Automating system administration by using RHEL system roles

Red Hat Enterprise Linux 9

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.

Making open source more inclusive

Red Hat is committed to replacing problematic language in our code, documentation, and web properties. We are beginning with these four terms: master, slave, blacklist, and whitelist. Because of the enormity of this endeavor, these changes will be implemented gradually over several upcoming releases. For more details, see our CTO Chris Wright’s message.

Providing feedback on Red Hat documentation

We appreciate your feedback on our documentation. Let us know how we can improve it.

Submitting feedback through Jira (account required)

  1. Log in to the Jira website.
  2. Click Create in the top navigation bar
  3. Enter a descriptive title in the Summary field.
  4. Enter your suggestion for improvement in the Description field. Include links to the relevant parts of the documentation.
  5. Click Create at the bottom of the dialogue.

Chapter 1. Introduction to RHEL system roles

By using RHEL system roles, you can remotely manage the system configurations of multiple RHEL systems across major versions of RHEL.

Important terms and concepts

The following describes important terms and concepts in an Ansible environment:

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 9.
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.

Available roles on a Red Hat Enterprise Linux 9 control node

On a Red Hat Enterprise Linux 9 control node, the rhel-system-roles package provides the following roles:

Role nameRole descriptionChapter title

certificate

Certificate Issuance and Renewal

Requesting certificates by 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 by using system roles

kdump

Kernel Dumps

Configuring kdump by 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 by using RHEL system roles

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 by 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 by using RHEL system roles

tlog

Terminal Session Recording

Configuring a system for session recording by using the tlog RHEL system role

timesync

Time Synchronization

Configuring time synchronization by 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 9

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

  • The system is registered to the Customer Portal.
  • A Red Hat Enterprise Linux Server subscription is attached to the system.
  • Optional: An Ansible Automation Platform subscription is attached to the system.

Procedure

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

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

    [root@control-node]# su - ansible

    Perform the rest of the procedure as this user.

  3. 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.

  4. Optional: To prevent Ansible from prompting you for the SSH key password each time you establish a connection, configure an SSH agent.
  5. 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.
  6. 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.

  7. Install RHEL system roles:

    • On a RHEL host without Ansible Automation Platform, install the rhel-system-roles package:

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

      This command installs the collections in the /usr/share/ansible/collections/ansible_collections/redhat/rhel_system_roles/ directory, and the ansible-core package as a dependency.

    • On Ansible Automation Platform, perform the following steps as the ansible user:

      1. Define Red Hat automation hub as the primary source for content in the ~/.ansible.cfg file.
      2. Install the redhat.rhel_system_roles collection from Red Hat automation hub:

        [ansible@control-node]$ ansible-galaxy collection install redhat.rhel_system_roles

        This command installs the collection in the ~/.ansible/collections/ansible_collections/redhat/rhel_system_roles/ directory.

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 9.
  • 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) manual 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. Ansible vault

Sometimes your playbook needs to use sensitive data such as passwords, API keys, and other secrets to configure managed hosts. Storing this information in plain text in variables or other Ansible-compatible files is a security risk because any user with access to those files can read the sensitive data.

With Ansible vault, you can encrypt, decrypt, view, and edit sensitive information. They could be included as:

  • Inserted variable files in an Ansible Playbook
  • Host and group variables
  • Variable files passed as arguments when executing the playbook
  • Variables defined in Ansible roles

You can use Ansible vault to securely manage individual variables, entire files, or even structured data like YAML files. This data can then be safely stored in a version control system or shared with team members without exposing sensitive information.

Important

Files are protected with symmetric encryption of the Advanced Encryption Standard (AES256), where a single password or passphrase is used both to encrypt and decrypt the data. Note that the way this is done has not been formally audited by a third party.

To simplify management, it makes sense to set up your Ansible project so that sensitive variables and all other variables are kept in separate files, or directories. Then you can protect the files containing sensitive variables with the ansible-vault command.

Creating an encrypted file

The following command prompts you for a new vault password. Then it opens a file for storing sensitive variables using the default editor.

# ansible-vault create vault.yml
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>

Viewing an encrypted file

The following command prompts you for your existing vault password. Then it displays the sensitive contents of an already encrypted file.

# ansible-vault view vault.yml
Vault password: <vault_password>
my_secret: "yJJvPqhsiusmmPPZdnjndkdnYNDjdj782meUZcw"

Editing an encrypted file

The following command prompts you for your existing vault password. Then it opens the already encrypted file for you to update the sensitive variables using the default editor.

# ansible-vault edit vault.yml
Vault password: <vault_password>

Encrypting an existing file

The following command prompts you for a new vault password. Then it encrypts an existing unencrypted file.

# ansible-vault encrypt vault.yml
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
Encryption successful

Decrypting an existing file

The following command prompts you for your existing vault password. Then it decrypts an existing encrypted file.

# ansible-vault decrypt vault.yml
Vault password: <vault_password>
Decryption successful

Changing the password of an encrypted file

The following command prompts you for your original vault password, then for the new vault password.

# ansible-vault rekey vault.yml
Vault password: <vault_password>
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
Rekey successful

Basic application of Ansible vault variables in a playbook

---
- name: Create user accounts for all servers
  hosts: managed-node-01.example.com
  vars_files:
    - vault.yml
  tasks:
    - name: Create user from vault.yml file
      user:
        name: "{{ username }}"
        password: "{{ pwhash }}"

You read-in the file with variables (vault.yml) in the vars_files section of your Ansible Playbook, and you use the curly brackets the same way you would do with your ordinary variables. Then you either run the playbook with the ansible-playbook --ask-vault-pass command and you enter the password manually. Or you save the password in a separate file and you run the playbook with the ansible-playbook --vault-password-file /path/to/my/vault-password-file command.

Additional resources

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. 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

  • 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 ansible-collection-redhat-rhel_mgmt package is installed.
  • The python3-pyghmi package is installed either on the control node or the managed nodes.
  • The IPMI BMC that you want to control is accessible over network from the control node 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 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 playbook file, for example ~/playbook.yml, with the following content:

    ---
    - name: Set boot device to be used on next boot
      hosts: managed-node-01.example.com
      tasks:
        - name: Ensure boot device is HD
          redhat.rhel_mgmt.ipmi_boot:
            user: <admin_user>
            password: <password>
            bootdev: hd
  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Verification

  • When you run the playbook, Ansible returns success.

Additional resources

  • /usr/share/ansible/collections/ansible_collections/redhat/rhel_mgmt/README.md file

4.3. 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

  • 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 ansible-collection-redhat-rhel_mgmt package is installed.
  • The python3-pyghmi package is installed either on the control node or the managed nodes.
  • The IPMI BMC that you want to control is accessible over network from the control node 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 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 playbook file, for example ~/playbook.yml, with the following content:

    ---
    - name: Power management
      hosts: managed-node-01.example.com
      tasks:
        - name: Ensure machine is powered on
          redhat.rhel_mgmt.ipmi_power:
            user: <admin_user>
            password: <password>
            state: on
  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Verification

  • When you run the playbook, Ansible returns true.

Additional resources

  • /usr/share/ansible/collections/ansible_collections/redhat/rhel_mgmt/README.md file

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

  • 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 ansible-collection-redhat-rhel_mgmt package is installed.
  • The python3-pyghmi package is installed either on the control node or the managed nodes.
  • OOB controller access details.

Procedure

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

    ---
    - name: Manage out-of-band controllers using Redfish APIs
      hosts: managed-node-01.example.com
      tasks:
        - name: Get CPU inventory
          redhat.rhel_mgmt.redfish_info:
            baseuri: "<URI>"
            username: "<username>"
            password: "<password>"
            category: Systems
            command: GetCpuInventory
          register: result
  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Verification

  • When you run the playbook, Ansible returns the CPU inventory details.

Additional resources

  • /usr/share/ansible/collections/ansible_collections/redhat/rhel_mgmt/README.md file

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

  • 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 ansible-collection-redhat-rhel_mgmt package is installed.
  • The python3-pyghmi package is installed either on the control node or the managed nodes.
  • OOB controller access details.

Procedure

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

    ---
    - name: Manage out-of-band controllers using Redfish APIs
      hosts: managed-node-01.example.com
      tasks:
        - name: Power on system
          redhat.rhel_mgmt.redfish_command:
            baseuri: "<URI>"
            username: "<username>"
            password: "<password>"
            category: Systems
            command: PowerOn
  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Verification

  • The system powers on.

Additional resources

  • /usr/share/ansible/collections/ansible_collections/redhat/rhel_mgmt/README.md file

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

  • 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 ansible-collection-redhat-rhel_mgmt package is installed.
  • The python3-pyghmi package is installed either on the control node or the managed nodes.
  • OOB controller access details.

Procedure

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

    ---
    - name: Manages out-of-band controllers using Redfish APIs
      hosts: managed-node-01.example.com
      tasks:
        - name: Set BootMode to UEFI
          redhat.rhel_mgmt.redfish_config:
            baseuri: "<URI>"
            username: "<username>"
            password: "<password>"
    	category: Systems
            command: SetBiosAttributes
            bios_attributes:
              BootMode: Uefi
  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Verification

  • The system boot mode is set to UEFI.

Additional resources

  • /usr/share/ansible/collections/ansible_collections/redhat/rhel_mgmt/README.md file

Chapter 6. Integrating RHEL systems into AD directly by using the RHEL system role

With the ad_integration system role, you can automate a direct integration of a RHEL system with Active Directory (AD) by using Red Hat Ansible Automation Platform.

6.1. The ad_integration RHEL 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.

Additional resources

Chapter 7. Requesting certificates by using the RHEL system role

You can use the certificate system role to issue and manage certificates.

7.1. The certificate RHEL 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

  • /usr/share/ansible/roles/rhel-system-roles.certificate/README.md file
  • /usr/share/doc/rhel-system-roles/certificate/ directory

7.2. Requesting a new self-signed certificate by using the certificate RHEL 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.

Prerequisites

Procedure

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

    ---
    - hosts: managed-node-01.example.com
      roles:
        - rhel-system-roles.certificate
      vars:
        certificate_requests:
          - name: mycert
            dns: "*.example.com"
            ca: self-sign
    • 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.

    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.

  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.certificate/README.md file
  • /usr/share/doc/rhel-system-roles/certificate/ directory

7.3. Requesting a new certificate from IdM CA by using the certificate RHEL 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.

Prerequisites

Procedure

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

    ---
    - hosts: managed-node-01.example.com
      roles:
        - rhel-system-roles.certificate
      vars:
        certificate_requests:
          - name: mycert
            dns: www.example.com
            principal: HTTP/www.example.com@EXAMPLE.COM
            ca: ipa
    • 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.

    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.

  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.certificate/README.md file
  • /usr/share/doc/rhel-system-roles/certificate/ directory

7.4. Specifying commands to run before or after certificate issuance by using the certificate RHEL 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.

Prerequisites

Procedure

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

    ---
    - hosts: managed-node-01.example.com
      roles:
        - rhel-system-roles.certificate
      vars:
        certificate_requests:
          - name: mycert
            dns: www.example.com
            ca: self-sign
            run_before: systemctl stop httpd.service
            run_after: systemctl start httpd.service
    • 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.

    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.

  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.certificate/README.md file
  • /usr/share/doc/rhel-system-roles/certificate/ directory

Chapter 8. Installing and configuring web console by using the RHEL system role

With the cockpit RHEL system role, you can install and configure the web console in your system.

