ci(town-crier): auto-resolve bus thread on 2-approval consensus #9
Workflow file for this run
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| # Drop this into a repo at .github/workflows/announce-pr.yml to make it a town-crier producer. | |
| # | |
| # Setup (once per repo or org): | |
| # - Variable TOWN_CRIER_URL = https://<app>.fly.dev | |
| # - Secret TOWN_CRIER_TOKEN = the bearer token minted for "github-action" | |
| # | |
| # Produces the FULL lifecycle of a request, so the bus never drifts from GitHub: | |
| # - announce: "Agent Review Requested" lands on a PR (or a new commit is pushed) -> tell the crier. | |
| # - resolve (close): the PR closes/merges or its review label is removed -> retire its thread. | |
| # - resolve (consensus): a 2nd independent approval lands with no outstanding change request -> retire the | |
| # thread; consensus is reached, so further review turns are just churn. | |
| # Without these a landed/settled PR sits "open" on the bus forever (there is no GitHub->bus merge sync). | |
| # The consensus job counts only approvals cast at the CURRENT head, so a stale approval from an earlier push | |
| # can't satisfy consensus on a reopened thread — robust regardless of the repo's dismiss-stale-reviews setting. | |
| # The bus never stores approval state; the job reads the live count and calls the EXISTING resolve verb. | |
| # Joined harnesses pick up open requests from the bus — this workflow does NOT poll or review. | |
| # | |
| # Failure policy (two distinct modes, so a real problem is never silently masked): | |
| # - MISSING provisioning (no TOWN_CRIER_URL/TOKEN) is a config error -> fail LOUD (red). | |
| # - A bus HICCUP (cold start / transient 5xx / timeout) or an unreadable review list -> ::warning:: + | |
| # stay GREEN (fail-open; a coordination-layer blip must never red a contributor's PR checks). | |
| # The announce/resolve jobs use no GITHUB_TOKEN (they auth to the bus with TOWN_CRIER_TOKEN); the consensus | |
| # job needs pull-requests:read to count approvals, granted at job scope only. | |
| name: town-crier producer (announce + resolve + consensus) | |
| permissions: {} | |
| on: | |
| pull_request: | |
| # labeled -> first announce; synchronize -> re-announce each new commit (re-review on push); | |
| # unlabeled/closed -> resolve (de-announce). A synchronize on an unlabelled PR is ignored by the if. | |
| types: [labeled, synchronize, unlabeled, closed] | |
| pull_request_review: | |
| # submitted -> a review landed; the consensus job checks whether 2 independent approvals now agree. | |
| types: [submitted] | |
| jobs: | |
| announce: | |
| if: >- | |
| (github.event.action == 'labeled' && github.event.label.name == 'Agent Review Requested') || | |
| (github.event.action == 'synchronize' && contains(github.event.pull_request.labels.*.name, 'Agent Review Requested')) | |
| runs-on: ubuntu-latest | |
| steps: | |
| - name: Announce to the crier | |
| env: | |
| CRIER_URL: ${{ vars.TOWN_CRIER_URL }} | |
| CRIER_TOKEN: ${{ secrets.TOWN_CRIER_TOKEN }} | |
| PR_URL: ${{ github.event.pull_request.html_url }} | |
| REPO: ${{ github.repository }} | |
| TITLE: ${{ github.event.pull_request.title }} | |
| REQUESTER: ${{ github.event.pull_request.user.login }} | |
| # The head SHA is the change detector: a re-announce with the same head is a no-op on the | |
| # bus; a new head reopens the thread for a fresh review round. | |
| HEAD_OID: ${{ github.event.pull_request.head.sha }} | |
| run: | | |
| # Missing provisioning is a config error — fail LOUD so it can't pass silently. | |
| if [ -z "$CRIER_URL" ] || [ -z "$CRIER_TOKEN" ]; then | |
| echo "::error::town-crier not provisioned — set the TOWN_CRIER_URL variable + TOWN_CRIER_TOKEN secret" | |
| exit 1 | |
| fi | |
| # jq builds the JSON so a PR title with quotes can't break the payload. | |
| # A bus hiccup is not the PR's fault — degrade to a warning, keep the check green. | |
| curl -fsS --max-time 10 -X POST "$CRIER_URL/announce" \ | |
| -H "Authorization: Bearer $CRIER_TOKEN" \ | |
| -H "Content-Type: application/json" \ | |
| -d "$(jq -n \ | |
| --arg pr "$PR_URL" \ | |
| --arg repo "$REPO" \ | |
| --arg title "$TITLE" \ | |
| --arg requester "$REQUESTER" \ | |
| --arg head_oid "$HEAD_OID" \ | |
| '{pr_url:$pr, repo:$repo, title:$title, requester:$requester, head_oid:$head_oid}')" \ | |
| || echo "::warning::town-crier announce failed (transient bus issue?) — not blocking the PR" | |
| resolve: | |
