build: Improve GitHub Actions caching and reproducibility (#422)

Author: jakubjanecek

.github/workflows/build.yml

@@ -6,17 +6,18 @@ on:
 
 jobs:
   build:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v2
       - name: Set up JDK 1.8
         uses: actions/setup-java@v1
         with:
           java-version: 1.8
+      - uses: coursier/cache-action@v5
       - name: Check/Compile/Test
         run: sbt check
   update_release_draft:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
       - uses: release-drafter/release-drafter@v5
         env:

.github/workflows/pull.yml

@@ -3,12 +3,15 @@ on: [pull_request]
 
 jobs:
   build:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v2
       - name: Set up JDK 1.8
         uses: actions/setup-java@v1
         with:
           java-version: 1.8
+      - uses: coursier/cache-action@v5
+        with:
+          extraKey: pr-${GITHUB_HEAD_REF}
       - name: Check/Compile/Test
         run: sbt check

.github/workflows/release.yml

@@ -5,15 +5,14 @@ on:
 
 jobs:
   build:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v2
       - name: Set up JDK 1.8
         uses: actions/setup-java@v1
         with:
           java-version: 1.8
-      - name: Install GPG
-        uses: olafurpg/setup-gpg@v3
+      - uses: coursier/cache-action@v5
       - name: Check/Compile/Test
         run: sbt check
       - name: Release
@@ -23,11 +22,19 @@ jobs:
           SONATYPE_USERNAME: ${{ secrets.SONATYPE_USERNAME }}
           SONATYPE_PASSWORD: ${{ secrets.SONATYPE_PASSWORD }}
         run: sbt ci-release
+      - uses: actions/cache@v1
+        with:
+          path: vendor/bundle
+          key: ${{ runner.os }}-gems
+          restore-keys: |
+            ${{ runner.os }}-gems
       - uses: actions/setup-ruby@v1
         with:
           ruby-version: '2.6'
       - name: Install jekyll
-        run: gem install jekyll -v 4.0.0
+        run: |
+          export GEM_HOME=${PWD}/vendor/bundle
+          gem install jekyll -v 4.0.0
       - name: Publish Microsite
         env:
           DEPLOY_KEY: ${{ secrets.DEPLOY_KEY }}