8.1. The cockpit RHEL 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.

8.2. 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

Procedure

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

    ---
    - name: Manage the RHEL web console
      hosts: managed-node-01.example.com
      tasks:
        - name: Install RHEL web console
          ansible.builtin.include_role:
            name: rhel-system-roles.cockpit
          vars:
            cockpit_packages: default
            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. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

Chapter 9. Setting a custom cryptographic policy by using the 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.

9.1. Setting a custom cryptographic policy by using the crypto_policies RHEL 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

Procedure

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

    ---
    - name: Configure crypto policies
      hosts: managed-node-01.example.com
      tasks:
        - name: Configure crypto policies
          ansible.builtin.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 setting causes the system to reboot after the system role changes the cryptographic policy.

  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml
Warning

Because the FIPS:OSPP system-wide subpolicy contains further restrictions for cryptographic algorithms required by the Common Criteria (CC) certification, the system is less interoperable after you set it. For example, you cannot use RSA and DH keys shorter than 3072 bits, additional SSH algorithms, and several TLS groups. Setting FIPS:OSPP also prevents connecting to Red Hat Content Delivery Network (CDN) structure. Furthermore, you cannot integrate Active Directory (AD) into the IdM deployments that use FIPS:OSPP, communication between RHEL hosts using FIPS:OSPP and AD domains might not work, or some AD accounts might not be able to authenticate.

Note that your system is not CC-compliant after you set the FIPS:OSPP cryptographic subpolicy. The only correct way to make your RHEL system compliant with the CC standard is through the installation of the cc-config package. See the Common Criteria section in the Compliance Activities and Government Standards Knowledgebase article for a list of certified RHEL versions, validation reports, and links to CC guides hosted at the National Information Assurance Partnership (NIAP) website.

Verification

  1. On the control node, create another playbook named, for example, verify_playbook.yml:

    ---
    - name: Verification
      hosts: managed-node-01.example.com
      tasks:
        - name: Verify active crypto policy
          ansible.builtin.include_role:
            name: rhel-system-roles.crypto_policies
        - debug:
            var: crypto_policies_active
  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/verify_playbook.yml
  3. Run the playbook:

    $ ansible-playbook ~/verify_playbook.yml
    TASK [debug] **************************
    ok: [host] => {
        "crypto_policies_active": "FUTURE"
    }

    The crypto_policies_active variable shows the policy active on the managed node.

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.crypto_policies/README.md file
  • /usr/share/doc/rhel-system-roles/crypto_policies/ directory

Chapter 10. Configuring firewalld by using the RHEL system role

You can use the firewall RHEL 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 RHEL system role applies the firewalld parameters to the managed node immediately and makes them persistent across reboots.

10.1. 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 RHEL system role, and also the reference documentation.

To apply the firewalld parameters on one or more systems in an automated fashion, use the firewall RHEL 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

10.2. Resetting the firewalld settings by using the firewall 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 RHEL 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

Procedure

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

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

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.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 file
  • /usr/share/doc/rhel-system-roles/firewall/ directory

10.3. Forwarding incoming traffic in firewalld from one local port to a different local port by using the firewall 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

Procedure

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

    ---
    - name: Configure firewalld
      hosts: managed-node-01.example.com
      tasks:
        - name: Forward incoming traffic on port 8080 to 443
          ansible.builtin.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 --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.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 file
  • /usr/share/doc/rhel-system-roles/firewall/ directory

10.4. Managing ports in firewalld by using the firewall RHEL system role

You can use the firewall RHEL 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

Procedure

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

    ---
    - name: Configure firewalld
      hosts: managed-node-01.example.com
      tasks:
        - name: Allow incoming HTTPS traffic to the local host
          ansible.builtin.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 --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.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 file
  • /usr/share/doc/rhel-system-roles/firewall/ directory

10.5. Configuring a firewalld DMZ zone by using the firewall RHEL system role

As a system administrator, you can use the firewall RHEL 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

Procedure

  1. Create a playbook file, for example ~/playbook.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
          ansible.builtin.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 --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.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 file
  • /usr/share/doc/rhel-system-roles/firewall/ directory

Chapter 11. Configuring a high-availability cluster by using the 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.

11.1. Variables of the ha_cluster RHEL system role

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 must 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_enable_repos_resilient_storage
(RHEL 9.4 and later) A boolean flag that enables the repositories containing resilient storage packages, such as dlm or gfs2. For this option to take effect, ha_cluster_enable_repos must be set to true. The default value of this variable is false.
ha_cluster_manage_firewall

(RHEL 9.2 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 9.2, 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 9.2 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 9.3 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 9.2 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 9.1 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 9.1 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 9.1 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 9.2 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 9.1 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 9.1 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_node_options

(RHEL 9.4 and later) This variable defines various settings which vary from cluster node to cluster node. It sets the options for the specified nodes, but does not specify which nodes form the cluster. You specify which nodes form the cluster with the hosts parameter in an inventory or a playbook.

The items you configure with this variable are as follows:

  • node_name (mandatory) - Name of the node for which to define Pacemaker node attributes.
  • attributes (optional) - List of sets of Pacemaker node attributes for the node. Currently no more than one set for each node is supported.

The structure of the ha_cluster_node_options variable is as follows:

ha_cluster_node_options:
  - node_name: node1
    attributes:
      - attrs:
          - name: attribute1
            value: value1_node1
          - name: attribute2
            value: value2_node1
  - node_name: node2
    attributes:
      - attrs:
          - name: attribute1
            value: value1_node2
          - name: attribute2
            value: value2_node2

By default, no node options are defined.

For an example ha_cluster System Role playbook that includes node options configuration, see Configuring a high availability cluster with node attributes.

ha_cluster_resource_primitives

This variable defines pacemaker resources configured by the system role, including fencing resources. You can configure the following items for each resource:

  • id (mandatory) - ID of a resource.
  • agent (mandatory) - Name of a resource or fencing 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 fencing 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 9.3 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 fencing 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 9.3 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 9.3 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_stonith_levels

(RHEL 9.4 and later) This variable defines STONITH levels, also known as fencing topology. Fencing levels configure a cluster to use multiple devices to fence nodes. You can define alternative devices in case one device fails and you can require multiple devices to all be executed successfully to consider a node successfully fenced. For more information on fencing levels, see Configuring fencing levels in Configuring and managing high availability clusters.

You can configure the following items when defining fencing levels:

  • level (mandatory) - Order in which to attempt the fencing level. Pacemaker attempts levels in ascending order until one succeeds.
  • target (optional) - Name of a node this level applies to.
  • You must specify one of the following three selections:

    • target_pattern - POSIX extended regular expression matching the names of the nodes this level applies to.
    • target_attribute - Name of a node attribute that is set for the node this level applies to.
    • target_attribute and target_value - Name and value of a node attribute that is set for the node this level applies to.
  • resouce_ids (mandatory) - List of fencing resources that must all be tried for this level.

    By default, no fencing levels are defined.

The structure of the fencing levels definition that you configure with the ha_cluster System Role is as follows:

ha_cluster_stonith_levels:
  - level: 1..9
    target: node_name
    target_pattern: node_name_regular_expression
    target_attribute: node_attribute_name
    target_value: node_attribute_value
    resource_ids:
      - fence_device_1
      - fence_device_2
  - level: 1..9
    target: node_name
    target_pattern: node_name_regular_expression
    target_attribute: node_attribute_name
    target_value: node_attribute_value
    resource_ids:
      - fence_device_1
      - fence_device_2

For an example ha_cluster System Role playbook that configures fencing defaults, see Configuring a high availability cluster with fencing levels.

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 9.2 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.

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.ha_cluster/README.md file
  • /usr/share/doc/rhel-system-roles/ha_cluster/ directory

11.2. Specifying an inventory for the ha_cluster RHEL 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.

11.2.1. 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

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.ha_cluster/README.md file
  • /usr/share/doc/rhel-system-roles/ha_cluster/ directory

11.2.2. Configuring watchdog and SBD devices in an inventory

(RHEL 9.1 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 Variables of the ha_cluster system role.

For each node in an inventory, you can optionally specify the following items:

  • sbd_watchdog_modules (optional) - (RHEL 9.3 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 9.3 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.

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.ha_cluster/README.md file
  • /usr/share/doc/rhel-system-roles/ha_cluster/ directory

11.3. Creating pcsd TLS certificates and key files for a high availability cluster

(RHEL 9.2 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.

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.

Prerequisites

Procedure

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

    ---
    - name: Create TLS certificates and key files in a high availability cluster
      hosts: node1 node2
      roles:
        - rhel-system-roles.ha_cluster
      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

    This playbook 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.

    When creating your playbook file for production, vault encrypt the password, as described in Encrypting content with Ansible Vault.

  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

11.4. 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.

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.

Prerequisites

Procedure

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

    ---
    - name: Create a high availability cluster with no fencing and which runs no resources
      hosts: node1 node2
      roles:
        - rhel-system-roles.ha_cluster
      vars:
        ha_cluster_cluster_name: my-new-cluster
        ha_cluster_hacluster_password: <password>
        ha_cluster_manage_firewall: true
        ha_cluster_manage_selinux: true

    This example playbook file configures a cluster running the firewalld and selinux services with no fencing configured and which runs no resources.

    When creating your playbook file for production, vault encrypt the password, as described in Encrypting content with Ansible Vault.

  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.ha_cluster/README.md file
  • /usr/share/doc/rhel-system-roles/ha_cluster/ directory

11.5. 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.

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.

Prerequisites

Procedure

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

    ---
    - name: Create a high availability cluster that includes a fencing device and resources
      hosts: node1 node2
      roles:
        - rhel-system-roles.ha_cluster
      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

    This 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.

    When creating your playbook file for production, vault encrypt the password, as described in Encrypting content with Ansible Vault.

  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.ha_cluster/README.md file
  • /usr/share/doc/rhel-system-roles/ha_cluster/ directory

11.6. Configuring a high availability cluster with resource and resource operation defaults

(RHEL 9.3 and later) The following procedure uses the ha_cluster system role to create a high availability cluster that defines resource and resource operation defaults.

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.

Prerequisites

Procedure

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

    ---
    - name: Create a high availability cluster that defines resource and resource operation defaults
      hosts: node1 node2
      roles:
        - rhel-system-roles.ha_cluster
      vars:
        ha_cluster_cluster_name: my-new-cluster
        ha_cluster_hacluster_password: <password>
        ha_cluster_manage_firewall: true
        ha_cluster_manage_selinux: true
        # 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

    This example playbook file configures a cluster running the firewalld and selinux services. The cluster includes resource and resource operation defaults.

    When creating your playbook file for production, vault encrypt the password, as described in Encrypting content with Ansible Vault.

  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.ha_cluster/README.md file
  • /usr/share/doc/rhel-system-roles/ha_cluster/ directory

11.7. Configuring a high availability cluster with fencing levels

(RHEL 9.4 and later) The following procedure uses the ha_cluster System Role to create a high availability cluster that defines fencing levels.

