tree 4cd8ea5f9660b51e0999b4b89f94673bfb786de2
parent c877a7cc4d7ef7fcaeda097dcbfb79f37b930565
author Han Seoul-Oh <laughinghan@gmail.com> 1488004645 -0800
committer Han Seoul-Oh <laughinghan@gmail.com> 1488004645 -0800

CI: Add Many-Worlds build link to Commit Status

So [Many-Worlds] is this thing I hacked together on Gomix that can fetch,
build, and serve any branch, PR, or commit of MathQuill, on demand. For
example, if you go to:

  http://many-worlds.gomix.me/mathquill/mathquill/branch/master/test/unit.html

then it will fetch the latest `master` branch, run `make test`, then
delegate to a static file server to serve `test/unit.html` and
`build/mathquill.test.js` and all that good stuff.

[Many-Worlds]: https://gomix.com/#!/project/many-worlds

Currently, though, manually formatting that URL is the only way to use
it. What would be nice is if an auto-generated URL were generated per
branch or PR or commit or something and available on GitHub, so you
could just click a link to try out a PR. We could automatically post a
comment on new PRs, but that would spam PR authors with notifications.

A better, quieter way is to use the GitHub Commit Status API:
https://developer.github.com/v3/repos/statuses/

This lets us quietly attach a link to every commit built by CircleCI
without spamming anyone with notifications, and lets you try out
intermediate commits on a PR; not just the tip, every push.

Authentication
--------------

CircleCI doesn't provide us with the token they use for their status
update, probably for good security reasons, but this is exactly what the
MathQuillBot GitHub bot user is for.

`$GITHUB_STATUS_API_KEY` is a [personal access token] for MathQuillBot
limited to the [`repo:status`] authorization scope (so this token can't
be used to write to anything other than commit statuses) that I've added
to the build environment.

[personal access token]: https://help.github.com/articles/creating-an-access-token-for-command-line-use/
[`repo:status`]: https://developer.github.com/v3/oauth/#scopes