from the user and closes the connection with the localhost.

As a result, the user session is recorded, stored and you can play it using a journal.

Verification steps

To view your recorded session in the journal, do the following steps:

  1. Run the command below:

    # journalctl -o verbose -r
  2. Search for the MESSAGE field of the tlog-rec recorded journal entry.

    # journalctl -xel _EXE=/usr/bin/tlog-rec-session

25.6. Watching a recorded session using the CLI

You can play a user session recording from a journal using the command-line interface (CLI).

Prerequisites

Procedure

  1. On the CLI terminal, play the user session recording:

    # journalctl -o verbose -r
  2. Search for the tlog recording:

    $ /tlog-rec

    You can see details such as:

    • The username for the user session recording
    • The out_txt field, a raw output encode of the recorded session
    • The identifier number TLOG_REC=ID_number
  3. Copy the identifier number TLOG_REC=ID_number.
  4. Playback the recording using the identifier number TLOG_REC=ID_number.

    # tlog-play -r journal -M TLOG_REC=ID_number

As a result, you can see the user session recording terminal output being played back.

Chapter 26. Configuring a high-availability cluster by using the ha_cluster RHEL System Role

With the ha_cluster System Role, you can configure and manage a high-availability cluster that uses the Pacemaker high availability cluster resource manager.

26.1. ha_cluster System Role variables

In an ha_cluster System Role playbook, you define the variables for a high availability cluster according to the requirements of your cluster deployment.

The variables you can set for an ha_cluster System Role are as follows:

ha_cluster_enable_repos
A boolean flag that enables the repositories containing the packages that are needed by the ha_cluster System Role. When this variable is set to true, the default value, you have active subscription coverage for RHEL and the RHEL High Availability Add-On on the systems that you will use as your cluster members or the System Role will fail.
ha_cluster_manage_firewall

(RHEL 8.8 and later) A boolean flag that determines whether the ha_cluster System Role manages the firewall. When ha_cluster_manage_firewall is set to true, the firewall high availability service and the fence-virt port are enabled. When ha_cluster_manage_firewall is set to false, the ha_cluster System Role does not manage the firewall. If your system is running the firewalld service, you must set the parameter to true in your playbook.

You can use the ha_cluster_manage_firewall parameter to add ports, but you cannot use the parameter to remove ports. To remove ports, use the firewall System Role directly.

As of RHEL 8.8, the firewall is no longer configured by default, because it is configured only when ha_cluster_manage_firewall is set to true.

ha_cluster_manage_selinux

(RHEL 8.8 and later) A boolean flag that determines whether the ha_cluster System Role manages the ports belonging to the firewall high availability service using the selinux System Role. When ha_cluster_manage_selinux is set to true, the ports belonging to the firewall high availability service are associated with the SELinux port type cluster_port_t. When ha_cluster_manage_selinux is set to false, the ha_cluster System Role does not manage SELinux.

If your system is running the selinux service, you must set this parameter to true in your playbook. Firewall configuration is a prerequisite for managing SELinux. If the firewall is not installed, the managing SELinux policy is skipped.

You can use the ha_cluster_manage_selinux parameter to add policy, but you cannot use the parameter to remove policy. To remove policy, use the selinux System Role directly.

ha_cluster_cluster_present

A boolean flag which, if set to true, determines that HA cluster will be configured on the hosts according to the variables passed to the role. Any cluster configuration not specified in the role and not supported by the role will be lost.

If ha_cluster_cluster_present is set to false, all HA cluster configuration will be removed from the target hosts.

The default value of this variable is true.

The following example playbook removes all cluster configuration on node1 and node2

- hosts: node1 node2
  vars:
    ha_cluster_cluster_present: false

  roles:
    - rhel-system-roles.ha_cluster
ha_cluster_start_on_boot
A boolean flag that determines whether cluster services will be configured to start on boot. The default value of this variable is true.
ha_cluster_fence_agent_packages
List of fence agent packages to install. The default value of this variable is fence-agents-all, fence-virt.
ha_cluster_extra_packages

List of additional packages to be installed. The default value of this variable is no packages.

This variable can be used to install additional packages not installed automatically by the role, for example custom resource agents.

It is possible to specify fence agents as members of this list. However, ha_cluster_fence_agent_packages is the recommended role variable to use for specifying fence agents, so that its default value is overridden.

ha_cluster_hacluster_password
A string value that specifies the password of the hacluster user. The hacluster user has full access to a cluster. To protect sensitive data, vault encrypt the password, as described in Encrypting content with Ansible Vault. There is no default password value, and this variable must be specified.
ha_cluster_hacluster_qdevice_password
(RHEL 8.9 and later) A string value that specifies the password of the hacluster user for a quorum device. This parameter is needed only if the ha_cluster_quorum parameter is configured to use a quorum device of type net and the password of the hacluster user on the quorum device is different from the password of the hacluster user specified with the ha_cluster_hacluster_password parameter. The hacluster user has full access to a cluster. To protect sensitive data, vault encrypt the password, as described in Encrypting content with Ansible Vault. There is no default value for this password.
ha_cluster_corosync_key_src

The path to Corosync authkey file, which is the authentication and encryption key for Corosync communication. It is highly recommended that you have a unique authkey value for each cluster. The key should be 256 bytes of random data.

If you specify a key for this variable, it is recommended that you vault encrypt the key, as described in Encrypting content with Ansible Vault.

If no key is specified, a key already present on the nodes will be used. If nodes do not have the same key, a key from one node will be distributed to other nodes so that all nodes have the same key. If no node has a key, a new key will be generated and distributed to the nodes.

If this variable is set, ha_cluster_regenerate_keys is ignored for this key.

The default value of this variable is null.

ha_cluster_pacemaker_key_src

The path to the Pacemaker authkey file, which is the authentication and encryption key for Pacemaker communication. It is highly recommended that you have a unique authkey value for each cluster. The key should be 256 bytes of random data.

If you specify a key for this variable, it is recommended that you vault encrypt the key, as described in Encrypting content with Ansible Vault.

If no key is specified, a key already present on the nodes will be used. If nodes do not have the same key, a key from one node will be distributed to other nodes so that all nodes have the same key. If no node has a key, a new key will be generated and distributed to the nodes.

If this variable is set, ha_cluster_regenerate_keys is ignored for this key.

The default value of this variable is null.

ha_cluster_fence_virt_key_src

The path to the fence-virt or fence-xvm pre-shared key file, which is the location of the authentication key for the fence-virt or fence-xvm fence agent.

If you specify a key for this variable, it is recommended that you vault encrypt the key, as described in Encrypting content with Ansible Vault.

If no key is specified, a key already present on the nodes will be used. If nodes do not have the same key, a key from one node will be distributed to other nodes so that all nodes have the same key. If no node has a key, a new key will be generated and distributed to the nodes. If the ha_cluster System Role generates a new key in this fashion, you should copy the key to your nodes' hypervisor to ensure that fencing works.

If this variable is set, ha_cluster_regenerate_keys is ignored for this key.

The default value of this variable is null.

ha_cluster_pcsd_public_key_srcr, ha_cluster_pcsd_private_key_src

The path to the pcsd TLS certificate and private key. If this is not specified, a certificate-key pair already present on the nodes will be used. If a certificate-key pair is not present, a random new one will be generated.

If you specify a private key value for this variable, it is recommended that you vault encrypt the key, as described in Encrypting content with Ansible Vault.

If these variables are set, ha_cluster_regenerate_keys is ignored for this certificate-key pair.

The default value of these variables is null.

ha_cluster_pcsd_certificates

(RHEL 8.8 and later) Creates a pcsd private key and certificate using the certificate System Role.

If your system is not configured with a pcsd private key and certificate, you can create them in one of two ways:

  • Set the ha_cluster_pcsd_certificates variable. When you set the ha_cluster_pcsd_certificates variable, the certificate System Role is used internally and it creates the private key and certificate for pcsd as defined.
  • Do not set the ha_cluster_pcsd_public_key_src, ha_cluster_pcsd_private_key_src, or the ha_cluster_pcsd_certificates variables. If you do not set any of these variables, the ha_cluster System Role will create pcsd certificates by means of pcsd itself. The value of ha_cluster_pcsd_certificates is set to the value of the variable certificate_requests as specified in the certificate System Role. For more information about the certificate System Role, see Requesting certificates using RHEL System Roles.

The following operational considerations apply to the use of the ha_cluster_pcsd_certificate variable:

  • Unless you are using IPA and joining the systems to an IPA domain, the certificate System Role creates self-signed certificates. In this case, you must explicitly configure trust settings outside of the context of RHEL System Roles. System Roles do not support configuring trust settings.
  • When you set the ha_cluster_pcsd_certificates variable, do not set the ha_cluster_pcsd_public_key_src and ha_cluster_pcsd_private_key_src variables.
  • When you set the ha_cluster_pcsd_certificates variable, ha_cluster_regenerate_keys is ignored for this certificate - key pair.

The default value of this variable is [].

For an example ha_cluster System Role playbook that creates TLS certificates and key files in a high availability cluster, see Creating pcsd TLS certificates and key files for a high availability cluster.

ha_cluster_regenerate_keys
A boolean flag which, when set to true, determines that pre-shared keys and TLS certificates will be regenerated. For more information about when keys and certificates will be regenerated, see the descriptions of the ha_cluster_corosync_key_src, ha_cluster_pacemaker_key_src, ha_cluster_fence_virt_key_src, ha_cluster_pcsd_public_key_src, and ha_cluster_pcsd_private_key_src variables.
The default value of this variable is false.
ha_cluster_pcs_permission_list

Configures permissions to manage a cluster using pcsd. The items you configure with this variable are as follows:

  • type - user or group
  • name - user or group name
  • allow_list - Allowed actions for the specified user or group:

    • read - View cluster status and settings
    • write - Modify cluster settings except permissions and ACLs
    • grant - Modify cluster permissions and ACLs
    • full - Unrestricted access to a cluster including adding and removing nodes and access to keys and certificates

The structure of the ha_cluster_pcs_permission_list variable and its default values are as follows:

ha_cluster_pcs_permission_list:
  - type: group
    name: hacluster
    allow_list:
      - grant
      - read
      - write
ha_cluster_cluster_name
The name of the cluster. This is a string value with a default of my-cluster.
ha_cluster_transport

(RHEL 8.7 and later) Sets the cluster transport method. The items you configure with this variable are as follows:

  • type (optional) - Transport type: knet, udp, or udpu. The udp and udpu transport types support only one link. Encryption is always disabled for udp and udpu. Defaults to knet if not specified.
  • options (optional) - List of name-value dictionaries with transport options.
  • links (optional) - List of list of name-value dictionaries. Each list of name-value dictionaries holds options for one Corosync link. It is recommended that you set the linknumber value for each link. Otherwise, the first list of dictionaries is assigned by default to the first link, the second one to the second link, and so on.
  • compression (optional) - List of name-value dictionaries configuring transport compression. Supported only with the knet transport type.
  • crypto (optional) - List of name-value dictionaries configuring transport encryption. By default, encryption is enabled. Supported only with the knet transport type.

