Use Ansible to perform a rolling restart of an application service across an inventory group with serial batching and pre/post health checks

Steps

1. Set serial: "25%" (or a list like [1, 5, "100%"]) in the play header so Ansible processes hosts in batches rather than all at once
2. Add a pre_tasks block that checks service health before the rolling action: use uri module to hit the health endpoint and register the result, failing the play if status != 200
3. Use the systemd or service module to restart the target service: name: myapp state: restarted
4. Add a post_tasks block that waits for the service to return healthy: use wait_for_connection or uri with retries and delay, then assert the expected response
5. Set max_fail_percentage: 0 in the play to abort the entire rolling restart if any host in a batch fails its health check, preventing a bad restart from propagating
6. Run with ansible-playbook rolling_restart.yml -i inventory/prod --check first for a dry run, then without --check for the live execution