[codex] create release tags with dedicated App (#2186)

.github/workflows/auto-tag-on-release-pr-merge.yml

@@ -4,22 +4,18 @@ name: Auto-tag on Release PR Merge
 # prefix; the main chart lane also auto-detects a Chart.yaml version bump so
 # a chart feature PR can publish its own new version when merged:
 #
-#   version-bump/<v>   → tag v<v>        → dispatch release.yml (desktop app)
-#   relay-release/<v>  → tag relay-v<v>  → dispatch docker.yml (relay image)
-#   chart-release/<v>  → tag chart-v<v>  → dispatch helm-chart.yml (main helm chart)
-#   push-chart-release/<v> → tag push-chart-v<v> → dispatch push-gateway-helm-chart.yml
+#   version-bump/<v>   → tag v<v>        → release.yml (desktop app)
+#   relay-release/<v>  → tag relay-v<v>  → docker.yml (relay image)
+#   chart-release/<v>  → tag chart-v<v>  → helm-chart.yml (main helm chart)
+#   push-chart-release/<v> → tag push-chart-v<v> → push-gateway-helm-chart.yml
 #   any internal PR that bumps deploy/charts/buzz/Chart.yaml `version`
-#                       → tag chart-v<v>  → dispatch helm-chart.yml (helm chart)
+#                       → tag chart-v<v>  → helm-chart.yml (helm chart)
 #   mobile-release/<v> → tag mobile-v<v> → (manual sprout_ref for buzz-releases build — see below)
 #
-# The desktop, relay, and chart lanes dispatch their build workflow rather than
-# relying on the consumer's `on.push.tags` trigger: auto-tag pushes the tag
-# with the default GITHUB_TOKEN, which GitHub's recursion guard blocks from
-# firing any `on: push` trigger. So release.yml, docker.yml, and helm-chart.yml
-# all have a `push.tags` trigger that is dead for auto-pushed tags — the
-# dispatch is the real path. Each dispatch passes the bare version and the tag
-# ref so the consumer builds the tagged commit (github.ref on a dispatch is
-# `main`).
+# Release tags are created with a short-lived token from the dedicated
+# buzz-release-bot GitHub App. GitHub attributes the ref creation to that
+# App, so the consumer's `on.push.tags` trigger runs normally. The workflow's
+# default GITHUB_TOKEN remains read-only and is never used to create a tag.
 #
 # The mobile lane is push-only by infosec necessity: OSS `block/buzz` CI must
 # not trigger CI in the private `buzz-releases` repo, so auto-dispatch across
@@ -33,8 +29,7 @@ on:
     branches: [main]
 
 permissions:
-  contents: write
-  actions: write
+  contents: read
 
 jobs:
   auto-tag:
@@ -47,6 +42,7 @@ jobs:
         with:
           ref: ${{ github.event.pull_request.merge_commit_sha }}
           fetch-depth: 0
+          persist-credentials: false
 