For a list of allowed options, see the pcs -h cluster setup help page or the setup description in the cluster section of the pcs(8) man page. For more detailed descriptions, see the corosync.conf(5) man page.

The structure of the ha_cluster_transport variable is as follows:

ha_cluster_transport:
  type: knet
  options:
    - name: option1_name
      value: option1_value
    - name: option2_name
      value: option2_value
  links:
    -
      - name: option1_name
        value: option1_value
      - name: option2_name
        value: option2_value
    -
      - name: option1_name
        value: option1_value
      - name: option2_name
        value: option2_value
  compression:
    - name: option1_name
      value: option1_value
    - name: option2_name
      value: option2_value
  crypto:
    - name: option1_name
      value: option1_value
    - name: option2_name
      value: option2_value

For an example ha_cluster System Role playbook that configures a transport method, see Configuring Corosync values in a high availability cluster.

ha_cluster_totem

(RHEL 8.7 and later) Configures Corosync totem. For a list of allowed options, see the pcs -h cluster setup help page or the setup description in the cluster section of the pcs(8) man page. For a more detailed description, see the corosync.conf(5) man page.

The structure of the ha_cluster_totem variable is as follows:

ha_cluster_totem:
  options:
    - name: option1_name
      value: option1_value
    - name: option2_name
      value: option2_value

For an example ha_cluster System Role playbook that configures a Corosync totem, see Configuring Corosync values in a high availability cluster.

ha_cluster_quorum

(RHEL 8.7 and later) Configures cluster quorum. You can configure the following items for cluster quorum:

  • options (optional) - List of name-value dictionaries configuring quorum. Allowed options are: auto_tie_breaker, last_man_standing, last_man_standing_window, and wait_for_all. For information about quorum options, see the votequorum(5) man page.
  • device (optional) - (RHEL 8.8 and later) Configures the cluster to use a quorum device. By default, no quorum device is used.

    • model (mandatory) - Specifies a quorum device model. Only net is supported
    • model_options (optional) - List of name-value dictionaries configuring the specified quorum device model. For model net, you must specify host and algorithm options.

      Use the pcs-address option to set a custom pcsd address and port to connect to the qnetd host. If you do not specify this option, the role connects to the default pcsd port on the host.

    • generic_options (optional) - List of name-value dictionaries setting quorum device options that are not model specific.
    • heuristics_options (optional) - List of name-value dictionaries configuring quorum device heuristics.

      For information about quorum device options, see the corosync-qdevice(8) man page. The generic options are sync_timeout and timeout. For model net options see the quorum.device.net section. For heuristics options, see the quorum.device.heuristics section.

      To regenerate a quorum device TLS certificate, set the ha_cluster_regenerate_keys variable to true.

The structure of the ha_cluster_quorum variable is as follows:

ha_cluster_quorum:
  options:
    - name: option1_name
      value: option1_value
    - name: option2_name
      value: option2_value
  device:
    model: string
    model_options:
      - name: option1_name
        value: option1_value
      - name: option2_name
        value: option2_value
    generic_options:
      - name: option1_name
        value: option1_value
      - name: option2_name
        value: option2_value
    heuristics_options:
      - name: option1_name
        value: option1_value
      - name: option2_name
        value: option2_value

For an example ha_cluster System Role playbook that configures cluster quorum, see Configuring Corosync values in a high availability cluster. For an example ha_cluster System Role playbook that configures a cluster using a quorum device, see Configuring a high availability cluster using a quorum device.

ha_cluster_sbd_enabled

(RHEL 8.7 and later) A boolean flag which determines whether the cluster can use the SBD node fencing mechanism. The default value of this variable is false.

For an example ha_cluster System Role playbook that enables SBD, see Configuring a high availability cluster with SBD node fencing.

ha_cluster_sbd_options

(RHEL 8.7 and later) List of name-value dictionaries specifying SBD options. Supported options are:

  • delay-start - defaults to no
  • startmode - defaults to always
  • timeout-action - defaults to flush,reboot
  • watchdog-timeout - defaults to 5

    For information about these options, see the Configuration via environment section of the sbd(8) man page.

For an example ha_cluster System Role playbook that configures SBD options, see Configuring a high availability cluster with SBD node fencing.

When using SBD, you can optionally configure watchdog and SBD devices for each node in an inventory. For information about configuring watchdog and SBD devices in an inventory file, see Specifying an inventory for the ha_cluster System Role.

ha_cluster_cluster_properties

List of sets of cluster properties for Pacemaker cluster-wide configuration. Only one set of cluster properties is supported.

The structure of a set of cluster properties is as follows:

ha_cluster_cluster_properties:
  - attrs:
      - name: property1_name
        value: property1_value
      - name: property2_name
        value: property2_value

By default, no properties are set.

The following example playbook configures a cluster consisting of node1 and node2 and sets the stonith-enabled and no-quorum-policy cluster properties.

- hosts: node1 node2
  vars:
    ha_cluster_cluster_name: my-new-cluster
    ha_cluster_hacluster_password: password
    ha_cluster_cluster_properties:
      - attrs:
          - name: stonith-enabled
            value: 'true'
          - name: no-quorum-policy
            value: stop

  roles:
    - rhel-system-roles.ha_cluster
ha_cluster_resource_primitives

This variable defines pacemaker resources configured by the System Role, including stonith resources, including stonith resources. You can configure the following items for each resource:

  • id (mandatory) - ID of a resource.
  • agent (mandatory) - Name of a resource or stonith agent, for example ocf:pacemaker:Dummy or stonith:fence_xvm. It is mandatory to specify stonith: for stonith agents. For resource agents, it is possible to use a short name, such as Dummy, instead of ocf:pacemaker:Dummy. However, if several agents with the same short name are installed, the role will fail as it will be unable to decide which agent should be used. Therefore, it is recommended that you use full names when specifying a resource agent.
  • instance_attrs (optional) - List of sets of the resource’s instance attributes. Currently, only one set is supported. The exact names and values of attributes, as well as whether they are mandatory or not, depend on the resource or stonith agent.
  • meta_attrs (optional) - List of sets of the resource’s meta attributes. Currently, only one set is supported.
  • copy_operations_from_agent (optional) - (RHEL 8.9 and later) Resource agents usually define default settings for resource operations, such as interval and timeout, optimized for the specific agent. If this variable is set to true, then those settings are copied to the resource configuration. Otherwise, clusterwide defaults apply to the resource. If you also define resource operation defaults for the resource with the ha_cluster_resource_operation_defaults role variable, you can set this to false. The default value of this variable is true.
  • operations (optional) - List of the resource’s operations.

    • action (mandatory) - Operation action as defined by pacemaker and the resource or stonith agent.
    • attrs (mandatory) - Operation options, at least one option must be specified.

The structure of the resource definition that you configure with the ha_cluster System Role is as follows:

  - id: resource-id
    agent: resource-agent
    instance_attrs:
      - attrs:
          - name: attribute1_name
            value: attribute1_value
          - name: attribute2_name
            value: attribute2_value
    meta_attrs:
      - attrs:
          - name: meta_attribute1_name
            value: meta_attribute1_value
          - name: meta_attribute2_name
            value: meta_attribute2_value
    copy_operations_from_agent: bool
    operations:
      - action: operation1-action
        attrs:
          - name: operation1_attribute1_name
            value: operation1_attribute1_value
          - name: operation1_attribute2_name
            value: operation1_attribute2_value
      - action: operation2-action
        attrs:
          - name: operation2_attribute1_name
            value: operation2_attribute1_value
          - name: operation2_attribute2_name
            value: operation2_attribute2_value

By default, no resources are defined.

For an example ha_cluster System Role playbook that includes resource configuration, see Configuring a high availability cluster with fencing and resources.

ha_cluster_resource_groups

This variable defines pacemaker resource groups configured by the System Role. You can configure the following items for each resource group:

  • id (mandatory) - ID of a group.
  • resources (mandatory) - List of the group’s resources. Each resource is referenced by its ID and the resources must be defined in the ha_cluster_resource_primitives variable. At least one resource must be listed.
  • meta_attrs (optional) - List of sets of the group’s meta attributes. Currently, only one set is supported.

The structure of the resource group definition that you configure with the ha_cluster System Role is as follows:

ha_cluster_resource_groups:
  - id: group-id
    resource_ids:
      - resource1-id
      - resource2-id
    meta_attrs:
      - attrs:
          - name: group_meta_attribute1_name
            value: group_meta_attribute1_value
          - name: group_meta_attribute2_name
            value: group_meta_attribute2_value

By default, no resource groups are defined.

For an example ha_cluster System Role playbook that includes resource group configuration, see Configuring a high availability cluster with fencing and resources.

ha_cluster_resource_clones

This variable defines pacemaker resource clones configured by the System Role. You can configure the following items for a resource clone:

  • resource_id (mandatory) - Resource to be cloned. The resource must be defined in the ha_cluster_resource_primitives variable or the ha_cluster_resource_groups variable.
  • promotable (optional) - Indicates whether the resource clone to be created is a promotable clone, indicated as true or false.
  • id (optional) - Custom ID of the clone. If no ID is specified, it will be generated. A warning will be displayed if this option is not supported by the cluster.
  • meta_attrs (optional) - List of sets of the clone’s meta attributes. Currently, only one set is supported.

The structure of the resource clone definition that you configure with the ha_cluster System Role is as follows:

ha_cluster_resource_clones:
  - resource_id: resource-to-be-cloned
    promotable: true
    id: custom-clone-id
    meta_attrs:
      - attrs:
          - name: clone_meta_attribute1_name
            value: clone_meta_attribute1_value
          - name: clone_meta_attribute2_name
            value: clone_meta_attribute2_value

By default, no resource clones are defined.

For an example ha_cluster System Role playbook that includes resource clone configuration, see Configuring a high availability cluster with fencing and resources.

ha_cluster_resource_defaults

(RHEL 8.9 and later) This variable defines sets of resource defaults. You can define multiple sets of defaults and apply them to resources of specific agents using rules. The defaults you specify with the ha_cluster_resource_defaults variable do not apply to resources which override them with their own defined values.

Only meta attributes can be specified as defaults.

You can configure the following items for each defaults set:

  • id (optional) - ID of the defaults set. If not specified, it is autogenerated.
  • rule (optional) - Rule written using pcs syntax defining when and for which resources the set applies. For information on specifying a rule, see the resource defaults set create section of the pcs(8) man page.
  • score (optional) - Weight of the defaults set.
  • attrs (optional) - Meta attributes applied to resources as defaults.

