how to reuse gradle cache in GitHub workflow

Question

I am trying to to keep the gradle cache in my GitHub workflow, but it is not working. I am new to gradle and am struggling to find out how/why I am unable to keep the gradle cache between workflow builds of my project

in my GitHub workflow file, I have two gradle caches. One of the gradle cache and the other one is the gradle wrapper:

      - name: Setup Gradle Dependencies Cache
        uses: actions/cache@v2
        with:
          path: ~/.gradle/caches
          key: ${{ runner.os }}-gradle-caches-${{ hashFiles('**/*.gradle', '**/*.gradle.kts') }}
      - name: Setup Gradle Wrapper Cache
        uses: actions/cache@v2
        with:
          path: ~/.gradle/wrapper
          key: ${{ runner.os }}-gradle-wrapper-${{ hashFiles('**/gradle/wrapper/gradle-wrapper.properties') }}

Locally a ./gradlew clean followed by a ./gradlew build will build my project in about 33 seconds... On GitHub, it takes 3 times as long (?): https://github.com/jactor-rises/jactor-persistence/runs/4794532441?check_suite_focus=true

How can I set up an effective cache of dependencies and wrapper in a GitHub workflow?

Answer 1

For workflows triggered in main branch:

try gradle/gradle-build-action@v2 as mentioned in the gradle docs and github docs.

name: Build Gradle project

on:
  push:

jobs:
  build-gradle-project:
    runs-on: ubuntu-latest
    steps:
    - name: Checkout project sources
      uses: actions/checkout@v3
    - name: Setup Gradle
      uses: gradle/gradle-build-action@v2
    - name: Run build with Gradle Wrapper
      run: ./gradlew build

For workflows triggered in branches other than main:

try gradle/gradle-build-action@v2 with cache-read-only: false

1: for all branches

      - name: Setup Gradle
        uses: gradle/gradle-build-action@v2
        with:
         cache-read-only: false

2: for specific branches

      - name: Setup Gradle
        uses: gradle/gradle-build-action@v2
        with:
         cache-read-only: ${{ github.ref != 'refs/heads/main' && github.ref != 'refs/heads/release' }}

Note: this option will most likely only work for workflows triggered by push because github.ref value might be different in other cases as mentioned here.