Chapter 28. Managing hosts using Ansible playbooks

Ansible is an automation tool used to configure systems, deploy software, and perform rolling updates. Ansible includes support for Identity Management (IdM), and you can use Ansible modules to automate host management.

This chapter describes the following operations performed when managing hosts and host entries using Ansible playbooks:

28.1. Ensuring the presence of an IdM host entry with FQDN using Ansible playbooks

This section describes ensuring the presence of host entries in Identity Management (IdM) using Ansible playbooks. The host entries are only defined by their fully-qualified domain names (FQDNs).

Specifying the FQDN name of the host is enough if at least one of the following conditions applies:

  • The IdM server is not configured to manage DNS.
  • The host does not have a static IP address or the IP address is not known at the time the host is configured. Adding a host defined only by an FQDN essentially creates a placeholder entry in the IdM DNS service. For example, laptops may be preconfigured as IdM clients, but they do not have IP addresses at the time they are configured. When the DNS service dynamically updates its records, the host’s current IP address is detected and its DNS record is updated.
Note

Without Ansible, host entries are created in IdM using the ipa host-add command. The result of adding a host to IdM is the state of the host being present in IdM. Because of the Ansible reliance on idempotence, to add a host to IdM using Ansible, you must create a playbook in which you define the state of the host as present: state: present.

Prerequisites

  • You know the IdM administrator password.
  • The ansible-freeipa package is installed on the Ansible controller.

Procedure

  1. Create an inventory file, for example inventory.file, and define ipaserver in it:

    [ipaserver]
    server.idm.example.com
  2. Create an Ansible playbook file with the FQDN of the host whose presence in IdM you want to ensure. To simplify this step, you can copy and modify the example in the /usr/share/doc/ansible-freeipa/playbooks/host/add-host.yml file:

    ---
    - name: Host present
      hosts: ipaserver
      become: true
    
      tasks:
      - name: Host host01.idm.example.com present
        ipahost:
          ipaadmin_password: Secret123
          name: host01.idm.example.com
          state: present
          force: yes
  3. Run the playbook:

    $ ansible-playbook -v -i path_to_inventory_directory/inventory.file path_to_playbooks_directory/ensure-host-is-present.yml
Note

The procedure results in a host entry in the IdM LDAP server being created but not in enrolling the host into the IdM Kerberos realm. For that, you must deploy the host as an IdM client. For details, see Installing an Identity Management client using an Ansible playbook.

Verification steps

  1. Log in to your IdM server as admin:

    $ ssh admin@server.idm.example.com
    Password:
  2. Enter the ipa host-show command and specify the name of the host:

    $ ipa host-show host01.idm.example.com
      Host name: host01.idm.example.com
      Principal name: host/host01.idm.example.com@IDM.EXAMPLE.COM
      Principal alias: host/host01.idm.example.com@IDM.EXAMPLE.COM
      Password: False
      Keytab: False
      Managed by: host01.idm.example.com

The output confirms that host01.idm.example.com exists in IdM.

28.2. Ensuring the presence of an IdM host entry with DNS information using Ansible playbooks

This section describes ensuring the presence of host entries in Identity Management (IdM) using Ansible playbooks. The host entries are defined by their fully-qualified domain names (FQDNs) and their IP addresses.

Note

Without Ansible, host entries are created in IdM using the ipa host-add command. The result of adding a host to IdM is the state of the host being present in IdM. Because of the Ansible reliance on idempotence, to add a host to IdM using Ansible, you must create a playbook in which you define the state of the host as present: state: present.

Prerequisites

  • You know the IdM administrator password.
  • The ansible-freeipa package is installed on the Ansible controller.

Procedure

  1. Create an inventory file, for example inventory.file, and define ipaserver in it:

    [ipaserver]
    server.idm.example.com
  2. Create an Ansible playbook file with the fully-qualified domain name (FQDN) of the host whose presence in IdM you want to ensure. In addition, if the IdM server is configured to manage DNS and you know the IP address of the host, specify a value for the ip_address parameter. The IP address is necessary for the host to exist in the DNS resource records. To simplify this step, you can copy and modify the example in the /usr/share/doc/ansible-freeipa/playbooks/host/host-present.yml file. You can also include other, additional information:

    ---
    - name: Host present
      hosts: ipaserver
      become: true
    
      tasks:
      - name: Ensure host01.idm.example.com is present
        ipahost:
          ipaadmin_password: ADMPassword123
          name: host01.idm.example.com
          description: Example host
          ip_address: 192.168.0.123
          locality: Lab
          ns_host_location: Lab
          ns_os_version: CentOS 7
          ns_hardware_platform: Lenovo T61
          mac_address:
          - "08:00:27:E3:B1:2D"
          - "52:54:00:BD:97:1E"
          state: present
  3. Run the playbook:

    $ ansible-playbook -v -i path_to_inventory_directory/inventory.file path_to_playbooks_directory/ensure-host-is-present.yml
Note

The procedure results in a host entry in the IdM LDAP server being created but not in enrolling the host into the IdM Kerberos realm. For that, you must deploy the host as an IdM client. For details, see Installing an Identity Management client using an Ansible playbook.