The structure of the ha_cluster_resource_defaults variable is as follows:

ha_cluster_resource_defaults:
  meta_attrs:
    - id: defaults-set-1-id
      rule: rule-string
      score: score-value
      attrs:
        - name: meta_attribute1_name
          value: meta_attribute1_value
        - name: meta_attribute2_name
          value: meta_attribute2_value
    - id: defaults-set-2-id
      rule: rule-string
      score: score-value
      attrs:
        - name: meta_attribute3_name
          value: meta_attribute3_value
        - name: meta_attribute4_name
          value: meta_attribute4_value

For an example ha_cluster System Role playbook that configures resource defaults, see Configuring a high availability cluster with resource and resource operation defaults.

ha_cluster_resource_operation_defaults

(RHEL 8.9 and later) This variable defines sets of resource operation defaults. You can define multiple sets of defaults and apply them to resources of specific agents and specific resource operations using rules. The defaults you specify with the ha_cluster_resource_operation_defaults variable do not apply to resource operations which override them with their own defined values. By default, the ha_cluster System Role configures resources to define their own values for resource operations. For information about overriding these defaults with the ha_cluster_resource_operations_defaults variable, see the description of the copy_operations_from_agent item in ha_cluster_resource_primitives.

Only meta attributes can be specified as defaults.

The structure of the ha_cluster_resource_operations_defaults variable is the same as the structure for the ha_cluster_resource_defaults variable, with the exception of how you specify a rule. For information about specifying a rule to describe the resource operation to which a set applies, see the resource op defaults set create section of the pcs(8) man page.

ha_cluster_constraints_location

This variable defines resource location constraints. Resource location constraints indicate which nodes a resource can run on. You can specify a resources specified by a resource ID or by a pattern, which can match more than one resource. You can specify a node by a node name or by a rule.

You can configure the following items for a resource location constraint:

  • resource (mandatory) - Specification of a resource the constraint applies to.
  • node (mandatory) - Name of a node the resource should prefer or avoid.
  • id (optional) - ID of the constraint. If not specified, it will be autogenerated.
  • options (optional) - List of name-value dictionaries.

    • score - Sets the weight of the constraint.

      • A positive score value means the resource prefers running on the node.
      • A negative score value means the resource should avoid running on the node.
      • A score value of -INFINITY means the resource must avoid running on the node.
      • If score is not specified, the score value defaults to INFINITY.

By default no resource location constraints are defined.

The structure of a resource location constraint specifying a resource ID and node name is as follows:

ha_cluster_constraints_location:
  - resource:
      id: resource-id
    node: node-name
    id: constraint-id
    options:
      - name: score
        value: score-value
      - name: option-name
        value: option-value

The items that you configure for a resource location constraint that specifies a resource pattern are the same items that you configure for a resource location constraint that specifies a resource ID, with the exception of the resource specification itself. The item that you specify for the resource specification is as follows:

  • pattern (mandatory) - POSIX extended regular expression resource IDs are matched against.

The structure of a resource location constraint specifying a resource pattern and node name is as follows:

ha_cluster_constraints_location:
  - resource:
      pattern: resource-pattern
    node: node-name
    id: constraint-id
    options:
      - name: score
        value: score-value
      - name: resource-discovery
        value: resource-discovery-value

You can configure the following items for a resource location constraint that specifies a resource ID and a rule:

  • resource (mandatory) - Specification of a resource the constraint applies to.

    • id (mandatory) - Resource ID.
    • role (optional) - The resource role to which the constraint is limited: Started, Unpromoted, Promoted.
  • rule (mandatory) - Constraint rule written using pcs syntax. For further information, see the constraint location section of the pcs(8) man page.
  • Other items to specify have the same meaning as for a resource constraint that does not specify a rule.

The structure of a resource location constraint that specifies a resource ID and a rule is as follows:

ha_cluster_constraints_location:
  - resource:
      id: resource-id
      role: resource-role
    rule: rule-string
    id: constraint-id
    options:
      - name: score
        value: score-value
      - name: resource-discovery
        value: resource-discovery-value

The items that you configure for a resource location constraint that specifies a resource pattern and a rule are the same items that you configure for a resource location constraint that specifies a resource ID and a rule, with the exception of the resource specification itself. The item that you specify for the resource specification is as follows:

  • pattern (mandatory) - POSIX extended regular expression resource IDs are matched against.

The structure of a resource location constraint that specifies a resource pattern and a rule is as follows:

ha_cluster_constraints_location:
  - resource:
      pattern: resource-pattern
      role: resource-role
    rule: rule-string
    id: constraint-id
    options:
      - name: score
        value: score-value
      - name: resource-discovery
        value: resource-discovery-value

For an example ha_cluster System Role playbook that creates a cluster with resource constraints, see Configuring a high availability cluster with resource constraints.

ha_cluster_constraints_colocation

This variable defines resource colocation constraints. Resource colocation constraints indicate that the location of one resource depends on the location of another one. There are two types of colocation constraints: a simple colocation constraint for two resources, and a set colocation constraint for multiple resources.

You can configure the following items for a simple resource colocation constraint:

  • resource_follower (mandatory) - A resource that should be located relative to resource_leader.

    • id (mandatory) - Resource ID.
    • role (optional) - The resource role to which the constraint is limited: Started, Unpromoted, Promoted.
  • resource_leader (mandatory) - The cluster will decide where to put this resource first and then decide where to put resource_follower.

    • id (mandatory) - Resource ID.
    • role (optional) - The resource role to which the constraint is limited: Started, Unpromoted, Promoted.
  • id (optional) - ID of the constraint. If not specified, it will be autogenerated.
  • options (optional) - List of name-value dictionaries.

    • score - Sets the weight of the constraint.

      • Positive score values indicate the resources should run on the same node.
      • Negative score values indicate the resources should run on different nodes.
      • A score value of +INFINITY indicates the resources must run on the same node.
      • A score value of -INFINITY indicates the resources must run on different nodes.
      • If score is not specified, the score value defaults to INFINITY.

By default no resource colocation constraints are defined.

The structure of a simple resource colocation constraint is as follows:

ha_cluster_constraints_colocation:
  - resource_follower:
      id: resource-id1
      role: resource-role1
    resource_leader:
      id: resource-id2
      role: resource-role2
    id: constraint-id
    options:
      - name: score
        value: score-value
      - name: option-name
        value: option-value

You can configure the following items for a resource set colocation constraint:

  • resource_sets (mandatory) - List of resource sets.

    • resource_ids (mandatory) - List of resources in a set.
    • options (optional) - List of name-value dictionaries fine-tuning how resources in the sets are treated by the constraint.
  • id (optional) - Same values as for a simple colocation constraint.
  • options (optional) - Same values as for a simple colocation constraint.

The structure of a resource set colocation constraint is as follows:

ha_cluster_constraints_colocation:
  - resource_sets:
      - resource_ids:
          - resource-id1
          - resource-id2
        options:
          - name: option-name
            value: option-value
    id: constraint-id
    options:
      - name: score
        value: score-value
      - name: option-name
        value: option-value

For an example ha_cluster System Role playbook that creates a cluster with resource constraints, see Configuring a high availability cluster with resource constraints.

ha_cluster_constraints_order

This variable defines resource order constraints. Resource order constraints indicate the order in which certain resource actions should occur. There are two types of resource order constraints: a simple order constraint for two resources, and a set order constraint for multiple resources.

You can configure the following items for a simple resource order constraint:

  • resource_first (mandatory) - Resource that the resource_then resource depends on.

    • id (mandatory) - Resource ID.
    • action (optional) - The action that must complete before an action can be initiated for the resource_then resource. Allowed values: start, stop, promote, demote.
  • resource_then (mandatory) - The dependent resource.

    • id (mandatory) - Resource ID.
    • action (optional) - The action that the resource can execute only after the action on the resource_first resource has completed. Allowed values: start, stop, promote, demote.
  • id (optional) - ID of the constraint. If not specified, it will be autogenerated.
  • options (optional) - List of name-value dictionaries.

By default no resource order constraints are defined.

The structure of a simple resource order constraint is as follows:

ha_cluster_constraints_order:
  - resource_first:
      id: resource-id1
      action: resource-action1
    resource_then:
      id: resource-id2
      action: resource-action2
    id: constraint-id
    options:
      - name: score
        value: score-value
      - name: option-name
        value: option-value

You can configure the following items for a resource set order constraint:

  • resource_sets (mandatory) - List of resource sets.

    • resource_ids (mandatory) - List of resources in a set.
    • options (optional) - List of name-value dictionaries fine-tuning how resources in the sets are treated by the constraint.
  • id (optional) - Same values as for a simple order constraint.
  • options (optional) - Same values as for a simple order constraint.

The structure of a resource set order constraint is as follows:

ha_cluster_constraints_order:
  - resource_sets:
      - resource_ids:
          - resource-id1
          - resource-id2
        options:
          - name: option-name
            value: option-value
    id: constraint-id
    options:
      - name: score
        value: score-value
      - name: option-name
        value: option-value

For an example ha_cluster System Role playbook that creates a cluster with resource constraints, see Configuring a high availability cluster with resource constraints.

ha_cluster_constraints_ticket

This variable defines resource ticket constraints. Resource ticket constraints indicate the resources that depend on a certain ticket. There are two types of resource ticket constraints: a simple ticket constraint for one resource, and a ticket order constraint for multiple resources.

You can configure the following items for a simple resource ticket constraint:

  • resource (mandatory) - Specification of a resource the constraint applies to.

    • id (mandatory) - Resource ID.
    • role (optional) - The resource role to which the constraint is limited: Started, Unpromoted, Promoted.
  • ticket (mandatory) - Name of a ticket the resource depends on.
  • id (optional) - ID of the constraint. If not specified, it will be autogenerated.
  • options (optional) - List of name-value dictionaries.

    • loss-policy (optional) - Action to perform on the resource if the ticket is revoked.

By default no resource ticket constraints are defined.

The structure of a simple resource ticket constraint is as follows:

ha_cluster_constraints_ticket:
  - resource:
      id: resource-id
      role: resource-role
    ticket: ticket-name
    id: constraint-id
    options:
      - name: loss-policy
        value: loss-policy-value
      - name: option-name
        value: option-value

You can configure the following items for a resource set ticket constraint:

  • resource_sets (mandatory) - List of resource sets.

    • resource_ids (mandatory) - List of resources in a set.
    • options (optional) - List of name-value dictionaries fine-tuning how resources in the sets are treated by the constraint.
  • ticket (mandatory) - Same value as for a simple ticket constraint.
  • id (optional) - Same value as for a simple ticket constraint.
  • options (optional) - Same values as for a simple ticket constraint.

The structure of a resource set ticket constraint is as follows:

ha_cluster_constraints_ticket:
  - resource_sets:
      - resource_ids:
          - resource-id1
          - resource-id2
        options:
          - name: option-name
            value: option-value
    ticket: ticket-name
    id: constraint-id
    options:
      - name: option-name
        value: option-value

For an example ha_cluster System Role playbook that creates a cluster with resource constraints, see Configuring a high availability cluster with resource constraints.

ha_cluster_qnetd

(RHEL 8.8 and later) This variable configures a qnetd host which can then serve as an external quorum device for clusters.

