Migrate to Github Actions

[kanekosh]

Purpose

Migrate CI/CD tool from Travis to Github Actions.

• oas_pr.yml is triggered when a PR is created. This runs tests and builds docs (but does not deploy it).
• oas_push.yml is triggered when a PR is merged to master (i.e., pushed to master). In addition to the tests and doc builds, it deploys the docs to gh-pages.

Type of change

What types of change is it?

• Other (maintenance update)

Checklist

• I have run unit and regression tests which pass locally with my changes

[kanekosh]

Just for future reference:
This extension: https://github.com/marketplace/actions/sphinx-build looked helpful, but for some reason it required re-installing everything (openaerostruct, openmdao, mpi4py etc...) in its own block using pre-build-command.
Since these packages are already installed in earlier blocks (for tests), I decided to not use it and directly build the docs via make html.

[coveralls]

Coverage remained the same at 96.6% when pulling 866c1c0 on gh_actions into b36c186 on master.

[kanekosh]

I believe it's working now. If it looks good, I will remove the travis file before merging.
It looks to me that GH Actions is properly blocking the merge (as travis was doing so), but I didn't any settings for that, so I am a bit worried.

[ewu63]

Looks fine. My main question is whether it's possible to combine these into a single file. I don't like the code duplication in two files that are largely the same.

[kanekosh]

Looks fine. My main question is whether it's possible to combine these into a single file. I don't like the code duplication in two files that are largely the same.

Agreed, will take a look, I believe it should be possible.

[ewu63]

One last thing: I believe we want coveralls to run on the PR build also, so that we can monitor the testing coverage and make sure it doesn't decrease by much. On Travis, the after_success stage is run regardless of whether it's a push to master or PR build, and I guess travis-sphinx deploy just failed on PR build since it requires a secret token (set on Travis website) to deploy.

After this is merged I will update the branch protection rule to switch the required status checksfrom Travis to GitHub Actions.

[kanekosh]

I believe it's good to go! I unified two files and added if statements so that docs deployment are only called when we push to the master branch. Coveralls runs on both PR builds and merge builds. I tested the if statements here and it worked.

I also removed the Travis file.

[ewu63]

Awesome stuff! Sorry to be picky but I really wanna make sure we're careful here. Did you ever test that this is working as expected? i.e. push a commit that deliberately broke something and check that GHA fails.

EDIT: I guess that's not super relevant here but with Docker-based builds there was a time where we never checked out the PR, so we were always just testing the Docker image which always passed. I'm happy to merge this as is.

[kanekosh]

I deliberately broke one of the tests, and now GHA fails as it is supposed to.
The documentation build is a bit tricky, though. GHA fails when make html fails, for example when we didn't specify the correct dependencies on requirements.txt. However, when make html finishes with some warnings, GHA does not detect and block that. This happens when embedded python scripts have some errors. In such a case, the docs do have embedded code on them, but since python execution failed, we don't have the python output (like optimization result printout) on the docs.

I am not sure if we can deal with this at the GHA level.

[ewu63]

Yeah that seems like something to figure out with the OpenMDAO toolchain for building docs. We can investigate that in the future. Happy to merge now, just a reminder to make a release after.