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
        ha_cluster_manage_firewall: true
        ha_cluster_manage_selinux: true
        ha_cluster_resource_primitives:
          - id: apc1
            agent: 'stonith:fence_apc_snmp'
            instance_attrs:
              - attrs:
                  - name: ip
                    value: apc1.example.com
                  - name: username
                    value: user
                  - name: password
                    value: secret
                  - name: pcmk_host_map
                    value: node1:1;node2:2
          - id: apc2
            agent: 'stonith:fence_apc_snmp'
            instance_attrs:
              - attrs:
                  - name: ip
                    value: apc2.example.com
                  - name: username
                    value: user
                  - name: password
                    value: secret
                  - name: pcmk_host_map
                    value: node1:1;node2:2
        # Nodes have redundant power supplies, apc1 and apc2. Cluster must
        # ensure that when attempting to reboot a node, both power supplies
        # are turned off before either power supply is turned back on.
        ha_cluster_stonith_levels:
          - level: 1
            target: node1
            resource_ids:
              - apc1
              - apc2
          - level: 1
            target: node2
            resource_ids:
              - apc1
              - apc2
    
      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

11.8. 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.

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.

Prerequisites

Procedure

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

    ---
    - name: Create a high availability cluster with resource constraints
      hosts: node1 node2
      roles:
        - rhel-system-roles.ha_cluster
      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

    This 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.

    When creating your playbook file for production, vault encrypt the password, as described in Encrypting content with Ansible Vault.

  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.ha_cluster/README.md file
  • /usr/share/doc/rhel-system-roles/ha_cluster/ directory

11.9. Configuring Corosync values in a high availability cluster

(RHEL 9.1 and later) The following procedure uses the ha_cluster system role to create a high availability cluster that configures Corosync values.

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.

Prerequisites

Procedure

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

    ---
    - name: Create a high availability cluster that configures Corosync values
      hosts: node1 node2
      roles:
        - rhel-system-roles.ha_cluster
      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

    This example playbook file configures a cluster running the firewalld and selinux services that configures Corosync properties.

    When creating your playbook file for production, Vault encrypt the password, as described in Encrypting content with Ansible Vault.

  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.ha_cluster/README.md file
  • /usr/share/doc/rhel-system-roles/ha_cluster/ directory

11.10. Configuring a high availability cluster with SBD node fencing

(RHEL 9.1 and later) The following procedure uses the ha_cluster system role to create a high availability cluster that uses SBD node fencing.

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 9.3 and later) as described in Configuring watchdog and SBD devices in an inventory.

Prerequisites

Procedure

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

    ---
    - name: Create a high availability cluster that uses SBD node fencing
      hosts: node1 node2
      roles:
        - rhel-system-roles.ha_cluster
      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

    This example playbook file configures a cluster running the firewalld and selinux services that uses SBD fencing and creates the SBD Stonith resource.

    When creating your playbook file for production, vault encrypt the password, as described in Encrypting content with Ansible Vault.

  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.ha_cluster/README.md file
  • /usr/share/doc/rhel-system-roles/ha_cluster/ directory

11.11. Configuring a high availability cluster using a quorum device

(RHEL 9.2 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.

11.11.1. 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.

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.

Prerequisites

Procedure

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

    ---
    - name: Configure a quorum device
      hosts: nodeQ
      roles:
        - rhel-system-roles.ha_cluster
      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

    This example playbook file configures a quorum device on a system running the firewalld and selinux services.

    When creating your playbook file for production, vault encrypt the password, as described in Encrypting content with Ansible Vault.

  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.ha_cluster/README.md file
  • /usr/share/doc/rhel-system-roles/ha_cluster/ directory

11.11.2. Configuring a cluster to use a quorum device

To configure a cluster to use a quorum device, follow these steps.

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.

Prerequisites

Procedure

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

    ---
    - name: Configure a cluster to use a quorum device
      hosts: node1 node2
      roles:
        - rhel-system-roles.ha_cluster
      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

    This example playbook file configures a cluster running the firewalld and selinux services that uses a quorum device.

    When creating your playbook file for production, vault encrypt the password, as described in Encrypting content with Ansible Vault.

  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.ha_cluster/README.md file
  • /usr/share/doc/rhel-system-roles/ha_cluster/ directory

11.12. Configuring a high availability cluster with node attributes

(RHEL 9.4 and later) The following procedure uses the ha_cluster System Role to create a high availability cluster that configures node attributes.

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 node attributes configured for the nodes in the cluster.

    - 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_node_options:
          - node_name: node1
            attributes:
              - attrs:
                  - name: attribute1
                    value: value1A
                  - name: attribute2
                    value: value2A
          - node_name: node2
            attributes:
              - attrs:
                  - name: attribute1
                    value: value1B
                  - name: attribute2
                    value: value2B
    
      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

11.13. Configuring an Apache HTTP server in a high availability cluster with the ha_cluster RHEL 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.

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.

Prerequisites

Procedure

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

    ---
    - name: Configure active/passive Apache server in a high availability cluster
      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

    This 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.

    When creating your playbook file for production, vault encrypt the password, as described in Encrypting content with Ansible Vault.

  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml
  4. 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

    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

Verification

  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.

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.ha_cluster/README.md file
  • /usr/share/doc/rhel-system-roles/ha_cluster/ directory

Chapter 12. Configuring the systemd journal by using the RHEL system role

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

12.1. Configuring persistent logging by using the journald RHEL system role

As a system administrator, you can configure persistent logging by using the journald RHEL system role. The following example shows how to set up the journald RHEL 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

Procedure

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

    ---
    - name: Configure persistent logging
      hosts: managed-node-01.example.com
      vars:
        journald_persistent: true
        journald_max_disk_size: 2048
        journald_per_user: true
        journald_sync_interval: 1
      roles:
        - rhel-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. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.journald/README.md file
  • /usr/share/doc/rhel-system-roles/journald/ directory

Chapter 13. Configuring automatic crash dumps by using the 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 9.

Using the kdump role enables you to specify where to save the contents of the system’s memory for later analysis.

13.1. Configuring the kernel crash dumping mechanism by using the kdump RHEL system role

You can set basic kernel dump parameters on multiple systems by using the kdump system role by running an Ansible playbook.

Warning

The kdump Systeme 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

Procedure

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

    ---
    - hosts: managed-node-01.example.com
      roles:
        - rhel-system-roles.kdump
      vars:
        kdump_path: /var/crash
  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.kdump/README.md file
  • /usr/share/doc/rhel-system-roles/kdump/ directory

Chapter 14. Configuring kernel parameters permanently by using the RHEL system role

You can use the kernel_settings RHEL system 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.

14.1. Introduction to the kernel_settings RHEL system 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 RHEL 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

14.2. Applying selected kernel parameters by using the kernel_settings RHEL system 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

Procedure

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

    ---
    - name: Configure kernel settings
      hosts: managed-node-01.example.com
      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
    • name: optional key which associates an arbitrary string with the play as a label and identifies what the play is for.
    • hosts: key in the play which 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.
    • vars: section of the playbook which represents a list of variables containing selected kernel parameter names and values to which they have to be set.
    • role: key which specifies what RHEL 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.

  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml
  4. 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 15. Configuring logging by using the RHEL system role

As a system administrator, you can use the logging RHEL system role to configure a Red Hat Enterprise Linux host as a logging server to collect logs from many client systems.

15.1. The logging RHEL system role

With the logging RHEL system role, you can deploy logging configurations on local and remote hosts.

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 RHEL 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.

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.logging/README.md file
  • /usr/share/doc/rhel-system-roles/logging/ directory
  • RHEL system roles

15.2. Applying a local logging RHEL 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

Note

You do not have to have the rsyslog package installed, because the RHEL system role installs rsyslog when deployed.

Procedure

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

    ---
    - name: Deploying basics input and implicit files output
      hosts: managed-node-01.example.com
      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. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/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 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.

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.logging/README.md file
  • /usr/share/doc/rhel-system-roles/logging/ directory

15.3. Filtering logs in a local logging RHEL system role

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

Prerequisites

Note

You do not have to have the rsyslog package installed, because the RHEL system role installs rsyslog when deployed.

Procedure

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

    ---
    - name: Deploying files input and configured files output
      hosts: managed-node-01.example.com
      roles:
        - rhel-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. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/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

  • /usr/share/ansible/roles/rhel-system-roles.logging/README.md file
  • /usr/share/doc/rhel-system-roles/logging/ directory

15.4. Applying a remote logging solution by using the logging RHEL 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

Note

You do not have to have the rsyslog package installed, because the RHEL system role installs rsyslog when deployed.

Procedure

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

    ---
    - name: Deploying remote input and remote_files output
      hosts: managed-node-01.example.com
      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: managed-node-02.example.com
      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. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

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

  • /usr/share/ansible/roles/rhel-system-roles.logging/README.md file
  • /usr/share/doc/rhel-system-roles/logging/ directory

15.5. Using the logging RHEL 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.

15.5.1. Configuring client logging with TLS

You can use an Ansible playbook with the logging RHEL 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 RHEL system role in the playbook to create the certificate. The logging RHEL 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 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 are enrolled in an IdM domain.
  • If the logging server you want to configure on the manage node runs RHEL 9.2 or later and the FIPS mode is enabled, clients must either support the Extended Master Secret (EMS) extension or use TLS 1.3. TLS 1.2 connections without EMS fail. For more information, see the TLS extension "Extended Master Secret" enforced Knowledgebase article.

Procedure

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

    ---
    - name: Deploying files input and forwards output with certs
      hosts: managed-node-01.example.com
      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 RHEL system 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. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

15.5.2. Configuring server logging with TLS

You can use an Ansible playbook with the logging RHEL 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 RHEL system role in the playbook to create the certificate. The logging RHEL 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 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 are enrolled in an IdM domain.
  • If the logging server you want to configure on the manage node runs RHEL 9.2 or later and the FIPS mode is enabled, clients must either support the Extended Master Secret (EMS) extension or use TLS 1.3. TLS 1.2 connections without EMS fail. For more information, see the TLS extension "Extended Master Secret" enforced Knowledgebase article.

Procedure

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

    ---
    - name: Deploying remote input and remote_files output with certs
      hosts: managed-node-01.example.com
      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 RHEL system 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. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

15.6. Using the logging RHEL 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 RHEL system role to configure the logging system to reliably send and receive log entries.

15.6.1. Configuring client logging with RELP

You can use the logging RHEL 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

Procedure

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

    ---
    - name: Deploying basic input and relp output
      hosts: managed-node-01.example.com
      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 playbook 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. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.logging/README.md file
  • /usr/share/doc/rhel-system-roles/logging/ directory

15.6.2. Configuring server logging with RELP

You can use the logging RHEL 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

Procedure

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

    ---
    - name: Deploying remote input and remote_files output
      hosts: managed-node-01.example.com
      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. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.logging/README.md file
  • /usr/share/doc/rhel-system-roles/logging/ directory

Chapter 16. Monitoring performance by using the RHEL system role

As a system administrator, you can use the metrics RHEL system role to monitor the performance of a system.

16.1. Introduction to the metrics RHEL 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.

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.metrics/README.md file
  • /usr/share/doc/rhel-system-roles/metrics/ directory

16.2. Using the metrics RHEL 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

  • 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.
  • localhost is configured in the inventory file on the control node:

    localhost ansible_connection=local

Procedure

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

    ---
    - name: Manage metrics
      hosts: localhost
      roles:
        - rhel-system-roles.metrics
      vars:
        metrics_graph_service: yes
        metrics_manage_firewall: true
        metrics_manage_selinux: true

    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.

  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Verification

  • To view visualization of the metrics being collected on your machine, access the grafana web interface as described in Accessing the Grafana web UI.