You can configure the following items for a qnetd host:

  • present (optional) - If true, configure a qnetd instance on the host. If false, remove qnetd configuration from the host. The default value is false. If you set this true, you must set ha_cluster_cluster_present to false.
  • start_on_boot (optional) - Configures whether the qnetd instance should start automatically on boot. The default value is true.
  • regenerate_keys (optional) - Set this variable to true to regenerate the qnetd TLS certificate. If you regenerate the certificate, you must either re-run the role for each cluster to connect it to the qnetd host again or run pcs manually.

You cannot run qnetd on a cluster node because fencing would disrupt qnetd operation.

For an example ha_cluster System Role playbook that configures a cluster using a quorum device, see Configuring a cluster using a quorum device.

26.2. Specifying an inventory for the ha_cluster System Role

When configuring an HA cluster using the ha_cluster System Role playbook, you configure the names and addresses of the nodes for the cluster in an inventory.

26.2.1. Configuring node names and addresses in an inventory

For each node in an inventory, you can optionally specify the following items:

  • node_name - the name of a node in a cluster.
  • pcs_address - an address used by pcs to communicate with the node. It can be a name, FQDN or an IP address and it can include a port number.
  • corosync_addresses - list of addresses used by Corosync. All nodes which form a particular cluster must have the same number of addresses and the order of the addresses matters.

The following example shows an inventory with targets node1 and node2. node1 and node2 must be either fully qualified domain names or must otherwise be able to connect to the nodes as when, for example, the names are resolvable through the /etc/hosts file.

all:
  hosts:
    node1:
      ha_cluster:
        node_name: node-A
        pcs_address: node1-address
        corosync_addresses:
          - 192.168.1.11
          - 192.168.2.11
    node2:
      ha_cluster:
        node_name: node-B
        pcs_address: node2-address:2224
        corosync_addresses:
          - 192.168.1.12
          - 192.168.2.12

26.2.2. Configuring watchdog and SBD devices in an inventory

(RHEL 8.7 and later) When using SBD, you can optionally configure watchdog and SBD devices for each node in an inventory. Even though all SBD devices must be shared to and accessible from all nodes, each node can use different names for the devices. Watchdog devices can be different for each node as well. For information about the SBD variables you can set in a System Role playbook, see the entries for ha_cluster_sbd_enabled and ha_cluster_sbd_options in ha_cluster System Role variables.

For each node in an inventory, you can optionally specify the following items:

  • sbd_watchdog_modules (optional) - (RHEL 8.9 and later) Watchdog kernel modules to be loaded, which create /dev/watchdog* devices. Defaults to empty list if not set.
  • sbd_watchdog_modules_blocklist (optional) - (RHEL 8.9 and later) Watchdog kernel modules to be unloaded and blocked. Defaults to empty list if not set.
  • sbd_watchdog - Watchdog device to be used by SBD. Defaults to /dev/watchdog if not set.
  • sbd_devices - Devices to use for exchanging SBD messages and for monitoring. Defaults to empty list if not set.

The following example shows an inventory that configures watchdog and SBD devices for targets node1 and node2.

all:
  hosts:
    node1:
      ha_cluster:
        sbd_watchdog_modules:
          - module1
          - module2
        sbd_watchdog: /dev/watchdog2
        sbd_devices:
          - /dev/vdx
          - /dev/vdy
    node2:
      ha_cluster:
        sbd_watchdog_modules:
          - module1
        sbd_watchdog_modules_blocklist:
          - module2
        sbd_watchdog: /dev/watchdog1
        sbd_devices:
          - /dev/vdw
          - /dev/vdz

For information about creating a high availability cluster that uses SBD fencing, see Configuring a high availability cluster with SBD node fencing.

26.3. Creating pcsd TLS certificates and key files for a high availability cluster (RHEL 8.8 and later)

You can use the ha_cluster System Role to create TLS certificates and key files in a high availability cluster. When you run this playbook, the ha_cluster System Role uses the certificate System Role internally to manage TLS certificates.

Prerequisites

  • The ansible-core and the rhel-system-roles packages are installed on the node from which you want to run the playbook.

    Note

    You do not need to have ansible-core installed on the cluster member nodes.

  • The systems that you will use as your cluster members have active subscription coverage for RHEL and the RHEL High Availability Add-On.
Warning

The ha_cluster System Role replaces any existing cluster configuration on the specified nodes. Any settings not specified in the role will be lost.

Procedure

  1. Create an inventory file specifying the nodes in the cluster, as described in Specifying an inventory for the ha_cluster System Role.
  2. Create a playbook file, for example new-cluster.yml.

    Note

    When creating your playbook file for production, vault encrypt the password, as described in Encrypting content with Ansible Vault.

    The following example playbook file configures a cluster running the firewalld and selinux services and creates a self-signed pcsd certificate and private key files in /var/lib/pcsd. The pcsd certificate has the file name FILENAME.crt and the key file is named FILENAME.key.

    - hosts: node1 node2
      vars:
        ha_cluster_cluster_name: my-new-cluster
        ha_cluster_hacluster_password: password
        ha_cluster_manage_firewall: true
        ha_cluster_manage_selinux: true
        ha_cluster_pcsd_certificates:
          - name: FILENAME
            common_name: "{{ ansible_hostname }}"
            ca: self-sign
      roles:
        - linux-system-roles.ha_cluster
  3. Save the file.
  4. Run the playbook, specifying the path to the inventory file inventory you created in Step 1.

    # ansible-playbook -i inventory new-cluster.yml

26.4. Configuring a high availability cluster running no resources

The following procedure uses the ha_cluster System Role, to create a high availability cluster with no fencing configured and which runs no resources.

Prerequisites

  • You have ansible-core installed on the node from which you want to run the playbook.

    Note

    You do not need to have ansible-core installed on the cluster member nodes.

  • You have the rhel-system-roles package installed on the system from which you want to run the playbook.
  • The systems that you will use as your cluster members have active subscription coverage for RHEL and the RHEL High Availability Add-On.
Warning

The ha_cluster System Role replaces any existing cluster configuration on the specified nodes. Any settings not specified in the role will be lost.

Procedure

  1. Create an inventory file specifying the nodes in the cluster, as described in Specifying an inventory for the ha_cluster System Role.
  2. Create a playbook file, for example new-cluster.yml.

    Note

    When creating your playbook file for production, vault encrypt the password, as described in Encrypting content with Ansible Vault.

    The following example playbook file configures a cluster running the firewalld and selinux services with no fencing configured and which runs no resources.

    - hosts: node1 node2
      vars:
        ha_cluster_cluster_name: my-new-cluster
        ha_cluster_hacluster_password: password
        ha_cluster_manage_firewall: true
        ha_cluster_manage_selinux: true
    
      roles:
        - rhel-system-roles.ha_cluster
  3. Save the file.
  4. Run the playbook, specifying the path to the inventory file inventory you created in Step 1.

    # ansible-playbook -i inventory new-cluster.yml

26.5. Configuring a high availability cluster with fencing and resources

The following procedure uses the ha_cluster System Role to create a high availability cluster that includes a fencing device, cluster resources, resource groups, and a cloned resource.

Prerequisites

  • You have ansible-core installed on the node from which you want to run the playbook.

    Note

    You do not need to have ansible-core installed on the cluster member nodes.

  • You have the rhel-system-roles package installed on the system from which you want to run the playbook.
  • The systems that you will use as your cluster members have active subscription coverage for RHEL and the RHEL High Availability Add-On.
Warning

The ha_cluster System Role replaces any existing cluster configuration on the specified nodes. Any settings not specified in the role will be lost.

Procedure

  1. Create an inventory file specifying the nodes in the cluster, as described in Specifying an inventory for the ha_cluster System Role.
  2. Create a playbook file, for example new-cluster.yml.

    Note

    When creating your playbook file for production, vault encrypt the password, as described in Encrypting content with Ansible Vault.

    The following example playbook file configures a cluster running the firewalld and selinux services. The cluster includes fencing, several resources, and a resource group. It also includes a resource clone for the resource group.

    - hosts: node1 node2
      vars:
        ha_cluster_cluster_name: my-new-cluster
        ha_cluster_hacluster_password: password
        ha_cluster_manage_firewall: true
        ha_cluster_manage_selinux: true
        ha_cluster_resource_primitives:
          - id: xvm-fencing
            agent: 'stonith:fence_xvm'
            instance_attrs:
              - attrs:
                  - name: pcmk_host_list
                    value: node1 node2
          - id: simple-resource
            agent: 'ocf:pacemaker:Dummy'
          - id: resource-with-options
            agent: 'ocf:pacemaker:Dummy'
            instance_attrs:
              - attrs:
                  - name: fake
                    value: fake-value
                  - name: passwd
                    value: passwd-value
            meta_attrs:
              - attrs:
                  - name: target-role
                    value: Started
                  - name: is-managed
                    value: 'true'
            operations:
              - action: start
                attrs:
                  - name: timeout
                    value: '30s'
              - action: monitor
                attrs:
                  - name: timeout
                    value: '5'
                  - name: interval
                    value: '1min'
          - id: dummy-1
            agent: 'ocf:pacemaker:Dummy'
          - id: dummy-2
            agent: 'ocf:pacemaker:Dummy'
          - id: dummy-3
            agent: 'ocf:pacemaker:Dummy'
          - id: simple-clone
            agent: 'ocf:pacemaker:Dummy'
          - id: clone-with-options
            agent: 'ocf:pacemaker:Dummy'
        ha_cluster_resource_groups:
          - id: simple-group
            resource_ids:
              - dummy-1
              - dummy-2
            meta_attrs:
              - attrs:
                  - name: target-role
                    value: Started
                  - name: is-managed
                    value: 'true'
          - id: cloned-group
            resource_ids:
              - dummy-3
        ha_cluster_resource_clones:
          - resource_id: simple-clone
          - resource_id: clone-with-options
            promotable: yes
            id: custom-clone-id
            meta_attrs:
              - attrs:
                  - name: clone-max
                    value: '2'
                  - name: clone-node-max
                    value: '1'
          - resource_id: cloned-group
            promotable: yes
    
      roles:
        - rhel-system-roles.ha_cluster
  3. Save the file.
  4. Run the playbook, specifying the path to the inventory file inventory you created in Step 1.

    # ansible-playbook -i inventory new-cluster.yml

26.6. Configuring a high availability cluster with resource and resource operation defaults

(RHEL 8.9 and later) The following procedure uses the ha_cluster System Role to create a high availability cluster that defines resource and resource operation defaults.

Prerequisites

  • You have ansible-core installed on the node from which you want to run the playbook.

    Note

    You do not need to have ansible-core installed on the cluster member nodes.

  • You have the rhel-system-roles package installed on the system from which you want to run the playbook.
  • The systems that you will use as your cluster members have active subscription coverage for RHEL and the RHEL High Availability Add-On.
Warning

The ha_cluster System Role replaces any existing cluster configuration on the specified nodes. Any settings not specified in the role will be lost.

