Core Tor Continuous Integration

Locations of existing public repositories

(These are the sites hosting official Tor repositories or repositories of individual developers.)

• git.torproject.org (canonical repo is here)
• oniongit.eu (experimental/pilot self-hosted GitLab?)
• gitlab.com
• github.com

Locations of existing CI platforms

• pixelminers buildbot (BSD architectures only?; fed only by canonical repo on git.tpo)
• jenkins.torproject.org (self-hosted; fed only by canonical repo on git.tpo)
• oniongit.eu (self-hosted GitLab CI; resource-limited; only builds team member repos)
• gitlab.com
• travis-ci.org (fed by github.com)

Tradeoffs

• GitLab is open source
• GitHub is closed source
• GitHub has a much larger user base. Network effects are important. (Also, we can't really expect external contributors to create an account on our self-hosted GitLab!)
• Travis is easiest for any of us to fix when it breaks. Even external contributors can help if they have a fork! Just editing one file (.travis.yml is enough for most things). It also can build stuff pre-merge (including pull requests!).
• Very few people have access to fix Jenkins when it breaks. Its summary output is also hard to read/navigate
• Jenkins covers more platforms, while Travis covers fewer. It also can't build stuff pre-merge.
• Appveyor is one way to get Windows coverage and is about as easy as Travis to set up
• The ability to build (and run tests on) branches and pull requests before they get merged does amazing things to improve code quality and save reviewers effort.

Changes

• New code review will be in the form of pull requests on github.com. This allows us to see whether a contribution even builds before spending effort manually reviewing it.
• Travis will be our primary CI in that we'll expect it to always work on master or release branches. We'll drop everything to fix it if it breaks.
• Appveyor will probably also be in this category when we get it set up.

Remaining the same for now

• git.torproject.org is still our canonical repository
• issue tracking remains at trac.torproject.org (pull requests need an associated Trac ticket; we can help newcomers with this if need be)

To Do

• Taylor will email network-team with near-term recommendations [DONE]
  • how to set up accounts on github and travis
  • major changes (near-term)
• Investigate 32-bit stuff on Travis (e.g., 32-bit package whitelists for containerized builds)
• Set up Appveyor
• Write documentation for contributors

Stuff to defer

• what to do about the confusing existence of two similarly-named org accounts (torproject and thetorproject) on github.com
• what to do about making accidentally hitting the big shiny merge button less of a problem (it might not be that big a problem in practice)