       - name: Resolve release lane and version
         id: release
@@ -59,24 +55,19 @@ jobs:
           case "$BRANCH" in
             version-bump/*)
               VERSION="${BRANCH#version-bump/}"
-              TAG_PREFIX="v"
-              DISPATCH="release" ;;
+              TAG_PREFIX="v" ;;
             relay-release/*)
               VERSION="${BRANCH#relay-release/}"
-              TAG_PREFIX="relay-v"
-              DISPATCH="docker" ;;
+              TAG_PREFIX="relay-v" ;;
             chart-release/*)
               VERSION="${BRANCH#chart-release/}"
-              TAG_PREFIX="chart-v"
-              DISPATCH="helm-chart" ;;
+              TAG_PREFIX="chart-v" ;;
             push-chart-release/*)
               VERSION="${BRANCH#push-chart-release/}"
-              TAG_PREFIX="push-chart-v"
-              DISPATCH="push-gateway-helm-chart" ;;
+              TAG_PREFIX="push-chart-v" ;;
             mobile-release/*)
               VERSION="${BRANCH#mobile-release/}"
-              TAG_PREFIX="mobile-v"
-              DISPATCH="" ;;
+              TAG_PREFIX="mobile-v" ;;
             *)
               parent_sha="$(git rev-parse HEAD^)"
               old_version="$(git show "${parent_sha}:deploy/charts/buzz/Chart.yaml" 2>/dev/null | awk '/^version:/ {print $2}')"
@@ -86,8 +77,7 @@ jobs:
                 echo "enabled=false" >> "$GITHUB_OUTPUT"
                 exit 0
               fi
-              TAG_PREFIX="chart-v"
-              DISPATCH="helm-chart" ;;
+              TAG_PREFIX="chart-v" ;;
           esac
           if ! echo "$VERSION" | grep -qE '^[0-9]+\.[0-9]+\.[0-9]+(-[0-9A-Za-z.-]+)?$'; then
             echo "::error::Invalid release version: '$VERSION'"
@@ -95,19 +85,29 @@ jobs:
           fi
           {
             echo "enabled=true"
-            echo "version=$VERSION"
             echo "tag=${TAG_PREFIX}${VERSION}"
-            echo "dispatch=$DISPATCH"
           } >> "$GITHUB_OUTPUT"
           echo "Tagging ${TAG_PREFIX}${VERSION}"
 
+      - name: Create release tagger token
+        if: steps.release.outputs.enabled == 'true'
+        id: release-tagger
+        uses: actions/create-github-app-token@bcd2ba49218906704ab6c1aa796996da409d3eb1 # v3.2.0
+        with:
+          client-id: ${{ vars.BUZZ_RELEASE_TAGGER_CLIENT_ID }}
+          private-key: ${{ secrets.BUZZ_RELEASE_TAGGER_PRIVATE_KEY }}
+          permission-contents: write
+
       - name: Create and push tag
         if: steps.release.outputs.enabled == 'true'
         env:
+          GH_TOKEN: ${{ steps.release-tagger.outputs.token }}
           TAG: ${{ steps.release.outputs.tag }}
         run: |
-          EXISTING_SHA="$(git ls-remote --tags origin "refs/tags/$TAG" | awk '{print $1}')"
-          if [ -n "$EXISTING_SHA" ]; then
+          set -euo pipefail
+          EXISTING_REF="$(gh api "repos/$GITHUB_REPOSITORY/git/ref/tags/$TAG" --jq .ref 2>/dev/null || true)"
+          if [ -n "$EXISTING_REF" ]; then
+            EXISTING_SHA="$(gh api "repos/$GITHUB_REPOSITORY/commits/$TAG" --jq .sha)"
             if [ "$EXISTING_SHA" = "$GITHUB_SHA" ]; then
               echo "Tag $TAG already exists at $GITHUB_SHA — skipping tag creation"
               exit 0
@@ -116,40 +116,7 @@ jobs:
               exit 1
             fi
           fi
-          git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
-          git config user.name "github-actions[bot]"
-          git tag "$TAG"
-          git push origin "$TAG"
-
-      - name: Trigger release build
-        # The desktop, relay, and chart lanes dispatch their build workflow
-        # because the consumer's on:push:tags trigger is dead for tags pushed
-        # by GITHUB_TOKEN (recursion guard — see header comment). Mobile has no
-        # consumer yet, so dispatch="" skips this step entirely.
-        if: steps.release.outputs.enabled == 'true' && steps.release.outputs.dispatch != ''
-        env:
-          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-          DISPATCH: ${{ steps.release.outputs.dispatch }}
-          VERSION: ${{ steps.release.outputs.version }}
-          TAG: ${{ steps.release.outputs.tag }}
-        run: |
-          # Run the workflow itself at the immutable tag so github.sha, OIDC,
-          # provenance, and the checked-out source all name the release commit.
-          extra_args=()
-          case "$DISPATCH" in
-            release) WORKFLOW="release.yml" ;;
-            docker)  WORKFLOW="docker.yml" ;;
-            helm-chart)
-              WORKFLOW="helm-chart.yml"
-              extra_args=(-f "ref=$TAG") ;;
-            push-gateway-helm-chart)
-              WORKFLOW="push-gateway-helm-chart.yml"
-              extra_args=(-f "ref=$TAG") ;;
-            *)
-              echo "::error::Unhandled dispatch target: '$DISPATCH'"
-              exit 1 ;;
-          esac
-          gh workflow run "$WORKFLOW" \
-            --ref "$TAG" \
-            -f version="$VERSION" \
-            "${extra_args[@]}"
+          gh api --method POST "repos/$GITHUB_REPOSITORY/git/refs" \
+            -f ref="refs/tags/$TAG" \
+            -f sha="$GITHUB_SHA" \
+            --silent

