Add GitHub actions workflow to tag new releases from .github/piper-cut-cl.json

.github/ci_support/tag_release_version.sh

@@ -0,0 +1,114 @@
+#!/bin/bash
+set -e
+
+err_exit() {
+  printf "$@\n" >&2
+  exit 1
+}
+
+usage_exit() {
+  cat <<_eof_
+USAGE: $(basename "$0") PIPER_CUT_CL VERSION_ID
+
+PIPER_CUT_CL - # of the CL where a release was cut
+VERSION_ID - the id of the release, in the format vYYYYMMDD
+
+_eof_
+  printf '====\n'
+  err_exit "$@"
+}
+
+# Expect a single argument specifying the release cut CL number
+find_piper_cut_commit() {
+  local -r cut_cl=$1
+  # 1. Get git commit IDs and their corresponding CLs from the git log.
+  # 2. select and print the commit ID associated with the highest CL# that is
+  # still lower than the cut CL
+  git_commit_cl_log | last_commit_before_cl "$cut_cl"
+}
+
+# Read the git log and produce lines of the form
+#
+# `COMMIT_ID CL_NUMBER`
+git_commit_cl_log() {
+  # PiperOrigin-RevId: indicates the CL number
+  git log master \
+    --format='format:%h %(trailers:key=PiperOrigin-RevId,separator=,valueonly=true)'
+}
+
+# Expect a single argument specifying the release cut CL number
+#
+# Expect input lines in the form:
+# `COMMIT_ID [CL_NUMBER]`
+#
+# Further expect that the CL numbers are in decscending order.
+#
+# Print the first CL number we encounter that is lower than
+# the argument CL number.
+#
+# Report an error and return a non-zero value if we are unable
+# to print a result CL number for any reason.
+last_commit_before_cl() {
+  awk -v cut_cl="$1" '
+  # In some cases there is no CL associated with a commit.
+  # We skip all of those by ignoring lines with only one field.
+  NF > 1 {
+    # force the CL to be interpreted as an integer
+    cl = + $2
+    if (cl <= cut_cl) {
+      found_commit = 1
+      print $1
+      # skip reading any more records
+      exit
+    }
+  }
+
+  END {
+    # This section always gets executed
+    if (!found_commit) {
+      printf "no commit found: Earliest CL seen is %d which is > %d\n",
+        cl, cut_cl > "/dev/stderr"
+      exit 1
+    }
+  }
+  '
+}
+
+main() {
+    local -r piper_cut_cl=$1
+    local -r version_id=$2
+
+    existing=$(git tag -l "$version_id")
+    # Check if the version ID is already tagged.
+    if [ -n "$existing" ]; then
+      echo "Tag already exists for version '$version_id'"
+      exit 0
+    fi
+
+    COMMIT=$(find_piper_cut_commit $piper_cut_cl)
+    # check that the commit variable is not empty
+    if [[ -z "$COMMIT" ]]; then
+      echo "No commit found prior to CL $piper_cut_cl"
+      exit 1
+    fi
+
+    echo "Tagging commit $COMMIT with version $version_id"
+    git tag -a "$version_id" -m "Release $version_id" "$COMMIT"
+    git push origin master "$version_id"
+}
+
+(( $# == 2 )) || usage_exit 'incorrect argument count\n' "$@"
+
+readonly PIPER_CUT_CL=$1
+readonly VERSION_ID=$2
+
+if [[ ! "$PIPER_CUT_CL" =~ ^[0-9]+$ ]]; then
+    usage_exit "Invalid Piper cut CL number: '$PIPER_CUT_CL'"
+fi
+
+if [[ ! "$VERSION_ID" =~ ^v[0-9]+$ ]]; then
+    usage_exit "Invalid version ID: '$VERSION_ID'. Expected format is vYYYYMMDD."
+fi
+
+main "$PIPER_CUT_CL" "$VERSION_ID"
+

.github/workflows/ci.yaml

@@ -185,3 +185,65 @@ jobs:
         env:
           SONATYPE_USERNAME: closure-compiler
           SONATYPE_PASSWORD: ${{ secrets.SONATYPE_PASSWORD }}
+
+  tag_release_version_id:
+    name: Tag Release Version ID
+    # Run on a push to master but not on a pull request
+    # Pull requests are not necessarily trusted to configure the
+    # correct release tag.
+    if: ${{ github.event_name == 'push' }}
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+    steps:
+    # Checkout the piper-cut-cl.json from the most recent two commits
+    - name: Checkout Current closure-compiler Commit
+      # https://github.com/marketplace/actions/checkout
+      uses: actions/checkout@v4
+      with:
+        fetch-depth: 2
+        sparse-checkout: |
+          .github/piper-cut-cl.json
+          .github/ci_support/tag_release_version.sh
+        sparse-checkout-cone-mode: false
+
+    - id: detect_changes
+      run: |
+        PIPER_DIFF=$(git diff HEAD~1 -- .github/piper-cut-cl.json)
+        FOUND_NEW_RELEASE=$([ -n "$PIPER_DIFF" ] && echo "true" || echo "false")
+        echo "foundNewRelease=$FOUND_NEW_RELEASE" >> "$GITHUB_OUTPUT"
+        echo "foundNewRelease: $FOUND_NEW_RELEASE"
+
+    - id: set_piper_json_vars
+      if: ${{ steps.detect_changes.outputs.foundNewRelease == 'true' }}
+      # https://docs.github.com/en/actions/writing-workflows/choosing-what-your-workflow-does/accessing-contextual-information-about-workflow-runs#steps-context
+      run: |
+        {
+            echo 'piperJson<<EOF'
+            cat ./.github/piper-cut-cl.json
+            echo EOF
+        } >> "$GITHUB_OUTPUT"
+
+    # Check out all historical commits
+    # This is much more expensive than just checking out the most recent
+    # 2 commits, as done above, so only do this if actually cutting a release
+    - name: Checkout all closure-compiler commits and tags
+      uses: actions/checkout@v4
+      if: ${{ steps.detect_changes.outputs.foundNewRelease == 'true' }}
+      with:
+        # a depth of 0 triggers a fetch of all historical commits/branches/tags
+        # https://github.com/marketplace/actions/checkout#Fetch-all-history-for-all-tags-and-branches
+        fetch-depth: 0
+
+    - name: Tag cut CL
+      id: tag_cut_cl
+      if: ${{ steps.detect_changes.outputs.foundNewRelease == 'true' }}
+      run: |
+          git config --global user.name "${GITHUB_ACTOR}"
+          git config --global user.email "${GITHUB_ACTOR}@users.noreply.github.com"
+          .github/ci_support/tag_release_version.sh \
+              "${{ fromJson(env.piperJson).piper_cut_cl }}" \
+              "${{ fromJson(env.piperJson).version_id }}";
+      env:
+        piperJson: ${{ steps.set_piper_json_vars.outputs.piperJson }}
+        GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}