Run fails on new system

[rjhenry]

Looks like the conditional postfix_exporter_version_check.stdout is not defined is never true; on a system with no such binary, I get the following value for postfix_exporter_version_check:

    "postfix_exporter_version_check": {
        "changed": false,
        "cmd": "/usr/local/bin/postfix_exporter --version",
        "failed": false,
        "failed_when_result": false,
        "msg": "[Errno 2] No such file or directory: b'/usr/local/bin/postfix_exporter'",
        "rc": 2,
        "stderr": "",
        "stderr_lines": [],
        "stdout": "",
        "stdout_lines": []
    }

On a host where this is installed, the --version flag doesn't appear to work anyway:

$ /usr/local/bin/postfix_exporter --version
postfix_exporter: error: unknown long flag '--version', try --help

Can be worked around by removing the conditional, but that then copies the binary every time the role is called.

[github-actions]

Hello! This is your first issue on this project. Please be sure to include all necessary information.

[DanielWeeber]

I've applied a million of changes and bugfixes and also included automatic molecule testing.
Also this is now working for ubuntu and RedHat, including the molecule testing.

ref: 7e8ca78

Please update the role and try again :)

[DanielWeeber]

Regarding version flag I opened an issue kumina/postfix_exporter#91

[rjhenry]

Cheers for your quick response, and apologies for the slow response on my part! Your changes look to have done the trick, many thanks. I hope there's a response for the upstream issue soon!

I'll close this one off - feel free to open an alternative to track the version implementation, or not, as the case may be!