.github/workflows/docker.yml

@@ -18,15 +18,13 @@ name: Docker image
 #   - push tags relay-v*.*.* → :{version} + :{major}.{minor} + :{major}
 #                              (+ :latest for stable, NOT for prereleases)
 #   - pull_request           → build only (no push), cache stays warm
-#   - workflow_dispatch      → relay-tag rescue, dispatched at the tag itself
+#   - workflow_dispatch      → manual relay-tag rescue at the tag itself
 #
 # Why workflow_dispatch carries a version input:
-#   auto-tag-on-release-pr-merge.yml pushes relay-v* with the default
-#   GITHUB_TOKEN, which GitHub deliberately does NOT let fire on:push triggers
-#   (recursion guard). So the push:tags trigger above never runs for releases.
-#   auto-tag instead dispatches this workflow at the immutable tag and supplies
-#   the bare version for metadata-action. The workflow rejects a dispatch whose
-#   github.ref, checked-out HEAD, and relay-v tag do not resolve to one commit.
+#   Normal releases arrive through the push:tags trigger above. The input is
+#   retained only for an operator to rerun publication manually at an immutable
+#   relay tag. The workflow rejects a dispatch whose github.ref, checked-out
+#   HEAD, and relay-v tag do not resolve to one commit.
 #   On the rescue path inputs.version is already bare (e.g. 0.3.0), so the
 #   match=^relay-v(.*)$ regex simply no-ops (it warns, leaving the value
 #   intact) and the bare version flows straight to the semver parser. On a
@@ -146,7 +144,7 @@ jobs:
           # own — it only strips refs/tags/, then runs the raw ref through
           # semver.valid(), which rejects "relay-v0.3.0". The match capture
           # group feeds the bare version to the semver parser. value= supplies
-          # the version on the auto-tag rescue dispatch (github.ref is `main`
+          # the version on a manual rescue dispatch (github.ref is `main`
           # there, not the tag): it is already bare, so match no-ops (warns,
           # value intact) and the bare version validates as-is. On push value=
           # is empty, so the ref drives it and match strips relay-v — push

.github/workflows/helm-chart.yml

@@ -9,14 +9,11 @@ name: helm chart
 # `chart-v*` tags publish — `main` pushes and PRs stay lint/render-only so we
 # never overwrite a released chart version from an in-progress `main`.
 #
-# Why workflow_dispatch carries version/ref inputs (same reason as docker.yml):
-#   auto-tag-on-release-pr-merge.yml pushes `chart-v*` with the default
-#   GITHUB_TOKEN, which GitHub's recursion guard blocks from firing any
-#   `on: push` trigger. So the `push.tags` trigger below is dead for
-#   auto-pushed tags — auto-tag instead dispatches this workflow with the bare
-#   version + tag ref, and the publish job checks out inputs.ref and packages at
-#   inputs.version. On a real manual `git push` of a `chart-v*` tag the
-#   push.tags trigger fires and inputs are empty.
+# Why workflow_dispatch carries version/ref inputs:
+#   Normal releases arrive through the `push.tags` trigger below. The inputs are
+#   retained only for an operator to rerun publication manually at an immutable
+#   chart tag; the publish job checks out inputs.ref and packages at
+#   inputs.version.
 
 on:
   workflow_dispatch:
@@ -153,7 +150,7 @@ jobs:
 
   publish:
     # Packages the chart and pushes it to GHCR as an OCI artifact. Fires only on
-    # a `chart-v*` tag push (manual) or the auto-tag rescue dispatch (which
+    # a `chart-v*` tag push or a manual rescue dispatch (which
     # carries inputs.version) — never on `main` pushes or PRs, so an in-progress
     # `main` can never overwrite a released chart version. Mirrors docker.yml's
     # GHCR publish (login with GITHUB_TOKEN, packages: write, fork override var).

