4.5. Optional: Adding hooks to perform Ansible tasks on RHEL machines

Procedure

1. After you design the hook, create a YAML file that defines the Ansible tasks for it. This file must be a set of tasks and cannot be a playbook, as shown in the following example:

   ---
   # Trivial example forcing an operator to acknowledge the start of an upgrade
   # file=/home/user/openshift-ansible/hooks/pre_compute.yml
   
   - name: note the start of a compute machine update
     debug:
         msg: "Compute machine upgrade of {{ inventory_hostname }} is about to start"
   
   - name: require the user agree to start an upgrade
     pause:
         prompt: "Press Enter to start the compute machine update"

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2. Modify the hosts Ansible inventory file to specify the hook files. The hook files are specified as parameter values in the [all:vars] section, as shown:

   Example hook definitions in an inventory file

   [all:vars]
   openshift_node_pre_upgrade_hook=/home/user/openshift-ansible/hooks/pre_node.yml
   openshift_node_post_upgrade_hook=/home/user/openshift-ansible/hooks/post_node.yml

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   To avoid ambiguity in the paths to the hook, use absolute paths instead of a relative paths in their definitions.