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.metrics/README.md file
  • /usr/share/doc/rhel-system-roles/metrics/ directory

16.3. Using the metrics RHEL 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

Procedure

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

    ---
    - name: Configure a fleet of machines to monitor themselves
      hosts: managed-node-01.example.com
      roles:
        - rhel-system-roles.metrics
      vars:
        metrics_retention_days: 0
        metrics_manage_firewall: true
        metrics_manage_selinux: true

    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. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.metrics/README.md file
  • /usr/share/doc/rhel-system-roles/metrics/ directory

16.4. Using the metrics RHEL system role to monitor a fleet of machines centrally using 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

  • 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.
  • localhost is configured in the inventory file on the control node:

    localhost ansible_connection=local

Procedure

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

    - name: Set up your local machine to centrally monitor a fleet of machines
      hosts: localhost
      roles:
        - rhel-system-roles.metrics
      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

    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.

  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Verification

  • 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.

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.metrics/README.md file
  • /usr/share/doc/rhel-system-roles/metrics/ directory

16.5. Setting up authentication while monitoring a system by using the metrics RHEL 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 by using the scram-sha-256 authentication mechanism. This procedure describes how to setup authentication by using the metrics RHEL system role.

Prerequisites

Procedure

  1. Edit an existing playbook file, for example ~/playbook.yml, and add the authentication-related variables:

    ---
    - name: Set up authentication by using the scram-sha-256 authentication mechanism
      hosts: managed-node-01.example.com
      roles:
        - rhel-system-roles.metrics
      vars:
        metrics_retention_days: 0
        metrics_manage_firewall: true
        metrics_manage_selinux: true
        metrics_username: <username>
        metrics_password: <password>
  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Verification

  • Verify the sasl configuration:

    # pminfo -f -h "pcp://managed-node-01.example.com?username=<username>" disk.dev.read
    Password: <password>
    disk.dev.read
    inst [0 or "sda"] value 19540

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.metrics/README.md file
  • /usr/share/doc/rhel-system-roles/metrics/ directory

16.6. Using the metrics RHEL 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

Procedure

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

    ---
    - name: Configure and enable metrics collection for Microsoft SQL Server
      hosts: localhost
      roles:
        - rhel-system-roles.metrics
      vars:
        metrics_from_mssql: true
        metrics_manage_firewall: true
        metrics_manage_selinux: true

    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. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Verification

  • Use the pcp command to verify that SQL Server PMDA agent (mssql) is loaded and running:

    # pcp
    platform: Linux sqlserver.example.com 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/sqlserver.example.com/20200326.16.31
         pmie: primary engine: /var/log/pcp/pmie/sqlserver.example.com/pmie.log

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.metrics/README.md file
  • /usr/share/doc/rhel-system-roles/metrics/ directory

Chapter 17. Configuring Microsoft SQL Server by using the RHEL system 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 Red Hat Enterprise Linux host with recommended settings to run the SQL Server workloads.

17.1. Installing and configuring SQL server by using the microsoft.sql.server system 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

  • 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.
  • Minimum 2 GB RAM
  • The ansible-collection-microsoft-sql package is installed on the managed node.
  • The managed node uses one of the following versions: RHEL 7.9, RHEL 8, RHEL 9.4 or later.

Procedure

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

    ---
    - name: Install and configure SQL Server
      hosts: managed-node-01.example.com
      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
  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/microsoft.sql-server/README.md file

17.2. Installing and configuring SQL server by using the microsoft.sql.server system role with the certificate RHEL system 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 by using the certificate system role.

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.

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.
  • Minimum 2 GB RAM
  • The ansible-collection-microsoft-sql package is installed on the managed node.
  • The managed nodes are enrolled in a Red Hat Identity Management (IdM) domain.
  • The managed node uses one of the following versions: RHEL 7.9, RHEL 8, RHEL 9.4 or later.

Procedure

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

    ---
    - name: Install and configure SQL Server
      hosts: managed-node-01.example.com
      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
  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

17.3. Setting up custom storage paths for data and logs

To store your data or logs in a different directory than the default one, specify the custom storage path using the mssql_datadir, mssql_datadir_mode, mssql_logdir, and mssql_logdir_mode variables in an existing playbook. When you define a custom path, the role creates the provided directory and ensures correct permissions and ownership for it.

Important

If you later decide to remove the variables, the storage paths will not change back to the default ones but will store the data or logs in the latest defined paths.

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.
  • Minimum 2 GB RAM
  • The ansible-collection-microsoft-sql package is installed on the managed node.
  • The managed node uses one of the following versions: RHEL 7.9, RHEL 8, RHEL 9.4 or later.

Procedure

  1. Edit an existing playbook file, for example ~/playbook.yml, and add the storage and log-related variables:

    ---
    - name: Install and configure SQL Server
      hosts: managed-node-01.example.com
      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
        mssql_datadir: /var/lib/mssql/
        mssql_datadir_mode: '0700'
        mssql_logdir: /var/log/mssql/
        mssql_logdir_mode: '0700'

    Enter the permission modes in single quotation marks so that Ansible parses it as a string and not as an octal number.

    If you do not specify the mode and the destination directory does not exist, the role uses the default umask on the system when setting the mode. If you do not specify the mode and the destination directory does exist, the role uses the mode of the existing directory.

  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/microsoft.sql-server/README.md file

Chapter 18. Configuring NBDE by using RHEL system roles

18.1. Introduction to the nbde_client and nbde_server RHEL 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.

You can use Ansible roles for automated deployments of Policy-Based Decryption (PBD) solutions using Clevis and Tang. The rhel-system-roles package contains these system roles, the 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

  • /usr/share/ansible/roles/rhel-system-roles.nbde_server/README.md file
  • /usr/share/ansible/roles/rhel-system-roles.nbde_client/README.md file
  • /usr/share/doc/rhel-system-roles/nbde_server/ directory
  • /usr/share/doc/rhel-system-roles/nbde_client/ directory

18.2. Using the nbde_server RHEL system role for setting up multiple Tang servers

Follow the steps to prepare and apply an Ansible playbook containing your Tang server settings.

Prerequisites

Procedure

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

    ---
    - hosts: managed-node-01.example.com
      roles:
        - rhel-system-roles.nbde_server
      vars:
        nbde_server_rotate_keys: yes
        nbde_server_manage_firewall: true
        nbde_server_manage_selinux: true

    This example playbook ensures deploying of your Tang server and a key rotation.

    When 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.

  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Verification

  • 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, enter:

    # grubby --update-kernel=ALL --args="rd.neednet=1"

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.nbde_server/README.md file
  • /usr/share/doc/rhel-system-roles/nbde_server/ directory

18.3. Setting up multiple Clevis clients by using the nbde_client RHEL system role

With the nbde_client RHEL system role, you can prepare and apply an Ansible playbook that contains your Clevis client settings on multiple systems.

Note

The nbde_client system role supports only Tang bindings. Therefore, you cannot use it for TPM2 bindings.

Prerequisites

Procedure

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

    - hosts: managed-node-01.example.com
      roles:
        - rhel-system-roles.nbde_client
      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

    This example playbook configures Clevis clients for automated unlocking of two LUKS-encrypted volumes when at least one of two Tang servers is available

    The nbde_client system role supports only scenarios with Dynamic Host Configuration Protocol (DHCP). To use NBDE for clients with static IP configuration use the following playbook:

    - hosts: managed-node-01.example.com
      roles:
        - rhel-system-roles.nbde_client
      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
      tasks:
        - name: Configure a client with a static IP address during early boot
          ansible.builtin.command:
            cmd: grubby --update-kernel=ALL --args='GRUB_CMDLINE_LINUX_DEFAULT="ip={{ <ansible_default_ipv4.address> }}::{{ <ansible_default_ipv4.gateway> }}:{{ <ansible_default_ipv4.netmask> }}::{{ <ansible_default_ipv4.alias> }}:none"'

    In this playbook, replace the <ansible_default_ipv4.*> strings with IP addresses of your network, for example: ip={{ 192.0.2.10 }}::{{ 192.0.2.1 }}:{{ 255.255.255.0 }}::{{ ens3 }}:none.

  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

Chapter 19. Configuring network settings by using the RHEL system role

Administrators can automate network-related configuration and management tasks by using the network RHEL system role.

19.1. 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.

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.
  • 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 ~/playbook.yml, with the following content:

    ---
    - name: Configure the network
      hosts: managed-node-01.example.com
      tasks:
        - name: Configure an Ethernet connection with static IP
          ansible.builtin.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 --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

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

19.2. 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=

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.
  • 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 ~/playbook.yml, with the following content:

    ---
    - name: Configure the network
      hosts: managed-node-01.example.com
      tasks:
        - name: Configure an Ethernet connection with static IP
          ansible.builtin.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 --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

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

19.3. 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.

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.
  • 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 ~/playbook.yml, with the following content:

    ---
    - name: Configure the network
      hosts: managed-node-01.example.com
      tasks:
        - name: Configure an Ethernet connection with dynamic IP
          ansible.builtin.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 --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

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

19.4. 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=

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.
  • 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 ~/playbook.yml, with the following content:

    ---
    - name: Configure the network
      hosts: managed-node-01.example.com
      tasks:
        - name: Configure an Ethernet connection with dynamic IP
          ansible.builtin.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 defines that Ansible applies the play to devices that match PCI ID 0000:00:0[1-3].0, but not 0000:00:02.0.

  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

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

19.5. 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.

Prerequisites

Procedure

  1. Create a playbook file, for example ~/playbook.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
          ansible.builtin.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 --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

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

19.6. 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.

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.
  • Two or more physical or virtual network devices are installed on the server.

Procedure

  1. Create a playbook file, for example ~/playbook.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
          ansible.builtin.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 --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

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

19.7. 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.

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.
  • Two or more physical or virtual network devices are installed on the server.

Procedure

  1. Create a playbook file, for example ~/playbook.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
          ansible.builtin.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 --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

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

19.8. 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 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.
  • 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 ~/playbook.yml, with the following content:

    ---
    - name: Configure the network
      hosts: managed-node-01.example.com
      tasks:
        - name: Configure IPoIB
          ansible.builtin.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 --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.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
  • /usr/share/doc/rhel-system-roles/network/ directory

19.9. 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 network RHEL system role.

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 them.
  • 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 ~/playbook.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
          ansible.builtin.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 --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Verification

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

    1. Install the traceroute package:

      # dnf 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:

      # dnf 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
  • /usr/share/doc/rhel-system-roles/network/ directory

19.10. 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.

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 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 ~/playbook.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
          ansible.builtin.copy:
            src: "/srv/data/client.key"
            dest: "/etc/pki/tls/private/client.key"
            mode: 0600
    
        - name: Copy client certificate for 802.1X authentication
          ansible.builtin.copy:
            src: "/srv/data/client.crt"
            dest: "/etc/pki/tls/certs/client.crt"
    
        - name: Copy CA certificate for 802.1X authentication
          ansible.builtin.copy:
            src: "/srv/data/ca.crt"
            dest: "/etc/pki/ca-trust/source/anchors/ca.crt"
    
        - name: Configure connection
          ansible.builtin.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 --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

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

19.11. Configuring a wifi connection with 802.1X network authentication by using the network RHEL system role

Using RHEL system role, you can automate the creation of a wifi connection. For example, you can remotely add a wireless connection profile for the wlp1s0 interface using an Ansible Playbook. The created profile uses the 802.1X standard to authenticate the client to a wifi network. The playbook configures the connection profile to use DHCP. To configure static IP settings, adapt the parameters in the ip dictionary accordingly.