RELEASING.md

@@ -59,6 +59,11 @@ with any new commits, and updates the PR in place.
 All three lanes share one engine; they differ only in which version manifest
 they bump, which branch prefix they use, and what the merge triggers.
 
+The merge workflow creates tags with a short-lived installation token from the
+dedicated `buzz-release-bot` GitHub App. Release-tag rules allow that App to
+create matching tags and prevent other actors from creating, moving, or
+deleting them. The workflow's default `GITHUB_TOKEN` is read-only.
+
 ### Desktop
 
 1. **`just release-desktop`** runs locally on `main` — computes the next
@@ -79,15 +84,13 @@ they bump, which branch prefix they use, and what the merge triggers.
    opens (or updates) a PR.
 2. **Merge the PR** — the `auto-tag-on-release-pr-merge` workflow detects the
    `relay-release/*` branch merge and pushes a `relay-v<version>` tag.
-3. **Auto-tag dispatches `docker.yml`** — the same workflow then triggers
-   `docker.yml` with the version and tag ref, which builds the multi-arch relay
+3. **Tag triggers `docker.yml`** — the `relay-v<version>` push triggers
+   `docker.yml`, which builds the multi-arch relay
    image and publishes `ghcr.io/block/buzz:<version>` (plus `:<major>.<minor>`,
    `:<major>`, and `:latest` for stable releases). Prereleases
    (`relay-v<version>-rc.1`) publish only the prerelease tag and do **not**
-   move `:latest`. (The dispatch — rather than relying on `docker.yml`'s
-   `push: tags` trigger — is required because GitHub suppresses `on: push` for
-   tags pushed by the workflow's own `GITHUB_TOKEN`; the desktop lane dispatches
-   `release.yml` for the same reason.)
+   move `:latest`. GitHub runs the tag trigger because the tag is created by
+   the dedicated GitHub App rather than the workflow's `GITHUB_TOKEN`.
 
 Every push to `main` continues to build and publish `:main` + `:sha-<7>` tags
 (the rolling development image). The `:latest` tag tracks the latest **stable**

scripts/test-release-ref-contract.sh

@@ -53,7 +53,16 @@ fi
 grep -q 'verify-release-ref\.sh' "$repo_root/.github/workflows/release.yml"
 grep -q 'verify-release-ref\.sh' "$repo_root/.github/workflows/docker.yml"
 grep -q 'test-release-ref-contract\.sh' "$repo_root/.github/workflows/ci.yml"
-grep -Fq -- "--ref \"\$TAG\"" \
-  "$repo_root/.github/workflows/auto-tag-on-release-pr-merge.yml"
+auto_tag="$repo_root/.github/workflows/auto-tag-on-release-pr-merge.yml"
+grep -q 'actions/create-github-app-token@' "$auto_tag"
+grep -q 'client-id:.*vars\.BUZZ_RELEASE_TAGGER_CLIENT_ID' "$auto_tag"
+grep -q 'private-key:.*secrets\.BUZZ_RELEASE_TAGGER_PRIVATE_KEY' "$auto_tag"
+grep -q 'permission-contents: write' "$auto_tag"
+grep -q 'GH_TOKEN:.*steps\.release-tagger\.outputs\.token' "$auto_tag"
+grep -Fq 'git/refs' "$auto_tag"
+if grep -q 'gh workflow run' "$auto_tag"; then
+  echo "auto-tag still dispatches a publisher instead of using the tag push" >&2
+  exit 1
+fi
 
 echo "release ref contract passed"