11.4. Configuring a high availability cluster with fencing and resources

Procedure

1. 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:

      cluster_password: <cluster_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: Create a high availability cluster
     hosts: node1 node2
     vars_files:
       - ~/vault.yml
     tasks:
       - name: Create cluster with fencing and resources
         ansible.builtin.include_role:
           name: redhat.rhel_system_roles.ha_cluster
         vars:
           ha_cluster_cluster_name: my-new-cluster
           ha_cluster_hacluster_password: "{{ cluster_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

   The settings specified in the example playbook include the following:

   ha_cluster_cluster_name: <cluster_name>

   The name of the cluster you are creating.

   ha_cluster_hacluster_password: <password>

   The password of the hacluster user. The hacluster user has full access to a cluster.

   ha_cluster_manage_firewall: true

   A variable that determines whether the ha_cluster RHEL system role manages the firewall.

   ha_cluster_manage_selinux: true

   A variable that determines whether the ha_cluster RHEL system role manages the ports of the firewall high availability service using the selinux RHEL system role.

   ha_cluster_resource_primitives: <cluster_resources>

   A list of resource definitions for the Pacemaker resources configured by the ha_cluster RHEL system role, including fencing

   ha_cluster_resource_groups: <resource_groups>

   A list of resource group definitions configured by the ha_cluster RHEL system role.

   ha_cluster_resource_clones: <resource_clones>

   A list of resource clone definitions configured by the ha_cluster RHEL system role.

   For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.ha_cluster/README.md file on the control node.

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