Procedure

  1. Create an inventory file specifying the nodes in the cluster, as described in Specifying an inventory for the ha_cluster System Role.
  2. Create a playbook file, for example new-cluster.yml.

    Note

    When creating your playbook file for production, vault encrypt the password, as described in Encrypting content with Ansible Vault.

    The following example playbook file configures a cluster running the firewalld and selinux services. The cluster includes resource and resource operation defaults.

    - hosts: node1 node2
      vars:
        ha_cluster_cluster_name: my-new-cluster
        ha_cluster_hacluster_password: password
        # Set a different `resource-stickiness` value during
        # and outside work hours. This allows resources to
        # automatically move back to their most
        # preferred hosts, but at a time that
        # does not interfere with business activities.
        ha_cluster_resource_defaults:
          meta_attrs:
            - id: core-hours
              rule: date-spec hours=9-16 weekdays=1-5
              score: 2
              attrs:
                - name: resource-stickiness
                  value: INFINITY
            - id: after-hours
              score: 1
              attrs:
                - name: resource-stickiness
                  value: 0
        # Default the timeout on all 10-second-interval
        # monitor actions on IPaddr2 resources to 8 seconds.
        ha_cluster_resource_operation_defaults:
          meta_attrs:
            - rule: resource ::IPaddr2 and op monitor interval=10s
              score: INFINITY
              attrs:
                - name: timeout
                  value: 8s
      roles:
        - linux-system-roles.ha_cluster
  3. Save the file.
  4. Run the playbook, specifying the path to the inventory file inventory you created in Step 1.

    # ansible-playbook -i inventory new-cluster.yml

26.7. Configuring a high availability cluster with resource constraints

The following procedure uses the ha_cluster System Role to create a high availability cluster that includes resource location constraints, resource colocation constraints, resource order constraints, and resource ticket constraints.

Prerequisites

  • You have ansible-core installed on the node from which you want to run the playbook.

    Note

    You do not need to have ansible-core installed on the cluster member nodes.

  • You have the rhel-system-roles package installed on the system from which you want to run the playbook.
  • The systems that you will use as your cluster members have active subscription coverage for RHEL and the RHEL High Availability Add-On.
Warning

The ha_cluster System Role replaces any existing cluster configuration on the specified nodes. Any settings not specified in the role will be lost.

Procedure

  1. Create an inventory file specifying the nodes in the cluster, as described in Specifying an inventory for the ha_cluster System Role.
  2. Create a playbook file, for example new-cluster.yml.

    Note

    When creating your playbook file for production, vault encrypt the password, as described in Encrypting content with Ansible Vault.

    The following example playbook file configures a cluster running the firewalld and selinux services. The cluster includes resource location constraints, resource colocation constraints, resource order constraints, and resource ticket constraints.

    - hosts: node1 node2
      vars:
        ha_cluster_cluster_name: my-new-cluster
        ha_cluster_hacluster_password: password
        ha_cluster_manage_firewall: true
        ha_cluster_manage_selinux: true
        # In order to use constraints, we need resources the constraints will apply
        # to.
        ha_cluster_resource_primitives:
          - id: xvm-fencing
            agent: 'stonith:fence_xvm'
            instance_attrs:
              - attrs:
                  - name: pcmk_host_list
                    value: node1 node2
          - id: dummy-1
            agent: 'ocf:pacemaker:Dummy'
          - id: dummy-2
            agent: 'ocf:pacemaker:Dummy'
          - id: dummy-3
            agent: 'ocf:pacemaker:Dummy'
          - id: dummy-4
            agent: 'ocf:pacemaker:Dummy'
          - id: dummy-5
            agent: 'ocf:pacemaker:Dummy'
          - id: dummy-6
            agent: 'ocf:pacemaker:Dummy'
        # location constraints
        ha_cluster_constraints_location:
          # resource ID and node name
          - resource:
              id: dummy-1
            node: node1
            options:
              - name: score
                value: 20
          # resource pattern and node name
          - resource:
              pattern: dummy-\d+
            node: node1
            options:
              - name: score
                value: 10
          # resource ID and rule
          - resource:
              id: dummy-2
            rule: '#uname eq node2 and date in_range 2022-01-01 to 2022-02-28'
          # resource pattern and rule
          - resource:
              pattern: dummy-\d+
            rule: node-type eq weekend and date-spec weekdays=6-7
        # colocation constraints
        ha_cluster_constraints_colocation:
          # simple constraint
          - resource_leader:
              id: dummy-3
            resource_follower:
              id: dummy-4
            options:
              - name: score
                value: -5
          # set constraint
          - resource_sets:
              - resource_ids:
                  - dummy-1
                  - dummy-2
              - resource_ids:
                  - dummy-5
                  - dummy-6
                options:
                  - name: sequential
                    value: "false"
            options:
              - name: score
                value: 20
        # order constraints
        ha_cluster_constraints_order:
          # simple constraint
          - resource_first:
              id: dummy-1
            resource_then:
              id: dummy-6
            options:
              - name: symmetrical
                value: "false"
          # set constraint
          - resource_sets:
              - resource_ids:
                  - dummy-1
                  - dummy-2
                options:
                  - name: require-all
                    value: "false"
                  - name: sequential
                    value: "false"
              - resource_ids:
                  - dummy-3
              - resource_ids:
                  - dummy-4
                  - dummy-5
                options:
                  - name: sequential
                    value: "false"
        # ticket constraints
        ha_cluster_constraints_ticket:
          # simple constraint
          - resource:
              id: dummy-1
            ticket: ticket1
            options:
              - name: loss-policy
                value: stop
          # set constraint
          - resource_sets:
              - resource_ids:
                  - dummy-3
                  - dummy-4
                  - dummy-5
            ticket: ticket2
            options:
              - name: loss-policy
                value: fence
    
      roles:
        - linux-system-roles.ha_cluster
  3. Save the file.
  4. Run the playbook, specifying the path to the inventory file inventory you created in Step 1.

    # ansible-playbook -i inventory new-cluster.yml

26.8. Configuring Corosync values in a high availability cluster

(RHEL 8.7 and later) The following procedure uses the ha_cluster System Role to create a high availability cluster that configures Corosync values.

Prerequisites

  • You have ansible-core installed on the node from which you want to run the playbook.

    Note

    You do not need to have ansible-core installed on the cluster member nodes.

  • You have the rhel-system-roles package installed on the system from which you want to run the playbook.
  • The systems that you will use as your cluster members have active subscription coverage for RHEL and the RHEL High Availability Add-On.
Warning

The ha_cluster System Role replaces any existing cluster configuration on the specified nodes. Any settings not specified in the role will be lost.

Procedure

  1. Create an inventory file specifying the nodes in the cluster, as described in Specifying an inventory for the ha_cluster System Role.
  2. Create a playbook file, for example new-cluster.yml.

    Note

    When creating your playbook file for production, Vault encrypt the password, as described in Encrypting content with Ansible Vault.

    The following example playbook file configures a cluster running the firewalld and selinux services that configures Corosync properties.

    - hosts: node1 node2
      vars:
        ha_cluster_cluster_name: my-new-cluster
        ha_cluster_hacluster_password: password
        ha_cluster_manage_firewall: true
        ha_cluster_manage_selinux: true
        ha_cluster_transport:
          type: knet
          options:
            - name: ip_version
              value: ipv4-6
            - name: link_mode
              value: active
          links:
            -
              - name: linknumber
                value: 1
              - name: link_priority
                value: 5
            -
              - name: linknumber
                value: 0
              - name: link_priority
                value: 10
          compression:
            - name: level
              value: 5
            - name: model
              value: zlib
          crypto:
            - name: cipher
              value: none
            - name: hash
              value: none
        ha_cluster_totem:
          options:
            - name: block_unlisted_ips
              value: 'yes'
            - name: send_join
              value: 0
        ha_cluster_quorum:
          options:
            - name: auto_tie_breaker
              value: 1
            - name: wait_for_all
              value: 1
    
      roles:
        - linux-system-roles.ha_cluster
  3. Save the file.
  4. Run the playbook, specifying the path to the inventory file inventory you created in Step 1.

    # ansible-playbook -i inventory new-cluster.yml

26.9. Configuring a high availability cluster with SBD node fencing

(RHEL 8.7 and later) The following procedure uses the ha_cluster System Role to create a high availability cluster that uses SBD node fencing.

Prerequisites

  • You have ansible-core installed on the node from which you want to run the playbook.

    Note

    You do not need to have ansible-core installed on the cluster member nodes.

  • You have the rhel-system-roles package installed on the system from which you want to run the playbook.
  • The systems that you will use as your cluster members have active subscription coverage for RHEL and the RHEL High Availability Add-On.
Warning

The ha_cluster System Role replaces any existing cluster configuration on the specified nodes. Any settings not specified in the role will be lost.

This playbook uses an inventory file that loads a watchdog module (supported in RHEL 8.9 and later) as described in Configuring watchdog and SBD devices in an inventory.

Procedure

  1. Create an inventory file specifying the nodes in the cluster that configures watchdog and SBD devices, as described in Configuring watchdog and SBD devices in an inventory.
  2. Create a playbook file, for example new-cluster.yml.

    Note

    When creating your playbook file for production, vault encrypt the password, as described in Encrypting content with Ansible Vault.

    The following example playbook file configures a cluster running the firewalld and selinux services that uses SBD fencing and creates the SBD Stonith resource. This playbook uses an inventory file that loads a watchdog module (supported in RHEL 8.9 and later) as described in Configuring watchdog and SBD devices in an inventory.

    - hosts: node1 node2
      vars:
        ha_cluster_cluster_name: my-new-cluster
        ha_cluster_hacluster_password: password
        ha_cluster_manage_firewall: true
        ha_cluster_manage_selinux: true
        ha_cluster_sbd_enabled: yes
        ha_cluster_sbd_options:
          - name: delay-start
            value: 'no'
          - name: startmode
            value: always
          - name: timeout-action
            value: 'flush,reboot'
          - name: watchdog-timeout
            value: 30
        # Suggested optimal values for SBD timeouts:
        # watchdog-timeout * 2 = msgwait-timeout (set automatically)
        # msgwait-timeout * 1.2 = stonith-timeout
        ha_cluster_cluster_properties:
          - attrs:
              - name: stonith-timeout
                value: 72
        ha_cluster_resource_primitives:
          - id: fence_sbd
            agent: 'stonith:fence_sbd'
            instance_attrs:
              - attrs:
                  # taken from host_vars
                  - name: devices
                    value: "{{ ha_cluster.sbd_devices | join(',') }}"
                  - name: pcmk_delay_base
                    value: 30
    
      roles:
        - linux-system-roles.ha_cluster
  3. Save the file.
  4. Run the playbook, specifying the path to the inventory file inventory you created in Step 1.

