(WIP) EkaCI

This tool is meant to provide an optimized reviewing experience for small to large nix package repositories. In particular, the tool should provide:

• succinct PR review workflows
  • Does the eval still succeed?
  • Only inspected builds that have changed
    • Added, removed, [newly/still] succeeding, [newly/still] failing builds
  • Closure size difference
  • Retained dependency differences
  • Captured logs
  • Explore dependency failures (similar to hydra)
  • (Stretch goal) Diffoscope like diff of package outputs?
  • (Strech goal) diffs of NixOS configurations.

Ultimately, this tool is meant to answer, "should I merge this PR" in the quickest manner possible. Curating a Nix repository should not be highly limited to manual review processes of a reviewer. This doesn't scale well, and is error prone.

Design

See the design document for details about a high-level overview of EkaCI.

MVP Roadmap

Server + evaluator + build queue

• GitHub OAuth
  • Allow users to register through GitHub
• GitHub webhooks
  • App registration workflow
  • Receive PR review events
  • Send check gates
• PR Review workflow
  • Git checkout
  • Evaluate derivation differences between head and base branch
  • Queue changed derivations for build
  • Allow successful builds to push outputs to attic
  • Calculate changed metrics between builds: build and runtime closure size, dependencies
• Push built artifacts
  • Allow for a time-lease to be configured for "jobsets", to enable attic integration

Frontend

• GitHub OAuth, allow users to review as github user
• Review PR portal
  • Ordered list of PRs available for review
    • Default ordering: Rebuild count, then by lines changed?
  • Link back to PR, to allow for comments and requesting changes
• PR review
  • Textual diff
  • Metrics view: build+runtime closure size and dependencies
  • Added, removed, [newly/still] building, [newly/still] failing builds
  • Allow for approvals + merges

(Future) Evaluation modes

• "Legacy" (needed for MVP)
  • Similar to "legacy jobsets" in hydra.
  • Allows for an arbitrary expression to be evaluated returning an attrset of derivations
  • A diff of new/changed/removed attrs from the base branch to head branch will create a "check_run" for each new and changed drv
• "OfBorg" Convention
  • Read attr path from commit message to determine package rebuild to rebuild
  • (For ekapkgs and userpkgs) would like for the ability to select downstream build strategy
    • For ekapkgs, just have the package in question and immediate referrers rebuild
    • For userpkgs, just limit to the package in question. Unlikely to have dependencies to other userpkgs'
• Flake checks
  • Similar to garnix
  • Simple, "for each check, create a check_run with the status"
• Flake develop actions
  • For use with nix develop --command <impure command>
  • Similar to gitlab's script runner, just impurely runs code
  • Devshell is retained through gcroots