Create GitHub Action to auto-publish to PyPI

[whimboo]

When a new release of mozdownload is created we should use the pypi-publish GitHub action to automatically publish the release on https://pypi.org/project/mozdownload/.

[libialany]

I want to contribute, I'm familiar with GitHub Actions.

[whimboo]

Thank you a lot @libialany! I'm looking forward to get your PR #683 reviewed and landed.

[whimboo]

Re-opening because we need a follow-up PR for the remaining issue. @libialany would you be interested to work on that?

[libialany]

I want. Thank you @whimboo . I have two questions: If you accept a merge request, should the GitHub Action to auto-publish run successfully(build, deploy)? Additionally, if the maintainer makes a small change, should the GitHub Action run again? In both cases, right(build, deploy)?

[whimboo]

Actually I wonder if we could change the workflow to not run based on a merge, but when adding a new (release) tag to the repository. That is actually the moment when all the files are ready to get published, and therefore I use the create a new release feature on Github which doesn't have a PR.

Based on that we most likely also don't need the test jobs to run but just the build and deployment steps.

[libialany]

Thank you, @whimboo!

I have an idea for handling releases. For instance, I could trigger an action only when a tag is pushed. Here’s a sample configuration:

on:
  push:
    tags: ['1.[0-9]+.[0-9]+']
jobs:
  on-success:
 ......

Is this the correct way to set it up?, I noticed that the tags consistently start with "1.".

[whimboo]

@libialany Running the action based on a created tag sounds fine with me. But note that we cannot limit it to a name starting with 1.. If there is a backward incompatible change in mozdownload we would have to bump the major version. As such we could do it for each and every tag without restriction. So using - '*' should be fine. Otherwise we could also use a regex like - '[0-9]+.[0-9]+.[0-9]+' to not accidentally run the action if a non-release tag gets added - but that shouldn't happen.