    # ansible-playbook -i inventory new-cluster.yml

26.10. Configuring a high availability cluster using a quorum device (RHEL 8.8 and later)

To configure a high availability cluster with a separate quorum device by using the ha_cluster System Role, first set up the quorum device. After setting up the quorum device, you can use the device in any number of clusters.

26.10.1. Configuring a quorum device

To configure a quorum device using the ha_cluster System Role, follow these steps. Note that you cannot run a quorum device on a cluster node.

Prerequisites

  • The ansible-core and the rhel-system-roles packages are installed on the node from which you want to run the playbook.

    Note

    You do not need to have ansible-core installed on the cluster member nodes.

  • The system that you will use to run the quorum device has active subscription coverage for RHEL and the RHEL High Availability Add-On.
Warning

The ha_cluster System Role replaces any existing cluster configuration on the specified nodes. Any settings not specified in the role will be lost.

Procedure

  1. Create a playbook file, for example qdev-playbook.yml.

    Note

    When creating your playbook file for production, vault encrypt the password, as described in Encrypting content with Ansible Vault.

    The following example playbook file configures a quorum device on a system running the firewalld and selinux services.

    - hosts: nodeQ
      vars:
        ha_cluster_cluster_present: false
        ha_cluster_hacluster_password: password
        ha_cluster_manage_firewall: true
        ha_cluster_manage_selinux: true
        ha_cluster_qnetd:
          present: true
    
      roles:
        - linux-system-roles.ha_cluster
  2. Save the file.
  3. Run the playbook, specifying the host node for the quorum device.

    # ansible-playbook -i nodeQ, qdev-playbook.yml

26.10.2. Configuring a cluster to use a quorum device

To configure a cluster to use a quorum device, follow these steps.

Prerequisites

  • You have ansible-core installed on the node from which you want to run the playbook.

    Note

    You do not need to have ansible-core installed on the cluster member nodes.

  • You have the rhel-system-roles package installed on the system from which you want to run the playbook.
  • The systems that you will use as your cluster members have active subscription coverage for RHEL and the RHEL High Availability Add-On.
  • You have configured a quorum device.
Warning

The ha_cluster System Role replaces any existing cluster configuration on the specified nodes. Any settings not specified in the role will be lost.

Procedure

  1. Create an inventory file specifying the nodes in the cluster, as described in Specifying an inventory for the ha_cluster System Role.
  2. Create a playbook file, for example new-cluster.yml.

    Note

    When creating your playbook file for production, vault encrypt the password, as described in Encrypting content with Ansible Vault.

    The following example playbook file configures a cluster running the firewalld and selinux services that uses a quorum device.

    - hosts: node1 node2
      vars:
        ha_cluster_cluster_name: my-new-cluster
        ha_cluster_hacluster_password: password
        ha_cluster_manage_firewall: true
        ha_cluster_manage_selinux: true
        ha_cluster_quorum:
          device:
            model: net
            model_options:
              - name: host
                value: nodeQ
              - name: algorithm
                value: lms
    
      roles:
        - linux-system-roles.ha_cluster
  3. Save the file.
  4. Run the playbook, specifying the path to the inventory file inventory you created in Step 1.

    # ansible-playbook -i inventory new-cluster.yml

26.11. Configuring an Apache HTTP server in a high availability cluster with the ha_cluster System Role

This procedure configures an active/passive Apache HTTP server in a two-node Red Hat Enterprise Linux High Availability Add-On cluster using the ha_cluster System Role.

Prerequisites

  • You have ansible-core installed on the node from which you want to run the playbook.

    Note

    You do not need to have ansible-core installed on the cluster member nodes.

  • You have the rhel-system-roles package installed on the system from which you want to run the playbook.
  • The systems that you will use as your cluster members have active subscription coverage for RHEL and the RHEL High Availability Add-On.
  • Your system includes a public virtual IP address, required for Apache.
  • Your system includes shared storage for the nodes in the cluster, using iSCSI, Fibre Channel, or other shared network block device.
  • You have configured an LVM logical volume with an XFS file system, as described in Configuring an LVM volume with an XFS file system in a Pacemaker cluster.
  • You have configured an Apache HTTP server, as described in Configuring an Apache HTTP Server.
  • Your system includes an APC power switch that will be used to fence the cluster nodes.
Warning

The ha_cluster System Role replaces any existing cluster configuration on the specified nodes. Any settings not specified in the role will be lost.

Procedure

  1. Create an inventory file specifying the nodes in the cluster, as described in Specifying an inventory for the ha_cluster System Role.
  2. Create a playbook file, for example http-cluster.yml.

    Note

    When creating your playbook file for production, vault encrypt the password, as described in Encrypting content with Ansible Vault.

    The following example playbook file configures a previously-created Apache HTTP server in an active/passive two-node HA cluster running the firewalld and selinux services.

    This example uses an APC power switch with a host name of zapc.example.com. If the cluster does not use any other fence agents, you can optionally list only the fence agents your cluster requires when defining the ha_cluster_fence_agent_packages variable, as in this example.

    - hosts: z1.example.com z2.example.com
      roles:
        - rhel-system-roles.ha_cluster
      vars:
        ha_cluster_hacluster_password: password
        ha_cluster_cluster_name: my_cluster
        ha_cluster_manage_firewall: true
        ha_cluster_manage_selinux: true
        ha_cluster_fence_agent_packages:
          - fence-agents-apc-snmp
        ha_cluster_resource_primitives:
          - id: myapc
            agent: stonith:fence_apc_snmp
            instance_attrs:
              - attrs:
                  - name: ipaddr
                    value: zapc.example.com
                  - name: pcmk_host_map
                    value: z1.example.com:1;z2.example.com:2
                  - name: login
                    value: apc
                  - name: passwd
                    value: apc
          - id: my_lvm
            agent: ocf:heartbeat:LVM-activate
            instance_attrs:
              - attrs:
                  - name: vgname
                    value: my_vg
                  - name: vg_access_mode
                    value: system_id
          - id: my_fs
            agent: Filesystem
            instance_attrs:
              - attrs:
                  - name: device
                    value: /dev/my_vg/my_lv
                  - name: directory
                    value: /var/www
                  - name: fstype
                    value: xfs
          - id: VirtualIP
            agent: IPaddr2
            instance_attrs:
              - attrs:
                  - name: ip
                    value: 198.51.100.3
                  - name: cidr_netmask
                    value: 24
          - id: Website
            agent: apache
            instance_attrs:
              - attrs:
                  - name: configfile
                    value: /etc/httpd/conf/httpd.conf
                  - name: statusurl
                    value: http://127.0.0.1/server-status
        ha_cluster_resource_groups:
          - id: apachegroup
            resource_ids:
              - my_lvm
              - my_fs
              - VirtualIP
              - Website
  3. Save the file.
  4. Run the playbook, specifying the path to the inventory file inventory you created in Step 1.

    # ansible-playbook -i inventory http-cluster.yml
  5. When you use the apache resource agent to manage Apache, it does not use systemd. Because of this, you must edit the logrotate script supplied with Apache so that it does not use systemctl to reload Apache.

    Remove the following line in the /etc/logrotate.d/httpd file on each node in the cluster.

    /bin/systemctl reload httpd.service > /dev/null 2>/dev/null || true
    • For RHEL 8.6 and later, replace the line you removed with the following three lines, specifying /var/run/httpd-website.pid as the PID file path where website is the name of the Apache resource. In this example, the Apache resource name is Website.

      /usr/bin/test -f /var/run/httpd-Website.pid >/dev/null 2>/dev/null &&
      /usr/bin/ps -q $(/usr/bin/cat /var/run/httpd-Website.pid) >/dev/null 2>/dev/null &&
      /usr/sbin/httpd -f /etc/httpd/conf/httpd.conf -c "PidFile /var/run/httpd-Website.pid" -k graceful > /dev/null 2>/dev/null || true
    • For RHEL 8.5 and earlier, replace the line you removed with the following three lines.

      /usr/bin/test -f /run/httpd.pid >/dev/null 2>/dev/null &&
      /usr/bin/ps -q $(/usr/bin/cat /run/httpd.pid) >/dev/null 2>/dev/null &&
      /usr/sbin/httpd -f /etc/httpd/conf/httpd.conf -c "PidFile /run/httpd.pid" -k graceful > /dev/null 2>/dev/null || true

Verification steps

  1. From one of the nodes in the cluster, check the status of the cluster. Note that all four resources are running on the same node, z1.example.com.

    If you find that the resources you configured are not running, you can run the pcs resource debug-start resource command to test the resource configuration.

    [root@z1 ~]# pcs status
    Cluster name: my_cluster
    Last updated: Wed Jul 31 16:38:51 2013
    Last change: Wed Jul 31 16:42:14 2013 via crm_attribute on z1.example.com
    Stack: corosync
    Current DC: z2.example.com (2) - partition with quorum
    Version: 1.1.10-5.el7-9abe687
    2 Nodes configured
    6 Resources configured
    
    Online: [ z1.example.com z2.example.com ]
    
    Full list of resources:
     myapc  (stonith:fence_apc_snmp):       Started z1.example.com
     Resource Group: apachegroup
         my_lvm     (ocf::heartbeat:LVM-activate):   Started z1.example.com
         my_fs      (ocf::heartbeat:Filesystem):    Started z1.example.com
         VirtualIP  (ocf::heartbeat:IPaddr2):       Started z1.example.com
         Website    (ocf::heartbeat:apache):        Started z1.example.com
  2. Once the cluster is up and running, you can point a browser to the IP address you defined as the IPaddr2 resource to view the sample display, consisting of the simple word "Hello".

    Hello
  3. To test whether the resource group running on z1.example.com fails over to node z2.example.com, put node z1.example.com in standby mode, after which the node will no longer be able to host resources.

    [root@z1 ~]# pcs node standby z1.example.com
  4. After putting node z1 in standby mode, check the cluster status from one of the nodes in the cluster. Note that the resources should now all be running on z2.

    [root@z1 ~]# pcs status
    Cluster name: my_cluster
    Last updated: Wed Jul 31 17:16:17 2013
    Last change: Wed Jul 31 17:18:34 2013 via crm_attribute on z1.example.com
    Stack: corosync
    Current DC: z2.example.com (2) - partition with quorum
    Version: 1.1.10-5.el7-9abe687
    2 Nodes configured
    6 Resources configured
    
    Node z1.example.com (1): standby
    Online: [ z2.example.com ]
    
    Full list of resources:
    
     myapc  (stonith:fence_apc_snmp):       Started z1.example.com
     Resource Group: apachegroup
         my_lvm     (ocf::heartbeat:LVM-activate):   Started z2.example.com
         my_fs      (ocf::heartbeat:Filesystem):    Started z2.example.com
         VirtualIP  (ocf::heartbeat:IPaddr2):       Started z2.example.com
         Website    (ocf::heartbeat:apache):        Started z2.example.com

    The web site at the defined IP address should still display, without interruption.