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 network supports 802.1X network authentication.
  • You installed the wpa_supplicant package on the managed node.
  • DHCP is available in the network of the managed node.
  • 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 CA certificate is stored in the /srv/data/ca.crt file.

Procedure

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

    ---
    - name: Configure a wifi connection with 802.1X authentication
      hosts: managed-node-01.example.com
      tasks:
        - name: Copy client key for 802.1X authentication
          ansible.builtin.copy:
            src: "/srv/data/client.key"
            dest: "/etc/pki/tls/private/client.key"
            mode: 0400
    
        - name: Copy client certificate for 802.1X authentication
          ansible.builtin.copy:
            src: "/srv/data/client.crt"
            dest: "/etc/pki/tls/certs/client.crt"
    
        - name: Copy CA certificate for 802.1X authentication
          ansible.builtin.copy:
            src: "/srv/data/ca.crt"
            dest: "/etc/pki/ca-trust/source/anchors/ca.crt"
    
        - block:
            - ansible.builtin.import_role:
                name: rhel-system-roles.network
              vars:
                network_connections:
                  - name: Configure the Example-wifi profile
                    interface_name: wlp1s0
                    state: up
                    type: wireless
                    autoconnect: yes
                    ip:
                      dhcp4: true
                      auto6: true
                    wireless:
                      ssid: "Example-wifi"
                      key_mgmt: "wpa-eap"
                    ieee802_1x:
                      identity: "user_name"
                      eap: tls
                      private_key: "/etc/pki/tls/client.key"
                      private_key_password: "password"
                      private_key_password_flags: none
                      client_cert: "/etc/pki/tls/client.pem"
                      ca_cert: "/etc/pki/tls/cacert.pem"
                      domain_suffix_match: "example.com"

    These settings define a wifi connection profile for the wlp1s0 interface. The profile uses 802.1X standard to authenticate the client to the wifi network. 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 --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

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

19.12. Setting the default gateway on an existing connection by using the network RHEL system role

In most situations, administrators set the default gateway when they create a connection. However, you can also set or update the default gateway setting on a previously created connection by using the network RHEL system role to set the default gateway.

Important

When you run a play that uses the network RHEL system role and if the setting values do not match the values specified in the play, the role overrides the existing connection profile with the same name. To prevent resetting these values to their defaults, always specify the whole configuration of the network connection profile in the play, even if the configuration, for example the IP configuration, already exists.

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

Prerequisites

Procedure

  1. Create a playbook file, for example ~/playbook.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
          ansible.builtin.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 --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

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

19.13. 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 and if the setting values do not match the values specified in the play, the role overrides the existing connection profile with the same name. To prevent resetting these values to their defaults, always specify the whole configuration of the network connection profile in the play, even if the configuration, for example the IP configuration, already exists.

Prerequisites

Procedure

  1. Create a playbook file, for example ~/playbook.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
          ansible.builtin.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 --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.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
  • /usr/share/doc/rhel-system-roles/network/ directory

19.14. 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 and if the setting values do not match the values specified in the play, the role overrides the existing connection profile with the same name. To prevent resetting these values to their defaults, always specify the whole configuration of the network connection profile in the play, even if the configuration, for example the IP configuration, already exists.

Prerequisites

Procedure

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

    ---
    - name: Configure the network
      hosts: managed-node-01.example.com
      tasks:
        - name: Configure an Ethernet connection with ethtool features
          ansible.builtin.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

    This playbook creates the enp1s0 connection profile with the following settings, or updates it if the profile already exists:

    • 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 --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

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

19.15. 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 and if the setting values do not match the values specified in the play, the role overrides the existing connection profile with the same name. To prevent resetting these values to their defaults, always specify the whole configuration of the network connection profile in the play, even if the configuration, for example the IP configuration, already exists.

Prerequisites

Procedure

  1. Create a playbook file, for example ~/playbook.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
          ansible.builtin.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

    This playbook creates the enp1s0 connection profile with the following settings, or updates it if the profile already exists:

    • 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 --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

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

19.16. Increasing the ring buffer size to reduce a high packet drop rate by using the network RHEL system role

Increase the size of an Ethernet device’s ring buffers if the packet drop rate causes applications to report a loss of data, timeouts, or other issues.

Ring buffers are circular buffers where an overflow overwrites existing data. The network card assigns a transmit (TX) and receive (RX) ring buffer. Receive ring buffers are shared between the device driver and the network interface controller (NIC). Data can move from NIC to the kernel through either hardware interrupts or software interrupts, also called SoftIRQs.

The kernel uses the RX ring buffer to store incoming packets until the device driver can process them. The device driver drains the RX ring, typically by using SoftIRQs, which puts the incoming packets into a kernel data structure called an sk_buff or skb to begin its journey through the kernel and up to the application that owns the relevant socket.

The kernel uses the TX ring buffer to hold outgoing packets which should be sent to the network. These ring buffers reside at the bottom of the stack and are a crucial point at which packet drop can occur, which in turn will adversely affect network performance.

Important

When you run a play that uses the network RHEL system role and if the setting values do not match the values specified in the play, the role overrides the existing connection profile with the same name. To prevent resetting these values to their defaults, always specify the whole configuration of the network connection profile in the play, even if the configuration, for example the IP configuration, already exists.

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.
  • You know the maximum ring buffer sizes that the device supports.

Procedure

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

    ---
    - name: Configure the network
      hosts: managed-node-01.example.com
      tasks:
        - name: Configure an Ethernet connection with increased ring buffer sizes
          ansible.builtin.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:
                  ring:
                    rx: 4096
                    tx: 4096
                state: up

    This playbook creates the enp1s0 connection profile with the following settings, or updates it if the profile already exists:

    • 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
    • Maximum number of ring buffer entries:

      • Receive (RX): 4096
      • Transmit (TX): 4096
  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

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

19.17. 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
  • /usr/share/doc/rhel-system-roles/network/ directory

Chapter 20. 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.

20.1. Creating a rootless container with bind mount

You can use the podman RHEL system role to create rootless containers with bind mount by running an Ansible playbook and with that, manage your application configuration.

Prerequisites

Procedure

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

    - hosts: managed-node-01.example.com
      vars:
        podman_create_host_directories: true
        podman_firewall:
          - port: 8080-8081/tcp
            state: enabled
          - port: 12340/tcp
            state: enabled
        podman_selinux_ports:
          - ports: 8080-8081
            setype: http_port_t
        podman_kube_specs:
          - state: started
            run_as_user: dbuser
            run_as_group: dbgroup
            kube_file_content:
              apiVersion: v1
              kind: Pod
              metadata:
                name: db
              spec:
                containers:
                  - name: db
                    image: quay.io/db/db:stable
                    ports:
                      - containerPort: 1234
                        hostPort: 12340
                    volumeMounts:
                      - mountPath: /var/lib/db:Z
                        name: db
                volumes:
                  - name: db
                    hostPath:
                      path: /var/lib/db
          - state: started
            run_as_user: webapp
            run_as_group: webapp
            kube_file_src: /path/to/webapp.yml
      roles:
        - linux-system-roles.podma

    This procedure creates a pod with two containers. The podman_kube_specs role variable describes a pod.

    • The run_as_user and run_as_group fields specify that containers are rootless.
    • The kube_file_content field containing a Kubernetes YAML file defines the first container named db. You can generate the Kubernetes YAML file using the podman kube generate command.

      • The db container is based on the quay.io/db/db:stable container image.
      • The db bind mount maps the /var/lib/db directory on the host to the /var/lib/db directory in the container. The Z flag labels the content with a private unshared label, therefore, only the db container can access the content.
    • The kube_file_src field defines the second container. The content of the /path/to/webapp.yml file on the controller node will be copied to the kube_file field on the managed node.
    • Set the podman_create_host_directories: true to create the directory on the host. This instructs the role to check the kube specification for hostPath volumes and create those directories on the host. If you need more control over the ownership and permissions, use podman_host_directories.
  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check --ask-vault-pass ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook --ask-vault-pass ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.podman/README.md file
  • /usr/share/doc/rhel-system-roles/podman/ directory

20.2. Creating a rootful container with Podman volume

You can use the podman RHEL system role to create a rootful container with a Podman volume by running an Ansible playbook and with that, manage your application configuration.

Prerequisites

Procedure

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

    - hosts: managed-node-01.example.com
      vars:
        podman_firewall:
          - port: 8080/tcp
            state: enabled
        podman_kube_specs:
          - state: started
            kube_file_content:
              apiVersion: v1
              kind: Pod
              metadata:
                name: ubi8-httpd
              spec:
                containers:
                  - name: ubi8-httpd
                    image: registry.access.redhat.com/ubi8/httpd-24
                    ports:
                      - containerPort: 8080
                        hostPort: 8080
                    volumeMounts:
                      - mountPath: /var/www/html:Z
                        name: ubi8-html
                volumes:
                  - name: ubi8-html
                    persistentVolumeClaim:
                      claimName: ubi8-html-volume
      roles:
        - linux-system-roles.podman

    The procedure creates a pod with one container. The podman_kube_specs role variable describes a pod.

    • By default, the podman role creates rootful containers.
    • The kube_file_content field containing a Kubernetes YAML file defines the container named ubi8-httpd.

      • The ubi8-httpd container is based on the registry.access.redhat.com/ubi8/httpd-24 container image.

        • The ubi8-html-volume maps the /var/www/html directory on the host to the container. The Z flag labels the content with a private unshared label, therefore, only the ubi8-httpd container can access the content.
        • The pod mounts the existing persistent volume named ubi8-html-volume with the mount path /var/www/html.
  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.podman/README.md file
  • /usr/share/doc/rhel-system-roles/podman/ directory

20.3. Creating a Quadlet application with secrets

You can use the podman RHEL system role to create a Quadlet application with secrets by running an Ansible playbook.

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 certificate and the corresponding private key that the web server in the container should use are stored in the ~/certificate.pem and ~/key.pem files.

Procedure

  1. Display the contents of the certificate and private key files:

    $ cat ~/certificate.pem
    -----BEGIN CERTIFICATE-----
    ...
    -----END CERTIFICATE-----
    
    $ cat ~/key.pem
    -----BEGIN PRIVATE KEY-----
    ...
    -----END PRIVATE KEY-----

    You require this information in a later step.

  2. Store your sensitive variables in an encrypted file:

    1. Create the vault:

      $ ansible-vault create vault.yml
      New Vault password: <vault_password>
      Confirm New Vault password: <vault_password>
    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format:

      root_password: <root_password>
      certificate: |-
        -----BEGIN CERTIFICATE-----
        ...
        -----END CERTIFICATE-----
      key: |-
        -----BEGIN PRIVATE KEY-----
        ...
        -----END PRIVATE KEY-----

      Ensure that all lines in the certificate and key variables start with two spaces.

