chore(ci): create pull request on changelog update

.github/scripts/create_pr_for_staged_changes.sh

@@ -0,0 +1,116 @@
+#!/bin/bash
+set -uxo pipefail # enable debugging, prevent accessing unset env vars, prevent masking pipeline errors to the next command
+
+#docs
+#title              :create_pr_for_staged_changes.sh
+#description        :This script will create a PR for staged changes and detect and close duplicate PRs.
+#author		    :@heitorlessa
+#date               :May 8th 2023
+#version            :0.1
+#usage		    :bash create_pr_for_staged_changes.sh {git_staged_files_or_directories_separated_by_space}
+#notes              :Meant to use in GitHub Actions only. Temporary branch will be named $TEMP_BRANCH_PREFIX-$GITHUB_RUN_ID
+#os_version         :Ubuntu 22.04.2 LTS
+#required_env_vars  :COMMIT_MSG, PR_TITLE, TEMP_BRANCH_PREFIX, GH_TOKEN, GITHUB_RUN_ID, GITHUB_SERVER_URL, GITHUB_REPOSITORY
+#==============================================================================
+
+PR_BODY="This is an automated PR created from the following workflow"
+FILENAME=".github/scripts/$(basename "$0")"
+readonly PR_BODY
+readonly FILENAME
+
+# Sets GitHub Action with error message to ease troubleshooting
+function raise_validation_error() {
+    echo "::error file=${FILENAME}::$1"
+    exit 1
+}
+
+function debug() {
+    echo "::debug::$1"
+}
+
+function notice() {
+    echo "::notice file=${FILENAME}::$1"
+}
+
+function has_required_config() {
+    # Default GitHub Actions Env Vars: https://docs.github.com/en/actions/learn-github-actions/variables#default-environment-variables
+    debug "Do we have required environment variables?"
+    test -z "${TEMP_BRANCH_PREFIX}" && raise_validation_error "TEMP_BRANCH_PREFIX env must be set to create a PR"
+    test -z "${GH_TOKEN}" && raise_validation_error "GH_TOKEN env must be set for GitHub CLI"
+    test -z "${COMMIT_MSG}" && raise_validation_error "COMMIT_MSG env must be set"
+    test -z "${PR_TITLE}" && raise_validation_error "PR_TITLE env must be set"
+    test -z "${GITHUB_RUN_ID}" && raise_validation_error "GITHUB_RUN_ID env must be set to trace Workflow Run ID back to PR"
+    test -z "${GITHUB_SERVER_URL}" && raise_validation_error "GITHUB_SERVER_URL env must be set to trace Workflow Run ID back to PR"
+    test -z "${GITHUB_REPOSITORY}" && raise_validation_error "GITHUB_REPOSITORY env must be set to trace Workflow Run ID back to PR"
+
+    set_environment_variables
+}
+
+function set_environment_variables() {
+    WORKFLOW_URL="${GITHUB_SERVER_URL}"/"${GITHUB_REPOSITORY}"/actions/runs/"${GITHUB_RUN_ID}" # e.g., heitorlessa/aws-lambda-powertools-test/actions/runs/4913570678
+    TEMP_BRANCH="${TEMP_BRANCH_PREFIX}"-"${GITHUB_RUN_ID}"                                     # e.g., ci-changelog-4894658712
+
+    export readonly WORKFLOW_URL
+    export readonly TEMP_BRANCH
+}
+
+function has_anything_changed() {
+    debug "Is there an update to the source code?"
+    HAS_ANY_SOURCE_CODE_CHANGED="$(git status --porcelain)"
+
+    test -z "${HAS_ANY_SOURCE_CODE_CHANGED}" && echo "Nothing to update" && exit 0
+}
+
+function create_temporary_branch_with_changes() {
+    debug "Creating branch ${TEMP_BRANCH}"
+    git checkout -b "${TEMP_BRANCH}"
+
+    debug "Committing staged files: $*"
+    git add "$@"
+    git commit -m "${COMMIT_MSG}"
+
+    debug "Creating branch remotely"
+    git push origin "${TEMP_BRANCH}"
+}
+
+function create_pr() {
+    debug "Creating PR against ${BRANCH} branch"
+    NEW_PR_URL=$(gh pr create --title "${PR_TITLE}" --body "${PR_BODY}: ${WORKFLOW_URL}" --base "${BRANCH}") # e.g, https://github.com/awslabs/aws-lambda-powertools/pull/13
+
+    # greedy remove any string until the last URL path, including the last '/'. https://opensource.com/article/17/6/bash-parameter-expansion
+    NEW_PR_ID="${NEW_PR_URL##*/}" # 13
+    export NEW_PR_URL
+    export NEW_PR_ID
+}
+
+function close_duplicate_prs() {
+    debug "Do we have any duplicate PRs?"
+    DUPLICATE_PRS=$(gh pr list --search "${PR_TITLE}" --json number --jq ".[] | select(.number != ${NEW_PR_ID}) | .number") # e.g, 13\n14
+
+    debug "Closing duplicated PRs if any"
+    echo "${DUPLICATE_PRS}" | xargs -L1 gh pr close --delete-branch --comment "Superseded by #${NEW_PR_ID}"
+    export readonly DUPLICATE_PRS
+}
+
+function report_summary() {
+    debug "Creating job summary"
+    echo "### Pull request created successfully :rocket: #${NEW_PR_URL} <br/><br/> Closed duplicated PRs (if any): ${DUPLICATE_PRS}" >>"$GITHUB_STEP_SUMMARY"
+
+    notice "PR_URL is ${NEW_PR_URL}"
+    notice "PR_BRANCH is ${TEMP_BRANCH}"
+    notice "PR_DUPLICATES are ${DUPLICATE_PRS}"
+}
+
+function main() {
+    # Sanity check
+    has_anything_changed
+    has_required_config
+
+    create_temporary_branch_with_changes "$@"
+    create_pr
+    close_duplicate_prs
+
+    report_summary
+}
+
+main "$@"

