https://stackoverflow.com/questions/53385430/monitor-recent-entries-of-a-log-file-with-ansible

• name: HUP certain_process
  command: "pkill -HUP certain_process"

• name: Get the content of the last line in logfile
  shell: tail -1 logfile
  register: tail_output

• name: Waits until process HUP finishes
  wait_for:
  path: '{{tail_output.stdout_lines}}'
  search_regex: "Configuration data reloaded"
  delay: 20
  timeout: 280
  register: wait
  ignore_errors: True

• name: Fail if HUP failed
  fail: msg="App HUP failed"
  when: wait|failed
  and the output:

TASK [HUP certain_process] **************************************************************
Tuesday 20 November 2018 01:14:18 +0000 (0:00:05.575) 0:00:20.148 ******
changed: [host1]

TASK [Get the contents of the last line in logfile] ***************
Tuesday 20 November 2018 01:14:23 +0000 (0:00:05.413) 0:00:25.561 ******
changed: [host1]

TASK [Waits until process HUP finishes] ****************************************
Tuesday 20 November 2018 01:14:27 +0000 (0:00:04.067) 0:00:29.629 ******
fatal: [host1]: FAILED! => {"changed": false, "elapsed": 280, "failed": true, "msg": "Timeout when waiting for search string Configuration data reloaded in ['Nov 20 01:44:28 host1 SYS(15) HUP signal detected: reloading configuration data...']"}
...ignoring

TASK [Fail if hupped failed] ***************************************************
Tuesday 20 November 2018 01:19:13 +0000 (0:04:45.737) 0:05:15.366 ******
fatal: [host1]: FAILED! => {"changed": false, "failed": true, "msg": "App HUP failed"}
to retry, use: --limit @/export/home/carlos/project/policyUpdate.retry