Verification steps

  1. Log in to your IdM server as admin:

    $ ssh admin@server.idm.example.com
    Password:
  2. Enter the ipa host-show command and specify the name of the host:

    $ ipa host-show host01.idm.example.com
      Host name: host01.idm.example.com
      Description: Example host
      Locality: Lab
      Location: Lab
      Platform: Lenovo T61
      Operating system: CentOS 7
      Principal name: host/host01.idm.example.com@IDM.EXAMPLE.COM
      Principal alias: host/host01.idm.example.com@IDM.EXAMPLE.COM
      MAC address: 08:00:27:E3:B1:2D, 52:54:00:BD:97:1E
      Password: False
      Keytab: False
      Managed by: host01.idm.example.com

The output confirms host01.idm.example.com exists in IdM.

28.3. Ensuring the presence of multiple IdM host entries with random passwords using Ansible playbooks

The ipahost module allows the system administrator to ensure the presence or absence of multiple host entries in IdM using just one Ansible task. This section describes how to ensure the presence of multiple host entries that are only defined by their fully-qualified domain names (FQDNs). Running the Ansible playbook generates random passwords for the hosts.

Note

Without Ansible, host entries are created in IdM using the ipa host-add command. The result of adding a host to IdM is the state of the host being present in IdM. Because of the Ansible reliance on idempotence, to add a host to IdM using Ansible, you must create a playbook in which you define the state of the host as present: state: present.

Prerequisites

  • You know the IdM administrator password.
  • The ansible-freeipa package is installed on the Ansible controller.

Procedure

  1. Create an inventory file, for example inventory.file, and define ipaserver in it:

    [ipaserver]
    server.idm.example.com
  2. Create an Ansible playbook file with the fully-qualified domain name (FQDN) of the hosts whose presence in IdM you want to ensure. To make the Ansible playbook generate a random password for each host even when the host already exists in IdM and update_password is limited to on_create, add the random: yes and force: yes options. To simplify this step, you can copy and modify the example from the /usr/share/doc/ansible-freeipa/README-host.md Markdown file:

    ---
    - name: Ensure hosts with random password
      hosts: ipaserver
      become: true
    
      tasks:
      - name: Hosts host01.idm.example.com and host02.idm.example.com present with random passwords
        ipahost:
          ipaadmin_password: MyPassword123
          hosts:
          - name: host01.idm.example.com
            random: yes
            force: yes
          - name: host02.idm.example.com
            random: yes
            force: yes
        register: ipahost
  3. Run the playbook:

    $ ansible-playbook -v -i path_to_inventory_directory/inventory.file path_to_playbooks_directory/ensure-hosts-are-present.yml
    [...]
    TASK [Hosts host01.idm.example.com and host02.idm.example.com present with random passwords]
    changed: [r8server.idm.example.com] => {"changed": true, "host": {"host01.idm.example.com": {"randompassword": "0HoIRvjUdH0Ycbf6uYdWTxH"}, "host02.idm.example.com": {"randompassword": "5VdLgrf3wvojmACdHC3uA3s"}}}

Verification steps

  1. Log in to your IdM server as admin:

    $ ssh admin@server.idm.example.com
    Password:
  2. Enter the ipa host-show command and specify the name of one of the hosts:

    $ ipa host-show host01.idm.example.com
      Host name: host01.idm.example.com
      Password: True
      Keytab: False
      Managed by: host01.idm.example.com

The output confirms host01.idm.example.com exists in IdM with a random password.

28.4. Ensuring the presence of an IdM host entry with multiple IP addresses using Ansible playbooks

This section describes how to ensure the presence of a host entry in Identity Management (IdM) using Ansible playbooks. The host entry is defined by its fully-qualified domain name (FQDN) and its multiple IP addresses.

Note

In contrast to the ipa host utility, the Ansible ipahost module can ensure the presence or absence of several IPv4 and IPv6 addresses for a host. The ipa host-mod command cannot handle IP addresses.

Prerequisites

  • You know the IdM administrator password.
  • The ansible-freeipa package is installed on the Ansible controller.