.github/workflows/reusable_publish_changelog.yml

@@ -3,9 +3,6 @@ name: Build and publish latest changelog
 on:
   workflow_call:
 
-permissions:
-  contents: write
-
 env:
   BRANCH: develop
 
@@ -16,6 +13,9 @@ jobs:
     concurrency:
       group: changelog-build
     runs-on: ubuntu-latest
+    permissions:
+      contents: write
+      pull-requests: write
     steps:
       - name: Checkout repository # reusable workflows start clean, so we need to checkout again
         uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab  # v3.5.2
@@ -30,11 +30,16 @@ jobs:
           git pull origin "${BRANCH}"
       - name: "Generate latest changelog"
         run: make changelog
-      - name: Update Changelog in trunk
-        run: |
-          HAS_CHANGE=$(git status --porcelain)
-          test -z "${HAS_CHANGE}" && echo "Nothing to update" && exit 0
-          git add CHANGELOG.md
-          git commit -m "update changelog with latest changes"
-          git pull origin "${BRANCH}" # prevents concurrent branch update failing push
-          git push origin HEAD:refs/heads/"${BRANCH}"
+      - name: Create PR
+        run: bash .github/scripts/create_pr_for_staged_changes.sh CHANGELOG.md
+        env:
+          COMMIT_MSG: "chore(ci): update changelog with latest changes"
+          PR_TITLE: "chore(ci): changelog rebuild"
+          TEMP_BRANCH_PREFIX: "ci-changelog"
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      - name: Cleanup orphaned branch
+        if: failure()
+        run: git push origin --delete "${TEMP_BRANCH_PREFIX}-${GITHUB_RUN_ID}" || echo "Must have failed before creating temporary branch; no cleanup needed."
+        env:
+          TEMP_BRANCH_PREFIX: "ci-changelog"
+          GITHUB_RUN_ID: ${{ github.run_id }}