| if: (github.event.action == 'closed' && contains(github.event.pull_request.labels.*.name, 'Agent Review Requested')) || (github.event.action == 'unlabeled' && github.event.label.name == 'Agent Review Requested') | |
| runs-on: ubuntu-latest | |
| steps: | |
| - name: Resolve on the crier | |
| env: | |
| CRIER_URL: ${{ vars.TOWN_CRIER_URL }} | |
| CRIER_TOKEN: ${{ secrets.TOWN_CRIER_TOKEN }} | |
| PR_URL: ${{ github.event.pull_request.html_url }} | |
| ACTION: ${{ github.event.action }} | |
| MERGED: ${{ github.event.pull_request.merged }} | |
| run: | | |
| if [ -z "$CRIER_URL" ] || [ -z "$CRIER_TOKEN" ]; then | |
| echo "::error::town-crier not provisioned — set the TOWN_CRIER_URL variable + TOWN_CRIER_TOKEN secret" | |
| exit 1 | |
| fi | |
| if [ "$ACTION" = "unlabeled" ]; then | |
| NOTE="review label removed" | |
| elif [ "$MERGED" = "true" ]; then | |
| NOTE="merged" | |
| else | |
| NOTE="closed without merge" | |
| fi | |
| curl -fsS --max-time 10 -X POST "$CRIER_URL/resolve" \ | |
| -H "Authorization: Bearer $CRIER_TOKEN" \ | |
| -H "Content-Type: application/json" \ | |
| -d "$(jq -n --arg pr "$PR_URL" --arg note "$NOTE" '{pr_url:$pr, note:$note}')" \ | |
| || echo "::warning::town-crier resolve failed (transient bus issue?) — not blocking the PR" | |
| consensus: | |
| # A review landed — if it's an approval on a labelled PR, retire the bus thread once TWO independent | |
| # approvals agree with no outstanding change request. We read the live count (filtered to the current | |
| # head, so stale approvals can't satisfy consensus) rather than tracking it on the bus. | |
| if: >- | |
| github.event.review.state == 'approved' && | |
| contains(github.event.pull_request.labels.*.name, 'Agent Review Requested') | |
| runs-on: ubuntu-latest | |
| permissions: | |
| pull-requests: read # read the PR's reviews to count approvals (GITHUB_TOKEN, this job only) | |
| steps: | |
| - name: Resolve on consensus | |
| env: | |
| CRIER_URL: ${{ vars.TOWN_CRIER_URL }} | |
| CRIER_TOKEN: ${{ secrets.TOWN_CRIER_TOKEN }} | |
| GH_TOKEN: ${{ github.token }} | |
| REPO: ${{ github.repository }} | |
| PR_NUMBER: ${{ github.event.pull_request.number }} | |
| PR_URL: ${{ github.event.pull_request.html_url }} | |
| HEAD_OID: ${{ github.event.pull_request.head.sha }} | |
| run: | | |
| if [ -z "$CRIER_URL" ] || [ -z "$CRIER_TOKEN" ]; then | |
| echo "::error::town-crier not provisioned — set the TOWN_CRIER_URL variable + TOWN_CRIER_TOKEN secret" | |
| exit 1 | |
| fi | |
| # Tally the LATEST opinionated review per reviewer (ignore COMMENTED/PENDING), counting an | |
| # approval ONLY if it was cast at the CURRENT head — a stale approval from an earlier push must | |
| # not satisfy consensus on a reopened thread (correct regardless of dismiss_stale_reviews). | |
| # NDJSON via --paginate --jq '.[]' then slurp with jq -s — avoids `gh api --slurp` (newer-gh only). | |
| tally="$(gh api --paginate "repos/$REPO/pulls/$PR_NUMBER/reviews" --jq '.[]' \ | |
| | jq -s --arg head "$HEAD_OID" ' | |
| map(select(.state == "APPROVED" or .state == "CHANGES_REQUESTED" or .state == "DISMISSED")) | |
| | group_by(.user.login) | map(max_by(.submitted_at)) | |
| | {approved: (map(select(.state == "APPROVED" and .commit_id == $head)) | length), | |
| changes: (map(select(.state == "CHANGES_REQUESTED")) | length), | |
| who: (map(select(.state == "APPROVED" and .commit_id == $head)) | map(.user.login) | join(", "))}' \ | |
| )" || { echo "::warning::could not read PR reviews (transient?) — not blocking the PR"; exit 0; } | |
| approved="$(printf '%s' "$tally" | jq -r '.approved')" | |
| changes="$(printf '%s' "$tally" | jq -r '.changes')" | |
| who="$(printf '%s' "$tally" | jq -r '.who')" | |
| echo "approvals=$approved changes_requested=$changes approvers=[$who]" | |
| # Consensus = >= 2 distinct CURRENT-HEAD approvals AND no outstanding change request. | |
| if [ "${approved:-0}" -lt 2 ] || [ "${changes:-0}" -ne 0 ]; then | |
| echo "no consensus yet — leaving the thread open for another turn" | |
| exit 0 | |
| fi | |
| NOTE="consensus: ${approved} approvals (${who}) @${HEAD_OID:0:12}" | |
| curl -fsS --max-time 10 -X POST "$CRIER_URL/resolve" \ | |
| -H "Authorization: Bearer $CRIER_TOKEN" \ | |
| -H "Content-Type: application/json" \ | |
| -d "$(jq -n --arg pr "$PR_URL" --arg note "$NOTE" '{pr_url:$pr, note:$note}')" \ | |
| || echo "::warning::town-crier consensus-resolve failed (transient bus issue?) — not blocking the PR" |