ci: configure the protected branch

.github/workflows/ci.yaml

@@ -1,113 +1,103 @@
-# Copyright 2022 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.
-# Github action job to test core java library features on
-# downstream client libraries before they are released.
-on:
+'on':
   push:
     branches:
-    - main
-  pull_request:
+      - 2.1.x
+  pull_request: null
 name: ci
 jobs:
   units:
     runs-on: ubuntu-latest
     strategy:
       fail-fast: false
       matrix:
-        java: [8, 11, 17, 25]
+        java:
+          - 8
+          - 11
+          - 17
+          - 25
     steps:
-    - uses: actions/checkout@v4
-    - uses: actions/setup-java@v4
-      with:
-        distribution: temurin
-        java-version: ${{matrix.java}}
-    - run: java -version
-    - run: .kokoro/build.sh
-      env:
-        JOB_TYPE: test
+      - uses: actions/checkout@v4
+      - uses: actions/setup-java@v4
+        with:
+          distribution: temurin
+          java-version: ${{matrix.java}}
+      - run: java -version
+      - run: .kokoro/build.sh
+        env:
+          JOB_TYPE: test
   windows:
     runs-on: windows-latest
     steps:
-    - name: Support longpaths
-      run: git config --system core.longpaths true
-    - uses: actions/checkout@v4
-    - uses: actions/setup-java@v4
-      with:
-        distribution: temurin
-        java-version: 8
-    - run: java -version
-    - run: .kokoro/build.bat
-      env:
-        JOB_TYPE: test
+      - name: Support longpaths
+        run: git config --system core.longpaths true
+      - uses: actions/checkout@v4
+      - uses: actions/setup-java@v4
+        with:
+          distribution: temurin
+          java-version: 8
+      - run: java -version
+      - run: .kokoro/build.bat
+        env:
+          JOB_TYPE: test
   dependencies:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        java: [8, 11, 17, 25]
+        java:
+          - 8
+          - 11
+          - 17
+          - 25
     steps:
-    - uses: actions/checkout@v4
-    - uses: actions/setup-java@v4
-      with:
-        distribution: temurin
-        java-version: ${{matrix.java}}
-    - run: java -version
-    - run: .kokoro/dependencies.sh
+      - uses: actions/checkout@v4
+      - uses: actions/setup-java@v4
+        with:
+          distribution: temurin
+          java-version: ${{matrix.java}}
+      - run: java -version
+      - run: .kokoro/dependencies.sh
   lint:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
-    - uses: actions/setup-java@v4
-      with:
-        distribution: temurin
-        java-version: 11
-    - run: java -version
-    - run: .kokoro/build.sh
-      env:
-        JOB_TYPE: lint
+      - uses: actions/checkout@v4
+      - uses: actions/setup-java@v4
+        with:
+          distribution: temurin
+          java-version: 11
+      - run: java -version
+      - run: .kokoro/build.sh
+        env:
+          JOB_TYPE: lint
   clirr:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
-    - uses: actions/setup-java@v4
-      with:
-        distribution: temurin
-        java-version: 8
-    - run: java -version
-    - run: .kokoro/build.sh
-      env:
-        JOB_TYPE: clirr
-  # compilation failure for sub-modules using source and target options 7 (this  setting cannot be upgraded to Java 21 because some modules support max of Java 8)
-  # Hence compile in Java 8 and test in Java 21.
+      - uses: actions/checkout@v4
+      - uses: actions/setup-java@v4
+        with:
+          distribution: temurin
+          java-version: 8
+      - run: java -version
+      - run: .kokoro/build.sh
+        env:
+          JOB_TYPE: clirr
   units-java21:
-    # Building using Java 8 and run the tests with Java 21 runtime
-    name: "units (21)"
+    name: units (21)
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
-    - uses: actions/setup-java@v4
-      with:
-        java-version: 21
-        distribution: temurin
-    - name: "Set jvm system property environment variable for surefire plugin (unit tests)"
-      # Maven surefire plugin (unit tests) allows us to specify JVM to run the tests.
-      # https://maven.apache.org/surefire/maven-surefire-plugin/test-mojo.html#jvm
-      run: echo "SUREFIRE_JVM_OPT=-Djvm=${JAVA_HOME}/bin/java" >> $GITHUB_ENV
-      shell: bash
-    - uses: actions/setup-java@v4
-      with:
-        java-version: 8
-        distribution: temurin
-    - run: .kokoro/build.sh
-      env:
-        JOB_TYPE: test
+      - uses: actions/checkout@v4
+      - uses: actions/setup-java@v4
+        with:
+          java-version: 21
+          distribution: temurin
+      - name: >-
+          Set jvm system property environment variable for surefire plugin (unit
+          tests)
+        run: echo "SUREFIRE_JVM_OPT=-Djvm=${JAVA_HOME}/bin/java" >> $GITHUB_ENV
+        shell: bash
+      - uses: actions/setup-java@v4
+        with:
+          java-version: 8
+          distribution: temurin
+      - run: .kokoro/build.sh
+        env:
+          JOB_TYPE: test