    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.
  3. Create a playbook file, for example ~/playbook.yml, with the following content:

    - name: Deploy a wordpress CMS with MySQL database
      hosts: managed-node-01.example.com
      vars_files:
        - vault.yml
      tasks:
      - name: Create and run the container
        ansible.builtin.include_role:
          name: rhel-system-roles.podman
        vars:
          podman_create_host_directories: true
          podman_activate_systemd_unit: false
          podman_quadlet_specs:
            - name: quadlet-demo
              type: network
              file_content: |
                [Network]
                Subnet=192.168.30.0/24
                Gateway=192.168.30.1
                Label=app=wordpress
            - file_src: quadlet-demo-mysql.volume
            - template_src: quadlet-demo-mysql.container.j2
            - file_src: envoy-proxy-configmap.yml
            - file_src: quadlet-demo.yml
            - file_src: quadlet-demo.kube
              activate_systemd_unit: true
          podman_firewall:
            - port: 8000/tcp
              state: enabled
            - port: 9000/tcp
              state: enabled
          podman_secrets:
            - name: mysql-root-password-container
              state: present
              skip_existing: true
              data: "{{ root_password }}"
            - name: mysql-root-password-kube
              state: present
              skip_existing: true
              data: |
                apiVersion: v1
                data:
                  password: "{{ root_password | b64encode }}"
                kind: Secret
                metadata:
                  name: mysql-root-password-kube
            - name: envoy-certificates
              state: present
              skip_existing: true
              data: |
                apiVersion: v1
                data:
                  certificate.key: {{ key | b64encode }}
                  certificate.pem: {{ certificate | b64encode }}
                kind: Secret
                metadata:
                  name: envoy-certificates

    The procedure creates a WordPress content management system paired with a MySQL database. The podman_quadlet_specs role variable defines a set of configurations for the Quadlet, which refers to a group of containers or services that work together in a certain way. It includes the following specifications:

    • The Wordpress network is defined by the quadlet-demo network unit.
    • The volume configuration for MySQL container is defined by the file_src: quadlet-demo-mysql.volume field.
    • The template_src: quadlet-demo-mysql.container.j2 field is used to generate a configuration for the MySQL container.
    • Two YAML files follow: file_src: envoy-proxy-configmap.yml and file_src: quadlet-demo.yml. Note that .yml is not a valid Quadlet unit type, therefore these files will just be copied and not processed as a Quadlet specification.
    • The Wordpress and envoy proxy containers and configuration are defined by the file_src: quadlet-demo.kube field. The kube unit refers to the previous YAML files in the [Kube] section as Yaml=quadlet-demo.yml and ConfigMap=envoy-proxy-configmap.yml.
  4. Validate the playbook syntax:

    $ ansible-playbook --syntax-check --ask-vault-pass ~/playbook.yml

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

  5. Run the playbook:

    $ ansible-playbook --ask-vault-pass ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.podman/README.md file
  • /usr/share/doc/rhel-system-roles/podman/ directory

Chapter 21. Configuring Postfix MTA by using the RHEL system role

With the postfix RHEL system 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 RHEL system role, and also the reference documentation.

21.1. Using the postfix RHEL 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

Procedure

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

    ---
    - name: Manage postfix
      hosts: managed-node-01.example.com
      roles:
        - rhel-system-roles.postfix
      vars:
        postfix_conf:
          relay_domains: $mydestination
            relayhost: example.com
    • 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
    • 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>
    • 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.

    • 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 RHEL system role directly.

  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.postfix/README.md file
  • /usr/share/doc/rhel-system-roles/postfix/ directory

Chapter 22. Installing and configuring PostgreSQL by using the 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.

22.1. 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.

22.2. Configuring the PostgreSQL server by using the postgresql RHEL system role

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 playbook file, for example ~/playbook.yml, with the following content:

    ---
    - name: Manage PostgreSQL
      hosts: managed-node-01.example.com
      roles:
        - rhel-system-roles.postgresql
      vars:
        postgresql_version: "13"
  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.postgresql/README.md file
  • /usr/share/doc/rhel-system-roles/postgresql/ directory
  • Using PostgreSQL

Chapter 23. Registering the system by using the RHEL system role

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.

23.1. Introduction to the rhc RHEL 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) RHEL 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 RHEL system role, the system is connected to Insights. Additionally, with the rhc RHEL 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

23.2. Registering a system by using the rhc RHEL 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

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault:

      $ ansible-vault create vault.yml
      New Vault password: <password>
      Confirm New Vault password: <vault_password>
    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format:

      activationKey: <activation_key>
      username: <username>
      password: <password>
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.
  2. Create a playbook file, for example ~/playbook.yml, with the following content:

    • 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:
          - vault.yml
        roles:
          - role: rhel-system-roles.rhc
        vars:
          rhc_auth:
            activation_keys:
              keys:
                -  "{{ activationKey }}"
          rhc_organization: organizationID
    • 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:
          - vault.yml
        vars:
          rhc_auth:
            login:
              username: "{{ username }}"
              password: "{{ password }}"
        roles:
          - role: rhel-system-roles.rhc
  3. Validate the playbook syntax:

    $ ansible-playbook --syntax-check --ask-vault-pass ~/playbook.yml

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

  4. Run the playbook:

    $ ansible-playbook --ask-vault-pass ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.rhc/README.md file
  • /usr/share/doc/rhel-system-roles/rhc/ directory
  • Ansible Vault

23.3. Registering a system with Satellite by using the rhc RHEL 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

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault:

      $ ansible-vault create vault.yml
      New Vault password: <password>
      Confirm New Vault password: <vault_password>
    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format:

      activationKey: <activation_key>
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.
  2. Create a playbook file, for example ~/playbook.yml, with the following content:

    ---
    - name: Register to the custom registration server and CDN
      hosts: managed-node-01.example.com
      vars_files:
        - vault.yml
      roles:
        - role: rhel-system-roles.rhc
      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
  3. Validate the playbook syntax:

    $ ansible-playbook --syntax-check --ask-vault-pass ~/playbook.yml

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

  4. Run the playbook:

    $ ansible-playbook --ask-vault-pass ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.rhc/README.md file
  • /usr/share/doc/rhel-system-roles/rhc/ directory
  • Ansible Vault

23.4. Disabling the connection to Insights after the registration by using the rhc RHEL 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 RHEL system role, if not required.

Prerequisites

Procedure

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

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

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

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

23.5. Enabling repositories by using the rhc RHEL 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.
  • 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 ~/playbook.yml, with the following content:

    • To enable a repository:

      ---
      - name: Enable repository
        hosts: managed-node-01.example.com
        roles:
          - role: rhel-system-roles.rhc
        vars:
          rhc_repositories:
            - {name: "RepositoryName", state: enabled}
    • 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. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

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

23.6. Setting release versions by using the rhc RHEL 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.
  • 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 ~/playbook.yml, with the following content:

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

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

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

23.7. Using a proxy server when registering the host by using the rhc RHEL 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

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault:

      $ ansible-vault create vault.yml
      New Vault password: <password>
      Confirm New Vault password: <vault_password>
    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format:

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

    • To register to the Red Hat Customer Portal by using a proxy:

      ---
      - name: Register using proxy
        hosts: managed-node-01.example.com
        vars_files:
          - vault.yml
        roles:
          - role: rhel-system-roles.rhc
        vars:
          rhc_auth:
            login:
              username: "{{ username }}"
              password: "{{ password }}"
          rhc_proxy:
            hostname: proxy.example.com
            port: 3128
            username: "{{ proxy_username }}"
            password: "{{ proxy_password }}"
    • 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:
          - vault.yml
        vars:
          rhc_auth:
            login:
              username: "{{ username }}"
              password: "{{ password }}"
          rhc_proxy: {"state":"absent"}
        roles:
          - role: rhel-system-roles.rhc
  3. Validate the playbook syntax:

    $ ansible-playbook --syntax-check --ask-vault-pass ~/playbook.yml

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

  4. Run the playbook:

    $ ansible-playbook --ask-vault-pass ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.rhc/README.md file
  • /usr/share/doc/rhel-system-roles/rhc/ directory
  • Ansible Vault

23.8. Disabling auto updates of Insights rules by using the rhc RHEL 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

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault:

      $ ansible-vault create vault.yml
      New Vault password: <password>
      Confirm New Vault password: <vault_password>
    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format:

      username: <username>
      password: <password>
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.
  2. Create a playbook file, for example ~/playbook.yml, with the following content:

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

    $ ansible-playbook --syntax-check --ask-vault-pass ~/playbook.yml

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

  4. Run the playbook:

    $ ansible-playbook --ask-vault-pass ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.rhc/README.md file
  • /usr/share/doc/rhel-system-roles/rhc/ directory
  • Ansible Vault

23.9. 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 RHEL 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.
  • You have Insights remediations enabled.
  • You have registered the system.

Procedure

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

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

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

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

23.10. Configuring Insights tags by using the rhc RHEL system role

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

Prerequisites

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault:

      $ ansible-vault create vault.yml
      New Vault password: <password>
      Confirm New Vault password: <vault_password>
    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format:

      username: <username>
      password: <password>
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.
  2. Create a playbook file, for example ~/playbook.yml, with the following content:

    ---
    - name: Creating tags
      hosts: managed-node-01.example.com
      vars_files:
        - vault.yml
      roles:
        - role: rhel-system-roles.rhc
      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
  3. Validate the playbook syntax:

    $ ansible-playbook --syntax-check --ask-vault-pass ~/playbook.yml

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

  4. Run the playbook:

    $ ansible-playbook --ask-vault-pass ~/playbook.yml

Additional resources

23.11. Unregistering a system by using the rhc RHEL system role

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

Prerequisites

Procedure

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

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

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

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

Chapter 24. Configuring SELinux by using the RHEL system role

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

24.1. Introduction to the selinux RHEL 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. You can perform the following actions by using the selinux RHEL system role:

  • 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 /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.

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.selinux/README.md file
  • /usr/share/doc/rhel-system-roles/selinux/ directory

24.2. Using the selinux RHEL system role to apply SELinux settings on multiple systems

With the selinux RHEL system role, you can prepare and apply an Ansible playbook with your verified SELinux settings.

Prerequisites

Procedure

  1. Prepare your playbook. You can either start from 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. Validate the playbook syntax:

    # ansible-playbook <my-selinux-playbook.yml> --syntax-check

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

  5. Run your playbook:

    # ansible-playbook <my-selinux-playbook.yml>

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.selinux/README.md file
  • /usr/share/doc/rhel-system-roles/selinux/ directory
  • SELinux hardening with Ansible Knowledgebase article

24.3. Managing ports by using the selinux RHEL system role

You can automate managing port access in SELinux consistently across multiple systems by using the selinux RHEL system role. This might be useful, for example, when configuring an Apache HTTP server to listen on a different port. You can do this by creating a playbook with the selinux RHEL system role that assigns the http_port_t SELinux type to a specific port number. After you run the playbook on the managed nodes, specific services defined in the SELinux policy can access this port.

You can automate managing port access in SELinux either by using the seport module, which is quicker than using the entire role, or by using the selinux RHEL system role, which is more useful when you also make other changes in SELinux configuration. The methods are equivalent, in fact the selinux RHEL system role uses the seport module when configuring ports. Each of the methods has the same effect as entering the command semanage port -a -t http_port_t -p tcp <port_number> on the managed 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.
  • Optional: To verify port status by using the semanage command, the policycoreutils-python-utils package must be installed.

Procedure

  • To configure just the port number without making other changes, use the seport module:

    - name: Allow Apache to listen on tcp port <port_number>
      community.general.seport:
        ports: <port_number>
        proto: tcp
        setype: http_port_t
        state: present

    Replace <port_number> with the port number to which you want to assign the http_port_t type.

  • For more complex configuration of the managed nodes that involves other customizations of SELinux, use the selinux RHEL system role. Create a playbook file, for example, ~/playbook.yml, and add the following content:

    ---
    - name: Modify SELinux port mapping example
      hosts: all
      vars:
        # Map tcp port <port_number> to the 'http_port_t' SELinux port type
        selinux_ports:
          - ports: <port_number>
            proto: tcp
            setype: http_port_t
            state: present
    
      tasks:
        - name: Include selinux role
          ansible.builtin.include_role:
            name: rhel-system-roles.selinux

    Replace <port_number> with the port number to which you want to assign the http_port_t type.

