chore(ci): add daily librarian workflow to update googleapis commitish

Author: zhumin8

.github/workflows/update_librarian_googleapis.yaml

@@ -0,0 +1,105 @@
+# Copyright 2026 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+name: Update librarian googleapis commitish
+on:
+  schedule:
+  - cron: '0 3 * * *' # Run once a day at 3:00 AM UTC
+  workflow_dispatch: # Allow manual trigger
+jobs:
+  update-librarian-googleapis:
+    runs-on: ubuntu-24.04
+    defaults:
+      run:
+        working-directory: google-cloud-java
+    steps:
+    - name: Checkout google-cloud-java
+      uses: actions/checkout@v6
+      with:
+        repository: googleapis/google-cloud-java
+        path: google-cloud-java
+        fetch-depth: 0
+    - name: Check for Open PR
+      env:
+        GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      run: |
+        set -x
+        current_branch="update-librarian-googleapis-main"
+        
+        # Try to find an open pull request associated with the branch
+        pr_num=$(gh pr list -s open -H "${current_branch}" -q . --json number | jq ".[] | .number")
+        
+        if [ -n "${pr_num}" ]; then
+          echo "Error: An open Pull Request already exists for this update: PR #${pr_num}."
+          echo "Please merge or close the existing PR before running this workflow again."
+          exit 1 # Fails this step and the workflow
+        fi
+    - name: Set up Go
+      uses: actions/setup-go@v5
+      with:
+        go-version: '>=1.20.2'
+    - name: Run librarian update
+      run: |
+        version=$(go run github.com/googleapis/librarian/cmd/librarian@latest config get version)
+        go run "github.com/googleapis/librarian/cmd/librarian@${version}" update sources.googleapis
+    - name: Detect Changes
+      id: detect
+      run: |
+        git add librarian.yaml
+        changed_files=$(git diff --cached --name-only)
+        if [[ "${changed_files}" == "" ]]; then
+          echo "has_changes=false" >> $GITHUB_OUTPUT
+          echo "No changes in librarian.yaml"
+        else
+          echo "has_changes=true" >> $GITHUB_OUTPUT
+          
+          # Get the new commit hash
+          new_commit=$(git diff --cached librarian.yaml | grep -E '^\+    commit:' | head -n 1 | awk '{print $3}')
+          echo "new_commit=${new_commit}" >> $GITHUB_OUTPUT
+          
+          if [ -n "${new_commit}" ]; then
+            echo "title=chore: update googleapis commitish to ${new_commit:0:7}" >> $GITHUB_OUTPUT
+            echo "body=Updated googleapis commitish in librarian.yaml to https://github.com/googleapis/googleapis/commit/${new_commit}" >> $GITHUB_OUTPUT
+          else
+            echo "title=chore: update googleapis commitish in librarian.yaml" >> $GITHUB_OUTPUT
+            echo "body=Updated googleapis commitish in librarian.yaml to the latest version." >> $GITHUB_OUTPUT
+          fi
+        fi
+    - name: Commit and Create PR
+      if: steps.detect.outputs.has_changes == 'true'
+      env:
+        GH_TOKEN: ${{ secrets.CLOUD_JAVA_BOT_GITHUB_TOKEN }}
+        PR_TITLE: ${{ steps.detect.outputs.title }}
+        PR_BODY: ${{ steps.detect.outputs.body }}
+      run: |
+        set -x
+        [ -z "$(git config user.email)" ] && git config --global user.email "cloud-java-bot@google.com"
+        [ -z "$(git config user.name)" ] && git config --global user.name "cloud-java-bot"
+        
+        base_branch="main"
+        current_branch="update-librarian-googleapis-${base_branch}"
+        
+        # Create and switch to the branch (force checkout -B to discard any local state on this branch name if it existed)
+        git checkout -B "${current_branch}"
+        
+        # Commit the changes (they are already staged by the Detect Changes step!)
+        git commit -m "${PR_TITLE}"
+        
+        # Push to remote (force push to overwrite any stale branch on remote)
+        git remote add remote_repo https://cloud-java-bot:"${GH_TOKEN}@github.com/${{ github.repository }}.git" || git remote set-url remote_repo https://cloud-java-bot:"${GH_TOKEN}@github.com/${{ github.repository }}.git"
+        git fetch -q remote_repo
+        git push -f remote_repo "${current_branch}"
+        
+        # Create the PR
+        gh pr create --title "${PR_TITLE}" --head "${current_branch}" --body "${PR_BODY}" --base "${base_branch}"