  5. To remove z1 from standby mode, enter the following command.

    [root@z1 ~]# pcs node unstandby z1.example.com
    Note

    Removing a node from standby mode does not in itself cause the resources to fail back over to that node. This will depend on the resource-stickiness value for the resources. For information about the resource-stickiness meta attribute, see Configuring a resource to prefer its current node.

26.12. Additional resources

Chapter 27. Installing and configuring web console with the cockpit RHEL System Role

With the cockpit RHEL System Role, you can install and configure the web console in your system.

27.1. The cockpit System Role

You can use the cockpit System Role to automatically deploy and enable the web console and thus be able to manage your RHEL systems from a web browser.

27.2. Variables for the cockpit RHEL System Role

The parameters used for the cockpit RHEL System Roles are:

Role VariableDescription

cockpit_packages: (default: default)

Sets one of the predefined package sets: default, minimal, or full.

* cockpit_packages: (default: default) - most common pages and on-demand install UI

* cockpit_packages: (default: minimal) - just the Overview, Terminal, Logs, Accounts, and Metrics pages; minimal dependencies

* cockpit_packages: (default: full) - all available pages

Optionally, specify your own selection of cockpit packages you want to install.

cockpit_enabled: (default:true)

Configures if the web console web server is enabled to start automatically at boot

cockpit_started: (default:true)

Configures if the web console should be started

cockpit_config: (default: nothing)

You can apply settings in the /etc/cockpit/cockpit.conf file. NOTE: The previous settings file will be lost.

cockpit_port: (default: 9090)

The web console runs on port 9090 by default. You can change the port using this option.

cockpit_manage_firewall: (default: false)

Allows the cockpit role to control the firewall role to add ports. It cannot be used for removing ports. If you want to remove ports, you will need to use the firewall system role directly.

cockpit_manage_selinux: (default: false)

Allows the cockpit role to configure SELinux using the selinux role. The default SELinux policy does not allow Cockpit to listen on anything other than port 9090. If you change the port, set this option to true so that the selinux role can set the correct port permissions (websm_port_t).

cockpit_certificates: (default: nothing)

Allows the cockpit role to generate new certificates using the certificate role. The value of cockpit_certificates is passed on to the certificate_requests variable of the certificate role. This role is called internally by the cockpit role and it generates the private key and certificate.

Additional resources

27.3. Installing the web console by using the cockpit RHEL System Role

You can use the cockpit System Role to install and enable the RHEL web console.

By default, the RHEL web console uses a self-signed certificate. For security reasons, you can specify a certificate that was issued by a trusted certificate authority instead.

In this example, you use the cockpit System Role to:

  • Install the RHEL web console.
  • Allow the web console to manage firewalld.
  • Set the web console to use a certificate from the ipa trusted certificate authority instead of using a self-signed certificate.
  • Set the web console to use a custom port 9050.
Note

You do not have to call the firewall or certificate System Roles in the playbook to manage the Firewall or create the certificate. The cockpit System Role calls them automatically as needed.

Prerequisites

  • Access and permissions to one or more managed nodes.
  • Access and permissions to a control node.

    On the control node:

    • Red Hat Ansible Engine is installed.
    • The rhel-system-roles package is installed.
    • An inventory file exists that lists the managed nodes.

Procedure

  1. Create a new playbook.yml file with the following content:

    ---
    - hosts: all
      tasks:
        - name: Install RHEL web console
          include_role:
            name: rhel-system-roles.cockpit
          vars:
            cockpit_packages: default
            #cockpit_packages: minimal
            #cockpit_packages: full
            cockpit_port:9050
            cockpit_manage_selinux: true
            cockpit_manage_firewall: true
            cockpit_certificates:
              - name: /etc/cockpit/ws-certs.d/01-certificate
                dns: ['localhost', 'www.example.com']
                ca: ipa
                group: cockpit-ws
  2. Optional: Verify the playbook syntax:

    # ansible-playbook --syntax-check -i inventory_file playbook.yml
  3. Run the playbook on your inventory file:

    # ansible-playbook -i inventory_file /path/to/file/playbook.yml

Chapter 28. Managing containers by using the podman RHEL System Role

With the podman RHEL System Role, you can manage Podman configuration, containers, and systemd services that run Podman containers.

28.1. The podman RHEL System Role

You can use the podman RHEL System Role to manage Podman configuration, containers, and systemd services which run Podman containers.

Additional resources

  • For details about the parameters used in podman and additional information about the podman RHEL System Role, see the /usr/share/ansible/roles/rhel-system-roles.podman/README.md file.

28.2. Variables for the podman RHEL System Role

The parameters used for the podman RHEL System Role are the following:

VariableDescription

podman_kube_specs

Describes a Podman pod and the corresponding systemd unit.

  • state: (default: created) - denotes an operation to be executed with systemd services and pods:

    • created: create the pods and systemd service, but do not run them
    • started: create the pods and systemd services, and start them
    • absent: remove the pods and systemd services
  • run_as_user: (default: podman_run_as_user) - a per-pod user. If you do not specify a user, it uses root.

    Note

    The user must already exist.

  • run_as_group (default: podman_run_as_group) - a per-pod group. If you do not specify a user, it uses root.

    Note

    The group must already exist.

  • systemd_unit_scope (default: podman_systemd_unit_scope) - scope to use for the systemd unit. If you do not not specify, it uses system is for root containers, and user for user containers.
  • kube_file_src - name of a Kubernetes YAML file on the controller node which will be copied to kube_file on the managed node

    Note

    Do not specify the kube_file_src variable if you specify the kube_file_content variable. The kube_file_content takes precedence over kube_file_src.

  • kube_file_content - string in Kubernetes YAML format or a dict in Kubernetes YAML format. It specifies the contents of kube_file on the managed node.

    Note

    Do not specify the kube_file_content variable if you specify kube_file_src variable. The kube_file_content takes precedence over kube_file_src.

  • kube_file - a file name on the managed node that contains the Kubernetes specification of the container or pod. You typically do not have to specify the kube_file variable unless you need to copy the kube_file file to the managed node outside of the role. If you specify either kube_file_src or kube_file_content, you do not have to specify this.

    Note

    It is highly recommended to omit kube_file and instead specify either kube_file_src or kube_file_content and let the role manage the file path and name.

    • The file basename will be the metadata.name value from the K8s yaml, with a .yml suffix appended to it.
    • The directory is /etc/containers/ansible-kubernetes.d for system services.
    • The directory is $HOME/.config/containers/ansible-kubernetes.d for user services.
    • This will be copied to the file /etc/containers/ansible-kubernetes.d/<application_name>.yml on the managed node.

podman_quadlet_specs

List of Quadlet specifications.

Warning

Quadlets work only with rootful containers on RHEL 8. Quadlets work with rootless containers only on RHEL 9.

Quadlet is defined by a name and type of a unit. Types of a unit can be the following: container, kube, network, volume. You can either pass in name and type explicitly, or the name and type will be derived from the file name given in file, file_src, or template_src.

  • The root containers files are in /etc/containers/systemd/$name.$type on the managed node.
  • The rootless containers files are in $HOME/.config/containers/systemd/$name.$type on the managed node.

When a Quadlet specification depends on some other file, for example quadlet.kube that depends on the Yaml file or a ConfigMap, then that file must be specified in the podman_quadlet_specs list before the file that uses it. For example, if you have a my-app.kube file:

[Kube]
ConfigMap=my-app-config.yml
Yaml=my-app.yml
...

Then you must specify my-app-config.yml and my-app.yml before my-app.kube:

podman_quadlet_specs:
  - file_src: my-app-config.yml
  - file_src: my-app.yml
  - file_src: my-app.kube

Most of the parameters for each Quadlet specification are the same as for podman_kube_spec above, except that the kube parameters are not supported. The following parameters are supported:

  • name - name of the unit. If you do not specify a name, it is derived from file, file_src, or template_src.

    • For example, if you specify file_src: /path/to/my-container.container then the name is my-container.
  • type - type of a unit can be the following: container, kube, network, volume. If you do not specify a name, it is derived from file, file_src, or template_src.

    • For example, if you specify file_src: /path/to/my-container.container then the type is container.

      Note

      If this file is in the Quadlet unit format and has a valid Quadlet unit suffix, it is used as a Quadlet unit, otherwise, it is just copied.

  • file_src - name of the file on the control node to copy to the managed node to use as the source of the Quadlet unit.

    Note

    If this file is in the Quadlet unit format and has a valid Quadlet unit suffix, it is used as a Quadlet unit, otherwise, it is just copied.

  • file - name of the file on the managed node to use as the source of the Quadlet unit.

    Note

    If this file is in the Quadlet unit format and has a valid Quadlet unit suffix, it is used as a Quadlet unit, otherwise, it is just copied.

  • file_content - the contents of a file to copy to the managed node, in string format. This is useful to pass in short files that can easily be specified inline. You must specify name and type.
  • template_src - the name of the file on the control node which will be processed as a Jinja * template file, then copied to the managed node to use as the source of the Quadlet unit.

    Note

    If this file is in the Quadlet unit format and has a valid Quadlet unit suffix, it is used as a Quadlet unit, otherwise, it is just copied. If the file has a .j2 suffix, that suffix will be removed to determine the quadlet file type.

    • For example, if you specify:

      podman_quadlet_specs:
        - template_src: my-app.container.j2

      Then the local file templates/my-app.container.j2 will be processed as a Jinja template file, then copied to /etc/containers/systemd/my-app.container as a Quadlet container unit specification on the managed node.

podman_secrets

List of secret specs in the same format as used by podman_secret, except that there is an additional field run_as_user used to create the secret in the account of a specified user. If this is not specified, then the secret will be created in the account specified by podman_run_as_user, and the default value of that is "root" Use Ansible Vault to encrypt the value of the data field.

podman_create_host_directories

If true, the role ensures host directories specified in host mounts in volumes.hostPath specifications in the Kubernetes YAML given in podman_kube_specs. The default value is false.

Note

To ensure that the role manages the directories, you must specify directories as absolute paths for root containers, or paths relative to the home directory, for non-root containers.

The role applies its default ownership or permissions to the directories. If you need to set ownership or permissions, see podman_host_directories.

podman_host_directories

It is a dict. If using podman_create_host_directories to tell the role to create host directories for volume mounts, and you need to specify permissions or ownership that apply to these created host directories, use podman_host_directories. Each key is the absolute path of the host directory to manage. The value is in the format of the parameters to the file module. If you do not specify a value, the role will use its built-in default values. If you want to specify a value to be used for all host directories, use the special key DEFAULT.

podman_firewall

It is a list of dict. Specifies ports that you want the role to manage in the firewall. This uses the same format as used by the firewall RHEL System Role.

podman_selinux_ports

It is a list of dict. Specifies ports that you want the role to manage the SELinux policy for ports used by the role. This uses the same format as used by the selinux RHEL System Role.

podman_run_as_user

Specifies the name of the user to use for all rootless containers. You can also specify per-container/unit/secret username with run_as_user in podman_kube_specs, podman_quadlet_specs, or podman_secrets. .