Procedure

  1. Create an inventory file, for example inventory.file, and define ipaserver in it:

    [ipaserver]
    server.idm.example.com
  2. Create an Ansible playbook file. Specify, as the name of the ipahost variable, the fully-qualified domain name (FQDN) of the host whose presence in IdM you want to ensure. Specify each of the multiple IPv4 and IPv6 ip_address values on a separate line by using the - ip_address syntax. To simplify this step, you can copy and modify the example in the /usr/share/doc/ansible-freeipa/playbooks/host/host-member-ipaddresses-present.yml file. You can also include additional information:

    ---
    - name: Host member IP addresses present
      hosts: ipaserver
      become: true
    
      tasks:
      - name: Ensure host101.example.com IP addresses present
        ipahost:
          ipaadmin_password: Secret123
          name: host01.idm.example.com
          ip_address:
          - 192.168.0.123
          - fe80::20c:29ff:fe02:a1b3
          - 192.168.0.124
          - fe80::20c:29ff:fe02:a1b4
          force: yes
  3. Run the playbook:

    $ ansible-playbook -v -i path_to_inventory_directory/inventory.file path_to_playbooks_directory/ensure-host-with-multiple-IP-addreses-is-present.yml
Note

The procedure creates a host entry in the IdM LDAP server but does not enroll the host into the IdM Kerberos realm. For that, you must deploy the host as an IdM client. For details, see Installing an Identity Management client using an Ansible playbook.

Verification steps

  1. Log in to your IdM server as admin:

    $ ssh admin@server.idm.example.com
    Password:
  2. Enter the ipa host-show command and specify the name of the host:

    $ ipa host-show host01.idm.example.com
      Principal name: host/host01.idm.example.com@IDM.EXAMPLE.COM
      Principal alias: host/host01.idm.example.com@IDM.EXAMPLE.COM
      Password: False
      Keytab: False
      Managed by: host01.idm.example.com

    The output confirms that host01.idm.example.com exists in IdM.

  3. To verify that the multiple IP addresses of the host exist in the IdM DNS records, enter the ipa dnsrecord-show command and specify the following information:

    • The name of the IdM domain
    • The name of the host

      $ ipa dnsrecord-show idm.example.com host01
      [...]
        Record name: host01
        A record: 192.168.0.123, 192.168.0.124
        AAAA record: fe80::20c:29ff:fe02:a1b3, fe80::20c:29ff:fe02:a1b4

    The output confirms that all the IPv4 and IPv6 addresses specified in the playbook are correctly associated with the host01.idm.example.com host entry.

28.5. Ensuring the absence of an IdM host entry using Ansible playbooks

This section describes how to ensure the absence of host entries in Identity Management (IdM) using Ansible playbooks.

Prerequisites

  • IdM administrator credentials

Procedure

  1. Create an inventory file, for example inventory.file, and define ipaserver in it:

    [ipaserver]
    server.idm.example.com
  2. Create an Ansible playbook file with the fully-qualified domain name (FQDN) of the host whose absence from IdM you want to ensure. If your IdM domain has integrated DNS, use the updatedns: yes option to remove the associated records of any kind for the host from the DNS.

    To simplify this step, you can copy and modify the example in the /usr/share/doc/ansible-freeipa/playbooks/host/delete-host.yml file:

    ---
    - name: Host absent
      hosts: ipaserver
      become: true
    
      tasks:
      - name: Host host01.idm.example.com absent
        ipahost:
          ipaadmin_password: MyPassword123
          name: host01.idm.example.com
          updatedns: yes
          state: absent
  3. Run the playbook:

    $ ansible-playbook -v -i path_to_inventory_directory/inventory.file path_to_playbooks_directory/ensure-host-absent.yml
Note

The procedure results in:

  • The host not being present in the IdM Kerberos realm.
  • The host entry not being present in the IdM LDAP server.

To remove the specific IdM configuration of system services, such as System Security Services Daemon (SSSD), from the client host itself, you must run the ipa-client-install --uninstall command on the client. For details, see Uninstalling an IdM client.

Verification steps

  1. Log into ipaserver as admin:

    $ ssh admin@server.idm.example.com
    Password:
    [admin@server /]$
  2. Display information about host01.idm.example.com:

    $ ipa host-show host01.idm.example.com
    ipa: ERROR: host01.idm.example.com: host not found

The output confirms that the host does not exist in IdM.

Additional resources

  • You can see the definitions of the ipahost variables as well as sample Ansible playbooks for ensuring the presence, absence, and disablement of hosts in the /usr/share/doc/ansible-freeipa/README-host.md Markdown file.
  • Additional playbooks are in the /usr/share/doc/ansible-freeipa/playbooks/host directory.