Android-components: Let bot do: Rebase -> All Green? -> Land

[pocmo]

It's too time consuming to manually update a PR, check back later and merge or update PR again. It would be much nicer if we could do something like:

• Add [needs landing] label
• Bot comes along and:
  
  
  
  • Checks out PR
  
  
  • Rebases PR
  
  
  • Builds, runs tests etc.
  
  
• If all green: Bot merges PR
• If red: Bot removes label and comments

There are some existing solutions:

• Servo uses bors: https://github.com/graydon/bors
• @jonalmeida mentioned Homu: https://github.com/barosl/homu

[pocmo]

Another option would be to do that from a taskcluster task that is triggered by a hook. We may want to have a build cache first, so that we can build rebased PRs pretty quickly: #638

[jonalmeida]

I'm not particular to either one, but homu might work better with a taskcluster as our custom CI. I'll ask around in the Rust #infra channel if anyone has done this already.

[jonalmeida]

bors can integrate without too much of a problem with any CI that posts either commit statuses or checks

So we should be good.

well, our bot account is called bors, but the software behind it is actually homu

Turns out their the same thing!

[pocmo]

This is kind of soft-blocked on utilizing the cache API: We need fast builds to make this work without causing more pain.

[jonalmeida]

There was a recommendation from the Rust #infra channel to use bors-ng which has taskcluster support already: https://github.com/bors-ng/bors-ng/blob/45de72ba106e0cabe7fddc4152c09e9c6adef83f/bors.toml#L1

Servo's bors config: https://github.com/servo/saltfs/blob/2a56d14c47d637dabe55c2f83a3088d35896cfc9/homu/files/cfg.toml#L286-L287

This is kind of soft-blocked on utilizing the cache API: We need fast builds to make this work without causing more pain.

Seems fair. I was curious about the tools required so I did some basic perusing. 😃

[pocmo]

I played with bors-ng a bit in a different repository. This looks great and I think we should try it! I'll add this issue to the triage list. :)

[jonalmeida]

https://i.giphy.com/media/5GoVLqeAOo6PK/giphy.webp

[pocmo]

Closing: Bors is running now. Let's see how it is going to be. :)