A recap there are 2 main use of Blocks in Ansible. The first write-up can be found at Grouping Tasks with Block in Ansible

1. Apply conditional logic to all the tasks within the block. In such a way, the logic only need to be declared once
2. Apply Error handling especially when recovering from an error condition.

Today, we will deal with Point 2 in this blog entry

According to Ansible Documentation found at https://docs.ansible.com/ansible/latest/playbook_guide/playbooks_blocks.html

Rescue blocks specify tasks to run when an earlier task in a block fails. This approach is similar to exception handling in many programming languages. Ansible only runs rescue blocks after a task returns a ‘failed’ state. Bad task definitions and unreachable hosts will not trigger the rescue block.

Here is my simple example for implementation

- name: Check current Timezone
  command: timedatectl show --property=Timezone --value
  register: timezone_output
  changed_when: false

- name: Configure Timezone to Asia/Singapore
  command: timedatectl set-timezone Asia/Singapore
  when: timezone_output.stdout != "Asia/Singapore"

- name: Install and Configure Chrony Service Block
  block:
    - name: Install Chrony package
      dnf:
        name: chrony
        state: present

    - name: Configure Chrony servers
      lineinfile:
        path: /etc/chrony.conf
        line: "server sg.pool.ntp.org iburst"
        insertafter: '^#.*server 3.centos.pool.ntp.org iburst'
        state: present

    - name: Enable Chrony service
      service:
        name: chronyd
        state: started
        enabled: yes
  rescue:
    - name: Print when Errors
      debug:
        msg: 'Something failed at Chrony Setup'
  when:
    - ansible_os_family == "RedHat"
    - ansible_distribution_major_version == "8"