at: add support for AIX

[dberg1]

SUMMARY

The at module does not work correctly on AIX.
Trying to remove a job fails with a syntax error.
Setting the unique attribute to yes also fails.
AIX uses -lv options to cat a job (instead of -c for Linux) and -r to remove a job.
Linux supports both -r and -d, so use -r since it is what POSIX says.
See https://www.ibm.com/support/knowledgecenter/ssw_aix_72/a_commands/at.html and https://pubs.opengroup.org/onlinepubs/9699919799/utilities/at.html
Other systems like SunOS or the BSDs also appear to use -r to remove a job.

ISSUE TYPE

• Bugfix Pull Request

COMPONENT NAME

at

ADDITIONAL INFORMATION

To recreate the issue, use the following playbook:

- hosts: aix
  gather_facts: no
  tasks:
  - at:
      command: "ls -d / > /dev/null"
      state: absent

This fails with:

fatal: [aix-host1]: FAILED! => {
    "changed": false,
    "cmd": "/usr/bin/at -c root.1599830992c0.a",
    "invocation": {
        "module_args": {
            "command": "ls -d / > /dev/null",
            "count": null,
            "script_file": null,
            "state": "absent",
            "unique": false,
            "units": null
        }
    },
    "msg": "at: syntax error",
    "rc": 1,
    "stderr": "at: syntax error\n",
    "stderr_lines": [
        "at: syntax error"
    ],
    "stdout": "",
    "stdout_lines": []
}

[maxamillion]

I don't have a way to test this myself because I don't have access to an AIX system but the code change looks good, thank you for the contribution!

[czi]

Thank you for this. Issue 62153 / bugfix 62154 got ignored by Redhat and closed with the move to ansible-posix. I'm glad to see this finally merged!