Verification

  • Verify that the port is assigned to the http_port_t type:

    # semanage port --list | grep http_port_t
    http_port_t                	tcp  	<port_number>, 80, 81, 443, 488, 8008, 8009, 8443, 9000

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.selinux/README.md file
  • /usr/share/doc/rhel-system-roles/selinux/ directory

Chapter 25. Securing file access by using the RHEL system role

With the fapolicyd System Role, you can prevent execution of unknown code on RHEL by using the Red Hat Ansible Automation Platform.

25.1. Configuring protection against unknown code execution with the fapolicyd RHEL system role

You can use the fapolicyd System Role to prevent execution of unknown code by running an Ansible playbook.

Prerequisites

Procedure

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

    ---
    - name: Preventing execution of unknown code
      hosts: all
      vars:
        fapolicyd_setup_integrity: sha256
        fapolicyd_setup_trust: rpmdb,file
        fapolicyd_add_trusted_file:
          - </usr/bin/my-ls>
          - </opt/third-party/app1>
          - </opt/third-party/app2>
      roles:
        - rhel-system-roles.fapolicyd

    You can further customize the protection by using the following variables of the linux-system-roles.fapolicyd RHEL System Role:

    fapolicyd_setup_integrity
    You can set one of the following types of integrity: none, sha256, and size.
    fapolicyd_setup_trust
    You can set trust file types file,rpmd, and deb.
    fapolicyd_add_trusted_file
    You can list executable files that you trust and that fapolicyd does not prevent from executing.
  2. Validate the playbook syntax:

    # ansible-playbook ~/playbook.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 ~/playbook.yml

Additional resources

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

Chapter 26. Configuring secure communication by using 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 using the Ansible Core package.

26.1. Variables of the sshd RHEL system role

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 ::

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.sshd/README.md file
  • /usr/share/doc/rhel-system-roles/sshd/ directory

26.2. Configuring OpenSSH servers by using the sshd RHEL 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

Procedure

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

    ---
    - name: SSH server configuration
      hosts: managed-node-01.example.com
      tasks:
        - name: Configure sshd to prevent root and password login except from particular subnet
          ansible.builtin.include_role:
            name: rhel-system-roles.sshd
          vars:
            sshd:
              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
  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Verification

  1. Log in to the SSH server:

    $ ssh <username>@<ssh_server>
  2. Verify the contents of the sshd_config file on the SSH server:

    $ cat /etc/ssh/sshd_config.d/00-ansible_system_role.conf
    #
    # Ansible managed
    #
    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@<ssh_server>

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.sshd/README.md file
  • /usr/share/doc/rhel-system-roles/sshd/ directory

26.3. Using the sshd RHEL 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.

You can apply a non-exclusive configuration:

  • In RHEL 8 and earlier by using a configuration snippet.
  • In RHEL 9 and later by using files in a drop-in directory. The default configuration file is already placed in the drop-in directory as /etc/ssh/sshd_config.d/00-ansible_system_role.conf.

Prerequisites

Procedure

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

    • For managed nodes that run RHEL 8 or earlier:

      ---
      - name: Non-exclusive sshd configuration
        hosts: managed-node-01.example.com
        tasks:
          - name: <Configure SSHD to accept some useful environment variables>
            ansible.builtin.include_role:
              name: rhel-system-roles.sshd
            vars:
              sshd_config_namespace: <my-application>
              sshd:
                # Environment variables to accept
                AcceptEnv:
                  LANG
                  LS_COLORS
                  EDITOR
    • For managed nodes that run RHEL 9 or later:

      - name: Non-exclusive sshd configuration
        hosts: managed-node-01.example.com
        tasks:
          - name: <Configure sshd to accept some useful environment variables>
            ansible.builtin.include_role:
              name: rhel-system-roles.sshd
            vars:
              sshd_config_file: /etc/ssh/sshd_config.d/<42-my-application>.conf
              sshd:
                # Environment variables to accept
                AcceptEnv:
                  LANG
                  LS_COLORS
                  EDITOR

      In the sshd_config_file variable, define the .conf file into which the sshd system role writes the configuration options. Use a two-digit prefix, for example 42- to specify the order in which the configuration files will be applied.

  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Verification

  • Verify the configuration on the SSH server:

    • For managed nodes that run RHEL 8 or earlier:

      # cat /etc/ssh/sshd_config.d/42-my-application.conf
      # Ansible managed
      #
      AcceptEnv LANG LS_COLORS EDITOR
    • For managed nodes that run RHEL 9 or later:

      # cat /etc/ssh/sshd_config
      ...
      # 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>

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.sshd/README.md file
  • /usr/share/doc/rhel-system-roles/sshd/ directory

26.4. Overriding the system-wide cryptographic policy on an SSH server by using the sshd RHEL system role

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

Prerequisites

Procedure

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

    - name: Overriding the system-wide cryptographic policy
      hosts: managed-node-01.example.com
      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
    • 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.
    • 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.

    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.

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

  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Verification

  • 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 <ssh_server>
    ...
    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
    ...

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.sshd/README.md file
  • /usr/share/doc/rhel-system-roles/sshd/ directory

26.5. Variables of the ssh RHEL system role

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.

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.ssh/README.md file
  • /usr/share/doc/rhel-system-roles/ssh/ directory

26.6. Configuring OpenSSH clients by using the ssh RHEL 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 in RHEL 8 and later).

Prerequisites

Procedure

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

    ---
    - name: SSH client configuration
      hosts: managed-node-01.example.com
      tasks:
        - name: "Configure ssh clients"
          ansible.builtin.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: server.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 server.example.com host is user1.
    • The example host alias is created, which represents a connection to the server.example.com host the with the user1 user name.
    • X11 forwarding is disabled.
  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Verification

  • Verify that the managed node has the correct configuration by displaying the SSH configuration file:

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

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.ssh/README.md file
  • /usr/share/doc/rhel-system-roles/ssh/ directory

Chapter 27. Managing local storage by using the RHEL system role

To manage LVM and local file systems (FS) by using Ansible, you can use the storage role, which is one of the RHEL system roles available in RHEL 9.

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.

27.1. 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

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.storage/README.md file
  • /usr/share/doc/rhel-system-roles/storage/ directory

27.2. Creating an XFS file system on a block device by using the storage RHEL system role

The example Ansible playbook applies the storage role to create an XFS file system on a block device using the default parameters.

Note

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.

Prerequisites

Procedure

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

    ---
    - hosts: managed-node-01.example.com
      roles:
        - rhel-system-roles.storage
      vars:
        storage_volumes:
          - name: barefs
            type: disk
            disks:
              - sdb
            fs_type: xfs
    • 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 9.
    • To create the file system on an LV, provide the LVM setup under the disks: attribute, including the enclosing volume group. For details, see Managing logical volumes by using the storage RHEL system role.

      Do not provide the path to the LV device.

  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.storage/README.md file
  • /usr/share/doc/rhel-system-roles/storage/ directory

27.3. Persistently mounting a file system by using the storage RHEL system role

The example Ansible applies the storage role to immediately and persistently mount an XFS file system.

Prerequisites

Procedure

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

    ---
    - hosts: managed-node-01.example.com
      roles:
        - rhel-system-roles.storage
      vars:
        storage_volumes:
          - name: barefs
            type: disk
            disks:
              - sdb
            fs_type: xfs
            mount_point: /mnt/data
            mount_user: somebody
            mount_group: somegroup
            mount_mode: 0755
    • 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.
  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.storage/README.md file
  • /usr/share/doc/rhel-system-roles/storage/ directory

27.4. Managing logical volumes by using the storage RHEL system role

The example Ansible playbook applies the storage role to create an LVM logical volume in a volume group.

Prerequisites

Procedure

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

    - hosts: managed-node-01.example.com
      roles:
        - rhel-system-roles.storage
      vars:
        storage_pools:
          - name: myvg
            disks:
              - sda
              - sdb
              - sdc
            volumes:
              - name: mylv
                size: 2G
                fs_type: ext4
                mount_point: /mnt/dat
    • The myvg volume group consists of the following disks: /dev/sda, /dev/sdb, and /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.
  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.storage/README.md file
  • /usr/share/doc/rhel-system-roles/storage/ directory

27.5. Enabling online block discard by using the storage RHEL system role

The example Ansible playbook applies the storage role to mount an XFS file system with online block discard enabled.

Prerequisites

Procedure

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

    ---
    - hosts: managed-node-01.example.com
      roles:
        - rhel-system-roles.storage
      vars:
        storage_volumes:
          - name: barefs
            type: disk
            disks:
              - sdb
            fs_type: xfs
            mount_point: /mnt/data
            mount_options: discard
  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.storage/README.md file
  • /usr/share/doc/rhel-system-roles/storage/ directory

27.6. Creating and mounting an Ext4 file system by using the storage RHEL system role

The example Ansible playbook applies the storage role to create and mount an Ext4 file system.

Prerequisites

Procedure

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

    ---
    - hosts: managed-node-01.example.com
      roles:
        - rhel-system-roles.storage
      vars:
        storage_volumes:
          - name: barefs
            type: disk
            disks:
              - sdb
            fs_type: ext4
            fs_label: label-name
            mount_point: /mnt/data
    • 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.
  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.storage/README.md file
  • /usr/share/doc/rhel-system-roles/storage/ directory

27.7. Creating and mounting an Ext3 file system by using the storage RHEL system role

The example Ansible playbook applies the storage role to create and mount an Ext3 file system.

Prerequisites

Procedure

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

    ---
    - hosts: all
      roles:
        - rhel-system-roles.storage
      vars:
        storage_volumes:
          - name: barefs
            type: disk
            disks:
              - sdb
            fs_type: ext3
            fs_label: label-name
            mount_point: /mnt/data
            mount_user: somebody
            mount_group: somegroup
            mount_mode: 0755
    • 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.
  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.storage/README.md file
  • /usr/share/doc/rhel-system-roles/storage/ directory

27.8. Resizing an existing file system on LVM by 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.

Prerequisites

Procedure

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

    ---
    - name: Create LVM pool over three disks
      hosts: managed-node-01.example.com
      tasks:
        - name: Resize LVM logical volume with file system
          ansible.builtin.include_role:
            name: rhel-system-roles.storage
          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

    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.
  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.storage/README.md file
  • /usr/share/doc/rhel-system-roles/storage/ directory

27.9. Creating a swap volume by 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 by using the default parameters.

Prerequisites

Procedure

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

    ---
    - name: Create a disk device with swap
      hosts: managed-node-01.example.com
      roles:
        - rhel-system-roles.storage
      vars:
        storage_volumes:
          - name: swap_fs
            type: disk
            disks:
              - /dev/sdb
            size: 15 GiB
            fs_type: swap

    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.

  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.storage/README.md file
  • /usr/share/doc/rhel-system-roles/storage/ directory

27.10. Configuring a RAID volume by using the storage RHEL system role

With the storage system role, you can configure a RAID volume on RHEL by 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.

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.

