4.5 KiB
Branch protection on main
main is gated by a declarative branch-protection policy. The source of truth is .github/branch-protection.json; the apply mechanism is scripts/apply-branch-protection.sh. Re-running the script with a changed JSON is idempotent.
This page explains what the policy says and how to change it.
Current policy
| Setting | Value | Why |
|---|---|---|
| Required status checks (strict) | Classify Changes, Check AGENTS.md Links, Test Workspace, Test omnigraph-server --features aws, CODEOWNERS / drift, CODEOWNERS / noedit |
Every PR must pass workspace tests, AGENTS.md link integrity, and the CODEOWNERS hygiene checks. strict: true requires the branch to be up-to-date with main before merge. |
| Required approving reviews | 1 |
At least one reviewer. With a 2-person team, going higher would block all merges when one person is unavailable. |
| Require code-owner reviews | true |
The reviewer must be a code owner per .github/CODEOWNERS. This is what makes the codeowners chassis enforced. |
| Dismiss stale reviews on new commits | true |
A push after approval invalidates the prior review. Prevents the "approve, then sneak in unreviewed changes" pattern. |
| Require linear history | true |
No merge commits — squash or rebase only. Matches recent practice. |
| Disallow force pushes | true |
No history rewrites on main. |
| Disallow branch deletions | true |
main cannot be deleted. |
| Required conversation resolution | true |
All review comment threads must be resolved before merge. |
| Enforce on admins | true |
Even repository admins go through the gates. The point is no bypasses. |
| Required signed commits | not yet | Not enabled. Would lock out maintainers until everyone enrolls GPG/SSH commit signing. Tracked as a follow-up. |
How to apply
Run from the repository root:
./scripts/apply-branch-protection.sh
The script reads .github/branch-protection.json, strips the human-readable _comment field (the GitHub API rejects unknown keys), and PUTs to repos/ModernRelay/omnigraph/branches/main/protection.
Requires gh authenticated with a token that has admin permissions on the repository.
To preview without applying:
DRY_RUN=1 ./scripts/apply-branch-protection.sh
How to change the policy
- Edit
.github/branch-protection.json. - Open a PR. The JSON change goes through normal review.
- After the PR merges, an admin runs
./scripts/apply-branch-protection.shto push the new policy to GitHub.
The script is not run automatically by CI. Branch-protection changes are admin actions that should be applied deliberately — a CI-driven automatic apply would mean any merged PR could rewrite protection rules, which defeats the purpose. The script's existence makes the apply reproducible; the admin's manual invocation is the audit point.
How to read the current GitHub state
gh api repos/ModernRelay/omnigraph/branches/main/protection
Outputs the live policy. Compare against .github/branch-protection.json to detect drift.
Why declared as code
- Audit trail:
git log .github/branch-protection.jsonshows every change with a reviewable diff and a merge commit. - Disaster recovery: if branch protection is accidentally removed or weakened via the UI, the JSON is the canonical recovery point.
- Consistency: pairs with
.github/codeowners-roles.yml(the CODEOWNERS source of truth). Repository policy lives in the repository.
What this gates
After branch protection is applied, every PR targeting main must:
- Pass all listed status checks.
- Be up-to-date with
main(rebase or merge-from-main). - Have at least one approving review from a code owner for the touched paths.
- Have all review conversations resolved.
- Be squash- or rebase-merged (no merge commits).
Even repository admins are subject to these rules.
Subsequent hardening (not in this PR)
The branch-protection policy is the foundation. Future hardening adds:
- Required signed commits (
required_signatures: true) — once maintainers enroll GPG/SSH signing. - Tag protection for
v*tags viarepos/.../tags/protection. - Required reviewers from specific teams for high-leverage paths (e.g.,
docs/dev/invariants.md) via CODEOWNERS tier expansion + the N-unique-approvers CI workaround. - More required CI checks:
cargo deny,cargo audit,cargo fmt --check,cargo clippy -D warnings, CodeQL, secret scanning, schema-lint (MR-946).
See the hardening playbook for the full plan.