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Compass Engineering Docs

runner-image

Builds the compass-runner container image from the Nix closure, stages it, and uses rootless BuildKit with a hardened runtime base. The image carries the runner, its VMM userland, and the guest assets.

Run

Section titled “Run”

From the repository root, start a reachable BuildKit daemon and set BUILDKIT_HOST. Create a Docker config with GHCR credentials before publishing:

Terminal window
moon run compass-runner-image:build
sha12="$(git rev-parse HEAD | cut -c1-12)"
DOCKER_CONFIG="/path/to/docker-config" \
  bun tools/runner-image/publish.ts \
    --lane runner --repo ghcr.io/rigelbuild/compass-runner --sha "$sha12"
REGISTRY_AUTH_FILE="/path/to/ghcr-auth.json" \
RUNNER_IMAGE_CLOSURE_PATHS="<newline-separated paths>" \
  bun tools/runner-image/retag.ts \
    --lane runner --repo ghcr.io/rigelbuild/compass-runner --tag v1.2.3 \
    --release-sha "$(git rev-parse HEAD)"

publish-runner-image builds the local OCI layout and calls the shared publish CLI with --lane runner. release-runner-image calls the shared retag CLI with --lane runner. The latter needs full git history and RUNNER_IMAGE_CLOSURE_PATHS from the workflow environment.

Credentials

Section titled “Credentials”

publish.ts reads DOCKER_CONFIG/config.json for BuildKit and skopeo GHCR auth. The publish-runner-image job writes that file using secrets.GITHUB_TOKEN. retag.ts uses the auth file named by REGISTRY_AUTH_FILE; the release-runner-image job creates it with skopeo login and secrets.GITHUB_TOKEN. Both jobs grant packages: write.

Rotate

Section titled “Rotate”

GitHub issues GITHUB_TOKEN per run and rotates it automatically. Both jobs create temporary registry auth files, so there is no long-lived registry token to rotate.