Label PRs that contain breaking changes based on the changelog (#1769)

Co-authored-by: Trask Stalnaker <trask.stalnaker@gmail.com>

Author: lmolkova

.github/workflows/prepare-new-issue.yml

@@ -10,9 +10,6 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - name: Run update permissions
-        run: chmod +x ./.github/workflows/scripts/prepare-new-issue.sh
-
       - name: Run prepare-new-issue.sh
         run: ./.github/workflows/scripts/prepare-new-issue.sh
         env:

.github/workflows/prepare-new-pr.yml

@@ -0,0 +1,32 @@
+name: 'Prepare new PR'
+on:
+  pull_request_target:
+    types: [opened, synchronize]
+    branches: [ 'main*' ]
+    paths: ['.chloggen/*']
+
+jobs:
+  prepare-new-pr:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      pull-requests: write
+    if: ${{ github.repository_owner == 'open-telemetry' }}
+    steps:
+      # check out main
+      - uses: actions/checkout@v4
+      # sparse checkout to only get the .chloggen directory
+      - uses: actions/checkout@v4
+        with:
+          ref: ${{ github.head_ref }}
+          path: prchangelog
+          sparse-checkout: .chloggen
+
+      # we're going to run prepare-new-pr script from the main branch
+      # to parse changelog record from the PR branch.
+      - name: Run prepare-new-pr.sh
+        run: ./.github/workflows/scripts/prepare-new-pr.sh
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          PR: ${{ github.event.pull_request.number }}
+          PR_CHANGELOG_PATH: prchangelog

.github/workflows/scripts/prepare-new-pr.sh

@@ -0,0 +1,39 @@
+#!/usr/bin/env bash
+#
+# Copyright The OpenTelemetry Authors
+# SPDX-License-Identifier: Apache-2.0
+#
+# This script uses chloggen file to get the change_type and adds it as a label to the PR.
+# If there are none or multiple changelog files, it will ignore the PR.
+#
+# Notes:
+#  - label should exist in the repository in order to add it to the PR.
+#  - if label already exist, this is a no-op.
+#  - if any error happens, the script quietly exits with 0.
+
+if [ -z ${PR:-} ]; then
+    echo "PR number is required"
+    exit 1
+fi
+
+if [ -z ${PR_CHANGELOG_PATH:-} ]; then
+    echo "PR_CHANGELOG_PATH is required"
+    exit 1
+fi
+
+CHLOG="$(gh pr view $PR --json files --jq '.files.[].path | select (. | startswith(".chloggen/"))')"
+echo "Change log file(s): ${CHLOG}"
+
+if [ -z "$CHLOG" ]; then
+    echo "No changelog found in the PR. Ignoring this change."
+    exit 0
+fi
+
+COUNT="$(echo "$CHLOG" | wc -l)"
+if [ $COUNT -eq 1 ]; then
+    CHANGE_TYPE=$(awk -F': ' '/^change_type:/ {print $2}' "$PR_CHANGELOG_PATH/$CHLOG" | xargs)
+    echo $CHANGE_TYPE
+    gh pr edit "${PR}" --add-label "${CHANGE_TYPE}" || true
+else
+    echo "Found multiple changelog files. Ignoring this change."
+fi