# Background The [Glasgow Haskell Compiler](https://ghc.haskell.org/) is planning a migration to GitLab. GHC's infrastructure is currently: * Trac for ticket tracking and wiki * gitolite and a variety of custom tooling for repository hosting * Phabricator for code review * a mix of CircleCI (for Linux, macOS) and Appveyor (for Windows) for CI Those responsible for GHC's infrastructure has been in touch with GitLab (namely @dplanella). # Goals The main goals for a successful migration would be: * More accessible infrastructure for contributors * Code review integration with git * Reliable and maintainable multi-platform continuous integration * Streamlined infrastructure and tooling * Good relationship and open communication channel with upstream (GitLab in this case) # Discussion Currently the migration is underway. [Tools](https://github.com/bgamari/trac-to-remarkup/tree/master/src/Trac) for migrating Trac tickets and the wiki into GitLab are largely complete. A staging installation can be found [here](https://gitlab.staging.haskell.org/). ## GitLab replacements | Tool | Feature | GitLab feature | GitLab edition | |:----------- |:---------------------------------- |:---------------------------------- |:--------------- | | Gitolite | GitHub -> Git mirroring | Repository mirroring | EE | | Gitolite | Git -> GitHub mirroring | Repository mirroring | EE | | Trac | Tickets | Issues | CE | | Trac | [Ticket lists](https://ghc.haskell.org/trac/ghc/wiki/Status/GHC-8.6.3) | Issue boards | CE | | Trac | Ticket notifications mailing list | ? | ? | | Trac | Ticket priority | Issue weight | EE | | Trac | Wiki | Wiki | CE | | Phabricator | Herald for automatic reviewer assignment | Code owners | EE | | Phabricator | Code review | Discussions | CE | | Phabricator | Continuous integration | Pipelines | CE | | CircleCI | Continuous integration | Pipelines with [custom CircleCI bridge tool](https://gitlab.staging.haskell.org/alp/ghc-ci) | CE | | Appveyor | Continuous integration | Pipelines and Appveyor's GitLab integration | CE | # Outstanding issues ## Blockers * [x] Issues/API: Import difficulties due to gitlab-ce#46980 * [x] Issues: Commit notes aren't created if ticket is created after commit is pushed (gitlab-ce#56943; worked around). ## Urgent * [ ] Difficult to run certain CI jobs only on merge requests (gitlab-ce#56418) * [x] Gitaly loses its mind on an otherwise normal repository (gitlab-ce#57067) * [x] Functional `gitlab-runner` support on Windows. This might be either accomplished by * fixing https://gitlab.com/gitlab-org/gitlab-runner/issues/3856, * following through on https://gitlab.com/gitlab-org/gitlab-runner/issues/2609. It looks like there is motion along these lines on https://gitlab.com/groups/gitlab-org/-/epics/535 * [x] Functional artifact uploads on Windows (gitlab-runner#3035) * [ ] Approvers are spammed with large quantities of email (gitlab-ee#4816) ## Important but not urgent * `gitlab-runner` * [ ] `gitlab-runner` fails to heartbeat while running a job on Windows (https://gitlab.com/gitlab-org/gitlab-runner/issues/3854) * [ ] `gitlab-runner` support for AArch64: https://gitlab.com/gitlab-org/gitlab-runner/merge_requests/725, https://gitlab.com/gitlab-org/gitlab-runner/issues/2137 * [ ] `gitlab-runner` support for msys2 (https://gitlab.com/gitlab-org/gitlab-runner/issues/1699) * [ ] `gitlab-runner` leaves old Docker volumes around (gitlab-runner#2980) * Issues: * [ ] Closed milestones not shown in milestones line (gitlab-ce#25091) * [x] Issues are incorrectly closed by commits containing `doesn't fix #NNNN` in their commit message (gitlab-ce#55970) * [ ] Issue search via issue number is broken (gitlab-ce#30974) * Code review: * [x] Send one email notification per published code review gitlab-ee#4326. * [ ] Finding changes between merge request revisions is quite difficult (gitlab-ce#51336) * [ ] Very difficult to orient oneself in long reviews (gitlab-ce#52485) * [ ] Finding new inline comments is quite hard (gitlab-ce#56481) * [ ] Automatically rebase stale MRs marked as "merge when pipelines pass" (&521) * [ ] Attach non-inline comments to transactional reviews (gitlab-ee#8225) ## Important but not prioritized by GitLab * [ ] Pipelines: No way to build all commits (gitlab-ce#53799) * [ ] Wiki: Non-developers can't view wiki history (gitlab-ce#14620) ## Nice to have * [ ] Issues: Issue search autocompletion should be less selective (gitlab-ce#57249) * [ ] Code review: Comments not allowed on unchanged lines (gitlab-ce#51823) * [x] Code review: file tree (gitlab-ce#46474) * [x] Pipelines: Need to custom bridge tool to integrate with CircleCI (need mitigated by migration away from CircleCI) * [ ] Pipelines: Difficulty of managing builder images, no story for Docker on Windows. Potentially helped by gitlab-runner!464, gitlab-runner#2885 * [ ] Pipelines: No way to query triggered pipeline status (gitlab-ee#5096) * [ ] gitlab-runner: `extends` keywords is broken in some cases (gitlab-runner#3794) * [ ] gitlab-runner: `gitlab-runner` violates the principle of least privilege (gitlab-runner#3188) * [ ] Issues: Label namespace clutter due to lack of custom fields (https://gitlab.com/gitlab-org/gitlab-ee/issues/1906, &235) * [ ] Issues: Better handling of duplicate and blocking ticket relationships (gitlab-ce#47007, gitlab-ce#39751) * [x] Repository mirror: Crash (gitlab-ce#55350) * [ ] Code review: Convenient way to fold all resolved discussions (gitlab-ce#55747) * [ ] Code review: Allow user to rewrite commit message while squashing during merge (gitlab-ee#1510) * [ ] Code review: Button to toggle visibility of all discussions (gitlab-ce#19149) * [ ] Search: Be more clever in identifying user intent for searching on IDs (gitlab-ce#56967) * [x] Poor search relevance: fix ElasticSearch support (gitlab-ee#9633) # Status The migration effort is on a fairly aggressive timeline due to various considerations. The plan is to switch over to GitLab by December 18. There is a test instance [here](https://gitlab.staging.haskell.org/). This is a self-hosted GitLab Ultimate installation provided through the [GitLab FOSS initiative](https://gitlab.com/gitlab-com/marketing/community-relations/opensource-program/gitlab-oss/merge_requests/217) which includes an import of GHC's Trac tickets and users from a few months ago. After migration there are a # Collaborators * @bgamari * @dplanella