Add version cli argument

[aerialls]

Proposed changes

Add a new flag version to display the current version. This is useful to check if the exporter needs an update without trying to launch the exporter.

Checklist

Before creating a PR, run through this checklist and mark each as complete.

• I have read the CONTRIBUTING guide
• I have proven my fix is effective or that my feature works
• I have checked that all unit tests pass after adding my changes
• I have ensured the README is up to date
• I have rebased my branch onto master
• I will ensure my PR is targeting the master branch and pulling from my branch on my own fork

[lucacome]

Hi @aerialls

Thanks for the PR! I think we should keep printing the version on startup too and exit right after if the flag is set. What do you think?

[aerialls]

Hello 👋🏻
This is what i wanted to do until I saw the "Starting ...". This is why I decided to split in two phrases. But I can rollback this change if needed 😄

[pleshakov]

Hi @aerialls

Thanks for the PR!

In addition to @lucacome 's comment, could you also update the main README the usage section with the description of the new cli argument - https://github.com/nginxinc/nginx-prometheus-exporter#command-line-arguments ?

Also, we don't usually start commit messages with tags like feat(flag). Please take a look at the commit history https://github.com/nginxinc/nginx-prometheus-exporter/commits/master Could you update the commit message? Something like Add version cli argument or Add version flag would make sense.

Cheers

[aerialls]

Hello @pleshakov.
Sorry for the (huge) delay. I've updated the PR following your feedbacks. I hope it's ok now 👍
Thanks!

[pleshakov]

Hi @aerialls

Thanks for addressing the feedback! I have one comment before we merge it. Thanks

[aerialls]

Hi @pleshakov,
I've updated the PR with your feedback!

[pleshakov]

@aerialls Thank you!