Note

The user must already exist.

podman_run_as_group

Specifies the name of the group to use for all rootless containers. You can also specify a per-container or unit group name with run_as_group in podman_kube_specs or podman_quadlet_specs.

Note

The group must already exist.

podman_systemd_unit_scope

Defines the systemd scope to use by default for all systemd units. You can also specify per-container or unit scope with systemd_unit_scope in podman_kube_specs and podman_quadlet_specs. By default, rootless containers use user and root containers use system.

podman_containers_conf

Defines the containers.conf(5) settings as a dict. The setting is provided in a drop-in file in the containers.conf.d directory. If running as root, the system settings are managed. See podman_run_as_user.Otherwise, the user settings are managed. See the containers.conf man page for the directory locations.

podman_registries_conf

Defines the containers-registries.conf(5) settings as a dict. The setting is provided in a drop-in file in the registries.conf.d directory. If running as root, the system settings are managed. See podman_run_as_user. Otherwise, the user settings are managed. See the registries.conf man page for the directory locations.

podman_storage_conf

Defines the containers-storage.conf(5) settings as a dict. If running as root, the system settings are managed. See podman_run_as_user. Otherwise, the user settings are managed. See the storage.conf man page for the directory locations.

podman_policy_json

Defines the containers-policy.conf(5) settings as a dict. If running as root (see podman_run_as_user), the system settings are managed. Otherwise, the user settings are managed. See the policy.json man page for the directory locations.

Additional resources

  • For details about the parameters used in podman and additional information about the podman RHEL System Role, see the /usr/share/ansible/roles/rhel-system-roles.podman/README.md file.

28.3. Additional resources

  • For details about the parameters used in podman and additional information about the podman RHEL System Role, see the /usr/share/ansible/roles/rhel-system-roles.podman/README.md file.
  • For details about the ansible-playbook command, see the ansible-playbook(1) man page.

Chapter 29. Integrating RHEL systems into AD directly with Ansible using RHEL System Roles

With the ad_integration System Role, you can automate a direct integration of a RHEL system with Active Directory (AD) using Red Hat Ansible Automation Platform.

This chapter covers the following topics:

29.1. The ad_integration System Role

Using the ad_integration System Role, you can directly connect a RHEL system to Active Directory (AD).

The role uses the following components:

  • SSSD to interact with the central identity and authentication source
  • realmd to detect available AD domains and configure the underlying RHEL system services, in this case SSSD, to connect to the selected AD domain
Note

The ad_integration role is for deployments using direct AD integration without an Identity Management (IdM) environment. For IdM environments, use the ansible-freeipa roles.

29.2. Variables for the ad_integration RHEL System Role

The ad_integration RHEL System Role uses the following parameters:

Role VariableDescription

ad_integration_realm

Active Directory realm, or domain name to join.

ad_integration_password

The password of the user used to authenticate with when joining the machine to the realm. Do not use plain text. Instead, use Ansible Vault to encrypt the value.

ad_integration_manage_crypto_policies

If true, the ad_integration role will use fedora.linux_system_roles.crypto_policies as needed.

Default: false

ad_integration_allow_rc4_crypto

If true, the ad_integration role will set the crypto policy to allow RC4 encryption.

Providing this variable automatically sets ad_integration_manage_crypto_policies to true.

Default: false

ad_integration_timesync_source

Hostname or IP address of time source to synchronize the system clock with. Providing this variable automatically sets ad_integration_manage_timesync to true.

Additional resources

  • The /usr/share/ansible/roles/rhel-system-roles.ad_integration/README.md file.

29.3. Connecting a RHEL system directly to AD using the ad_integration System Role

You can use the ad_integration System Role to configure a direct integration between a RHEL system and an AD domain by running an Ansible playbook.

Note

Starting with RHEL8, RHEL no longer supports RC4 encryption by default. If it is not possible to enable AES in the AD domain, you must enable the AD-SUPPORT crypto policy and allow RC4 encryption in the playbook.

Important

Time between the RHEL server and AD must be synchronized. You can ensure this by using the timesync System Role in the playbook.

In this example, the RHEL system joins the domain.example.com AD domain, using the AD Administrator user and the password for this user stored in the Ansible vault. The playbook also sets the AD-SUPPORT crypto policy and allows RC4 encryption. To ensure time synchronization between the RHEL system and AD, the playbook sets the adserver.domain.example.com server as the timesync source.

Prerequisites

  • Access and permissions to one or more managed nodes.
  • Access and permissions to a control node.

    On the control node:

    • Red Hat Ansible Engine is installed.
    • The rhel-system-roles package is installed.
    • An inventory file which lists the managed nodes.
  • The following ports on the AD domain controllers are open and accessible from the RHEL server:

    Table 29.1. Ports Required for Direct Integration of Linux Systems into AD Using the ad_integration System Role

    Source PortDestination PortProtocolService

    1024:65535

    53

    UDP and TCP

    DNS

    1024:65535

    389

    UDP and TCP

    LDAP

    1024:65535

    636

    TCP

    LDAPS

    1024:65535

    88

    UDP and TCP

    Kerberos

    1024:65535

    464

    UDP and TCP

    Kerberos change/set password (kadmin)

    1024:65535

    3268

    TCP

    LDAP Global Catalog

    1024:65535

    3269

    TCP

    LDAP Global Catalog SSL/TLS

    1024:65535

    123

    UDP

    NTP/Chrony (Optional)

    1024:65535

    323

    UDP

    NTP/Chrony (Optional)

Procedure

  1. Create a new ad_integration.yml file with the following content:

    ---
    - hosts: all
      vars:
        ad_integration_realm: "domain.example.com"
        ad_integration_password: !vault | vault encrypted password
        ad_integration_manage_crypto_policies: true
        ad_integration_allow_rc4_crypto: true
        ad_integration_timesync_source: "adserver.domain.example.com"
      roles:
        - linux-system-roles.ad_integration
    ---
  2. Optional: Verify playbook syntax.

    # ansible-playbook --syntax-check ad_integration.yml -i inventory_file
  3. Run the playbook on your inventory file:

    # ansible-playbook -i inventory_file /path/to/file/ad_integration.yml

Verification

  • Display an AD user details, such as the administrator user:

    getent passwd administrator@ad.example.com
    administrator@ad.example.com:*:1450400500:1450400513:Administrator:/home/administrator@ad.example.com:/bin/bash

29.4. Additional resources

  • The /usr/share/ansible/roles/rhel-system-roles.ad_integration/README.md file.
  • man ansible-playbook(1)

Chapter 30. Installing and configuring PostgreSQL by using the postgresql RHEL System Role

As a system administrator, you can use the postgresql RHEL System Role to install, configure, manage, start, and improve performance of the PostgreSQL server.

30.1. Introduction to the postgresql RHEL System Role

To install, configure, manage, and start the PostgreSQL server using Ansible, you can use the postgresql RHEL System Role.

You can also use the postgresql role to optimize the database server settings and improve performance.

The role supports the currently released and supported versions of PostgreSQL on RHEL 8 and RHEL 9 managed nodes.

Additional resources

30.2. Configuring the PostgreSQL server by using RHEL System Roles

You can use the postgresql RHEL System Role to install, configure, manage, and start the PostgreSQL server.

Warning

The postgresql role replaces PostgreSQL configuration files in the /var/lib/pgsql/data/ directory on the managed hosts. Previous settings are changed to those specified in the role variables, and lost if they are not specified in the role variables.

Prerequisites

Procedure

  1. Create a new postgresql-playbook.yml file with the following content:

    - name: Manage postgres
      hosts: all
      vars:
        postgresql_version: "13"
      roles:
        - rhel-system-roles.postgresql
  2. Optional: Verify playbook syntax.

    # ansible-playbook --syntax-check postgresql-playbook.yml
  3. Run the playbook on your inventory file:

    # ansible-playbook -i inventory_file /path/to/file/postgresql-playbook.yml

Additional resources

30.3. The postgresql role variables

You can use the following variables of the postgresql RHEL System Role to customize the PostgreSQL server behavior.

postgresql_verison

You can set the version of the PostgreSQL server to 10, 12, or 13. For example:

postgresql_version: "13"
postgresql_password

Optionally, you can set a password for the postgres database superuser. By default, no password is set, and a database is accessible from the postgres system account through a UNIX socket. It is recommended to encrypt the password by using Ansible Vault. For example:

postgresql_password: !vault |
      	$ANSIBLE_VAULT;1.2;AES256;dev
      	....
postgresql_pg_hba_conf

The content of the postgresql_pg_hba_conf variable replaces the default upstream configuration in the /var/lib/pgsql/data/pg_hba.conf file. For example:

postgresql_pg_hba_conf:
  - type: local
    database: all
    user: all
    auth_method: peer
  - type: host
    database: all
    user: all
    address: '127.0.0.1/32'
    auth_method: ident
  - type: host
    database: all
    user: all
    address: '::1/128'
    auth_method: ident
postgresql_server_conf

The content of the postgresql_server_conf variable is added to the end of the /var/lib/pgsql/data/postgresql.conf file. As a result, the default settings are overwritten. For example:

postgresql_server_conf:
  ssl: on
  shared_buffers: 128MB
  huge_pages: try
postgresql_ssl_enable

To set up an SSL/TLS connection, set the postgresql_ssl_enable variable to true:

postgresql_ssl_enable: true

and use one of the following approaches to provide a server certificate and a private key:

  • Use the postgresql_cert_name variable if you want to use an existing certificate and private key.
  • Use the postgresql_certificates variable to generate a new certificate.
postgresql_cert_name

If you want to use your own certificate and private key, use the postgresql_cert_name variable to specify the certificate name. You must keep both certificate and key files in the same directory and under the same name with the .crt and .key suffixes.

For example, if your certificate file is located in /etc/certs/server.crt and your private key in /etc/certs/server.key, set the postgresql_cert_name value to:

postgresql_cert_name: /etc/certs/server
postgresql_certificates

The postgresql_certificates variable requires a list of dict in the same format as used by the redhat.rhel_system_roles.certificate role. Specify the postgresql_certificates variable if you want the certificate role to generate certificates for the PostgreSQL server configured by the PostgreSQL role. In the following example, a self-signed certificate postgresql_cert.crt is generated in the /etc/pki/tls/certs/ directory. By default, no certificates are automatically generated ([]).

postgresql_certificates:
  - name: postgresql_cert
    dns: ['localhost', 'www.example.com']
    ca: self-sign
postgresql_input_file

To run an SQL script, define a path to your SQL file by using the postgresql_input_file variable:

postgresql_input_file: "/tmp/mypath/file.sql"
postgresql_server_tuning

By default, the PostgreSQL system role enables server settings optimization based on system resources. To disable the tuning, set the postgresql_server_tuning variable to false:

postgresql_server_tuning: false

Additional resources

  • Documentation installed with the rhel-system-roles package: the README.md or README.html files in the /usr/share/doc/rhel-system-roles/postgresql/ directory

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