Prerequisites

Procedure

  1. Create a playbook file, for example ~/playbook.yml, 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
          ansible.builtin.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
  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.storage/README.md file
  • /usr/share/doc/rhel-system-roles/storage/ directory

27.11. Configuring an LVM pool with RAID by using the storage RHEL system role

With the storage system role, you can configure an LVM pool with RAID on RHEL by 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

Procedure

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

    ---
    - name: Configure LVM pool with RAID
      hosts: managed-node-01.example.com
      roles:
        - rhel-system-roles.storage
      vars:
        storage_safe_mode: false
        storage_pools:
          - name: my_pool
            type: lvm
            disks: [sdh, sdi]
            raid_level: raid1
            volumes:
              - name: my_volume
                size: "1 GiB"
                mount_point: "/mnt/app/shared"
                fs_type: xfs
                state: present

    To create an LVM pool with RAID, you must specify the RAID type by using the raid_level parameter.

  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.storage/README.md file
  • /usr/share/doc/rhel-system-roles/storage/ directory
  • Managing RAID

27.12. Configuring a stripe size for RAID LVM volumes by using the storage RHEL system role

With the storage system role, you can configure a stripe size for RAID LVM volumes on RHEL by 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

Procedure

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

    ---
    - name: Configure stripe size for RAID LVM volumes
      hosts: managed-node-01.example.com
      roles:
        - rhel-system-roles.storage
      vars:
        storage_safe_mode: false
        storage_pools:
          - name: my_pool
            type: lvm
            disks: [sdh, sdi]
            volumes:
              - name: my_volume
                size: "1 GiB"
                mount_point: "/mnt/app/shared"
                fs_type: xfs
                raid_level: raid1
                raid_stripe_size: "256 KiB"
                state: present
  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.storage/README.md file
  • /usr/share/doc/rhel-system-roles/storage/ directory
  • Managing RAID

27.13. Compressing and deduplicating a VDO volume on LVM by 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) by using Virtual Data Optimizer (VDO).

Note

Because of the storage system role use of LVM VDO, only one volume per pool can use the compression and deduplication.

Prerequisites

Procedure

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

    - name: Create LVM VDO volume under volume group 'myvg'
      hosts: managed-node-01.example.com
      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.
  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.storage/README.md file
  • /usr/share/doc/rhel-system-roles/storage/ directory

27.14. Creating a LUKS2 encrypted volume by 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

Procedure

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

    ---
    - name: Create and configure a volume encrypted with LUKS
      hosts: managed-node-01.example.com
      roles:
        - rhel-system-roles.storage
      vars:
        storage_volumes:
          - name: barefs
            type: disk
            disks:
             - sdb
            fs_type: xfs
            fs_label: label-name
            mount_point: /mnt/data
            encryption: true
            encryption_password: <password>

    You can also add other encryption parameters, such as encryption_key, encryption_cipher, encryption_key_size, and encryption_luks, to the playbook file.

  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/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]
    ...

Additional resources

27.15. Expressing pool volume sizes as percentage by 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.

Prerequisites

Procedure

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

    ---
    - name: Express volume sizes as a percentage of the pool's total size
      hosts: managed-node-01.example.com
      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%. Alternatively, 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.

  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.storage/README.md file
  • /usr/share/doc/rhel-system-roles/storage/ directory

Chapter 28. Managing systemd units by using the RHEL system role

With the systemd RHEL 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 RHEL 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.

28.1. Deploying and starting a systemd unit by using the systemd RHEL 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 RHEL system role variables in a playbook to define which unit files systemd manages, starts, and enables.

Prerequisites

Procedure

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

    ---
    - name: Deploy and start systemd unit
      hosts: managed-node-01.example.com
      roles:
        - rhel-system-roles.systemd
      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
  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.systemd/README.md file
  • /usr/share/doc/rhel-system-roles/systemd/ directory

Chapter 29. Configuring time synchronization by using the 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.

29.1. 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.

  • /usr/share/ansible/roles/rhel-system-roles.timesync/README.md file
  • /usr/share/doc/rhel-system-roles/timesync/ directory

29.2. Applying the timesync RHEL 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

Procedure

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

    ---
    - name: Manage time synchronization
      hosts: managed-node-01.example.com
      roles:
        - rhel-system-roles.timesync
      vars:
        timesync_ntp_servers:
          - hostname: 2.rhel.pool.ntp.org
            pool: yes
            iburst: yes
  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.timesync/README.md file
  • /usr/share/doc/rhel-system-roles/timesync/ directory

29.3. Applying the timesync RHEL 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 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 chrony NTP provider version is 4.0 or later.

Procedure

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

    ---
    - name: Enable Network Time Security on NTP clients
      hosts: managed-node-01.example.com
      roles:
        - rhel-system-roles.timesync
      vars:
        timesync_ntp_servers:
          - hostname: ptbtime1.ptb.de
            iburst: yes
            nts: yes

    ptbtime1.ptb.de is an example of a public server. You may want to use a different public server or your own server.

  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/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

  • /usr/share/ansible/roles/rhel-system-roles.timesync/README.md file
  • /usr/share/doc/rhel-system-roles/timesync/ directory

Chapter 30. Configuring a system for session recording by using the RHEL system role

With the tlog RHEL system role, you can configure a system for terminal session recording on RHEL by using Red Hat Ansible Automation Platform.

30.1. The tlog RHEL 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

  • /usr/share/ansible/roles/rhel-system-roles.ha_cluster/README.md file
  • /usr/share/doc/rhel-system-roles/ha_cluster/ directory

30.2. Components and parameters of the tlog RHEL system role

The Session Recording solution has the following components:

  • The tlog utility
  • System Security Services Daemon (SSSD)
  • Optional: The web console interface

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.ha_cluster/README.md file
  • /usr/share/doc/rhel-system-roles/ha_cluster/ directory

30.3. 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.

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.

Prerequisites

Procedure

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

    ---
    - name: Deploy session recording
      hosts: managed-node-01.example.com
      roles:
        - rhel-system-roles.tlog
      vars:
        tlog_scope_sssd: some
        tlog_users_sssd:
          - recorded-user
    tlog_scope_sssd
    The some value specifies you want to record only certain users and groups, not all or none.
    tlog_users_sssd
    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. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Verification

  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.

  3. Log in as a user whose session will be recorded.
  4. Play back a recorded session.

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.tlog/README.md file
  • /usr/share/doc/rhel-system-roles/tlog/ directory

30.4. 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.

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.

Prerequisites

Procedure

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

    ---
    - name: Deploy session recording excluding users and groups
      hosts: managed-node-01.example.com
      roles:
        - rhel-system-roles.tlog
      vars:
        tlog_scope_sssd: all
        tlog_exclude_users_sssd:
          - jeff
          - james
        tlog_exclude_groups_sssd:
          - admins
    tlog_scope_sssd
    The value all specifies that you want to record all users and groups.
    tlog_exclude_users_sssd
    Specifies the user names of the users you want to exclude from the session recording.
    tlog_exclude_groups_sssd
    Specifies the group you want to exclude from the session recording.
  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Verification

  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.

  3. Log in as a user whose session will be recorded.
  4. Play back a recorded session.

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.tlog/README.md file
  • /usr/share/doc/rhel-system-roles/tlog/ directory

Chapter 31. Configuring VPN connections with IPsec by using the 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.

31.1. Creating a host-to-host VPN with IPsec by using the vpn RHEL 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 configures all managed nodes listed in an inventory file.

Prerequisites

Procedure

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

    - name: Host to host VPN
      hosts: managed-node-01.example.com, managed-node-02.example.com
      roles:
        - rhel-system-roles.vpn
      vars:
        vpn_connections:
          - hosts:
              managed-node-01.example.com:
              managed-node-02.example.com:
        vpn_manage_firewall: true
        vpn_manage_selinux: true

    This playbook configures the connection managed-node-01.example.com-to-managed-node-02.example.com by 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.

    To configure connections from managed hosts to external hosts that are not listed in the inventory file, add the following section to the vpn_connections list of hosts:

        vpn_connections:
          - hosts:
              managed-node-01.example.com:
              <external_node>:
                hostname: <IP_address_or_hostname>

    This configures one additional connection: managed-node-01.example.com-to-<external_node>

    Note

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

  2. 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-node-01.example.com, managed-node-02.example.com
      roles:
        - rhel-system-roles.vpn
      vars:
        vpn_connections:
          - name: control_plane_vpn
            hosts:
              managed-node-01.example.com:
                hostname: 192.0.2.0 # IP for the control plane
              managed-node-02.example.com:
                hostname: 192.0.2.1
          - name: data_plane_vpn
            hosts:
              managed-node-01.example.com:
                hostname: 10.0.0.1 # IP for the data plane
              managed-node-02.example.com:
                hostname: 10.0.0.2
  3. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  4. Run the playbook:

    $ ansible-playbook ~/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.

  2. On the managed nodes, confirm that the connection is successfully started:

    # ipsec trafficstatus | grep <connection_name>
  3. Optional: If a connection does not successfully load, manually add the connection by entering the following command. This provides more specific information indicating why the connection failed to establish:

    # ipsec auto --add <connection_name>
    Note

    Any errors that may occur during the process of loading and starting the connection are reported in the /var/log/pluto.log file. Because these logs are hard to parse, manually add the connection to obtain log messages from the standard output instead.

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.vpn/README.md file
  • /usr/share/doc/rhel-system-roles/vpn/ directory

31.2. Creating an opportunistic mesh VPN connection with IPsec by using the vpn RHEL 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.

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 IPsec Network Security Services (NSS) crypto library in the /etc/ipsec.d/ directory contains the necessary certificates.

Procedure

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

    - name: Mesh VPN
      hosts: managed-node-01.example.com, managed-node-02.example.com, managed-node-03.example.com
      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

    Authentication with certificates is configured by defining the auth_method: cert parameter in the playbook. By default, the node name is used as the certificate nickname. In this example, this is managed-node-01.example.com. You can define different certificate names by using the cert_name attribute in your inventory.

    In this 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.

    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. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

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

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.vpn/README.md file
  • /usr/share/doc/rhel-system-roles/vpn/ directory

Legal Notice

Copyright © 2024 Red Hat, Inc.
The text of and illustrations in this document are licensed by Red Hat under a Creative Commons Attribution–Share Alike 3.0 Unported license ("CC-BY-SA"). An explanation of CC-BY-SA is available at http://creativecommons.org/licenses/by-sa/3.0/. In accordance with CC-BY-SA, if you distribute this document or an adaptation of it, you must provide the URL for the original version.
Red Hat, as the licensor of this document, waives the right to enforce, and agrees not to assert, Section 4d of CC-BY-SA to the fullest extent permitted by applicable law.
Red Hat, Red Hat Enterprise Linux, the Shadowman logo, the Red Hat logo, JBoss, OpenShift, Fedora, the Infinity logo, and RHCE are trademarks of Red Hat, Inc., registered in the United States and other countries.
Linux® is the registered trademark of Linus Torvalds in the United States and other countries.
Java® is a registered trademark of Oracle and/or its affiliates.
XFS® is a trademark of Silicon Graphics International Corp. or its subsidiaries in the United States and/or other countries.
MySQL® is a registered trademark of MySQL AB in the United States, the European Union and other countries.
Node.js® is an official trademark of Joyent. Red Hat is not formally related to or endorsed by the official Joyent Node.js open source or commercial project.
The OpenStack® Word Mark and OpenStack logo are either registered trademarks/service marks or trademarks/service marks of the OpenStack Foundation, in the United States and other countries and are used with the OpenStack Foundation's permission. We are not affiliated with, endorsed or sponsored by the OpenStack Foundation, or the OpenStack community.
All other trademarks are the property of their respective owners.