resolves #168 migrate CI to GitHub Actions

[slonopotamus]

No description provided.

[slonopotamus]

Example run: https://github.com/slonopotamus/docker-asciidoctor/runs/1546816395?check_suite_focus=true

Obviously, you'll need to add DOCKERHUB_SOURCE_TOKEN and/or DOCKERHUB_TRIGGER_TOKEN to GitHub Actions secrets in order to make deployment work on https://github.com/asciidoctor/docker-asciidoctor/settings/secrets/actions

[slonopotamus]

Also, current repository settings require Travis build to pass successfully before PR can be merged. This cannot be satisfied anymore because I'm removing Travis build file :)

[dduportal]

Thanks for this great work, of for your patience before having a review!

Some feedbacks have been added if it is ok for you?

[dduportal]

LGTM great job!

Approving this as my last comment is a nice to have (and not blocking the PR in any way).

[dduportal]

• The Travis CI check had been removed
• The 2 secrets have been added

=> I'm adding an empty commit to this PR to trigger a first GH action build (as it seems to require a repository's collaborator to start)

[slonopotamus]

Note that I did not test that upload to docker actually works, though I don't see any reasons why it shouldn't after secrets are added.

[slonopotamus]

You can't test upload in a PR because PRs do not have access to repo secrets neither on Travis nor on GitHub Actions, this is a security measure.

[dduportal]

No problem @slonopotamus! Thank you for this excellent work. I've merged the PR to allow testing (and first gh action setup) on master branch to benefit from the secrets.

[dduportal]

You can't test upload in a PR because PRs do not have access to repo secrets neither on Travis nor on GitHub Actions, this is a security measure.
Our messages crossed, thanks a lot for this precision!

[slonopotamus]

Hmm... Deploy cannot access secrets... I guess we need to expose secrets via environment variables to Makefile. A couple of minutes, will create a follow-up PR.

[slonopotamus]

I think #171 should do the trick.

[dduportal]

@slonopotamus yes, you might want to define an env: directive in the deploy section as underlined in https://docs.github.com/en/actions/reference/encrypted-secrets#using-encrypted-secrets-in-a-workflow to expose the secret to environment

[slonopotamus]

We could also declare it a Makefile bug: Makefile doesn't return non-zero exit code when deploy fails.

[dduportal]

We could also declare it a Makefile bug: Makefile doesn't return non-zero exit code when deploy fails.

Yes, totally! And I might be the culprit for that 😅