- name: Detect syslog
  stat:
    path: /var/log/syslog
  register: syslog

- name: Detect journalctl
  shell: command -V journalctl
  ignore_errors: yes
  changed_when: no
  register: journalctl

- block:
    - name: Skip tests if logs were not found.
      debug:
        msg: Did not find /var/log/syslog or journalctl. Tests will be skipped.
    - meta: end_play
  when: journalctl is failed and not syslog.stat.exists

- name: Generate random numbers for unique log entries
  set_fact:
    good_number: "{{ 999999999999 | random }}"
    bad_number: "{{ 999999999999 | random }}"

- name: Generate expected log entry messages
  set_fact:
    good_message: 'My number is: ({{ good_number }})'
    bad_message: 'My number is: ({{ bad_number }})'

- name: Generate log message search patterns
  set_fact:
    # these search patterns are designed to avoid matching themselves
    good_search: '{{ good_message.replace(":", "[:]") }}'
    bad_search: '{{ bad_message.replace(":", "[:]") }}'

- name: Generate grep command
  set_fact:
    grep_command: "grep -e '{{ good_search }}' -e '{{ bad_search }}'"

- name: Run a module that logs without no_log
  module_that_logs:
    number: "{{ good_number }}"

- name: Run a module that logs with no_log
  module_that_logs:
    number: "{{ bad_number }}"
  no_log: yes

- name: Search for expected log messages
  # if this fails the tests are probably running on a system which stores logs elsewhere
  shell: "({{ grep_command }} /var/log/syslog) || (journalctl | {{ grep_command }})"
  changed_when: no
  register: grep

- name: Verify the correct log messages were found
  assert:
    that:
      # if the good message is not found then the cause is likely one of:
      # 1) the remote system does not write user.info messages to the logs
      # 2) the AnsibleModule.log method is not working
      - good_message in grep.stdout
      - bad_message not in grep.stdout