Release workflow improvement (#4353)

* heading format

* Remove separators

* workflow

* updates

* Include note about release heading

* fix link

.github/workflows/backport.yml

@@ -12,7 +12,7 @@ jobs:
     steps:
       - uses: actions/checkout@v3
         with:
-          # history is needed in order to do cherry-pick
+          # history is needed to run git cherry-pick below
           fetch-depth: 0
 
       - name: Set git user

.github/workflows/merge-change-log-to-main.yml

@@ -0,0 +1,32 @@
+name: Merge change log to main
+on:
+  workflow_dispatch:
+
+jobs:
+  create-pull-request:
+    runs-on: ubuntu-20.04
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          ref: main
+          # history is needed to run format-patch below
+          fetch-depth: 0
+
+      - name: Set git user
+        run: |
+          git config user.name opentelemetry-java-bot
+          git config user.email [email protected]
+
+        # this will fail if there have been conflicting change log updates introduced in main
+      - name: Create pull request against main
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          git format-patch --stdout main..$GITHUB_REF_NAME CHANGELOG.md | git apply
+          msg="Merge change log updates from $GITHUB_REF_NAME to main"
+          git commit -a -m "$msg"
+          git push origin HEAD:merge-change-log-updates-to-main
+          gh pr create --title "$msg" \
+                       --body "$msg" \
+                       --head merge-change-log-updates-to-main \
+                       --base main

.github/workflows/prepare-release-branch.yml

@@ -29,7 +29,7 @@ jobs:
           git config user.name opentelemetry-java-bot
           git config user.email [email protected]
 
-      - name: Create pull request against release branch
+      - name: Create pull request against the release branch
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         run: |

.github/workflows/release.yml

@@ -95,31 +95,24 @@ jobs:
                             --discussion-category announcements \
                             v$VERSION
 
-      - uses: actions/checkout@v3
-        with:
-          ref: main
-          # history is needed in order to generate the patch
-          fetch-depth: 0
+      - name: Update the change log with the release date
+        run: |
+          date=$(gh release view v$VERSION --json publishedAt --jq .publishedAt | sed 's/T.*//')
+          sed -ri "s/## Version $VERSION .*/## Version $VERSION ($date)/" CHANGELOG.md
 
       - name: Set git user
         run: |
           git config user.name opentelemetry-java-bot
           git config user.email [email protected]
 
-        # this step should be last since it will fail if there have been conflicting
-        # change log updates introduced on the main branch
-      - name: Create pull request to merge any change log updates to main
+      - name: Create pull request against the release branch
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         run: |
-          git format-patch --stdout main..$GITHUB_REF_NAME CHANGELOG.md > patch
-          if [ -s patch ]; then
-            git apply patch
-            msg="Merge change log updates from $GITHUB_REF_NAME to main"
-            git commit -a -m "$msg"
-            git push origin HEAD:merge-change-log-updates-to-main
-            gh pr create --title "$msg" \
-                         --body "$msg" \
-                         --head merge-change-log-updates-to-main \
-                         --base main
-          fi
+          msg="Add $VERSION release date to the change log"
+          git commit -a -m "$msg"
+          git push origin HEAD:add-$VERSION-release-date
+          gh pr create --title "[$GITHUB_REF_NAME] $msg" \
+                       --body "$msg" \
+                       --head add-$VERSION-release-date \
+                       --base $GITHUB_REF_NAME