ci: docker: Combine test and build+publish workflows

.github/workflows/docker.yml

@@ -1,10 +1,13 @@
 name: Docker
 on:
+  pull_request:
   push:
     branches:
       - 'develop'
     tags:
       - 'v?[0-9]+.[0-9]+.[0-9]+'
+env:
+  TEST_TAG: etherpad/etherpad:test
 jobs:
   docker:
     runs-on: ubuntu-latest
@@ -15,8 +18,29 @@ jobs:
       -
         name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v1
+      -
+        name: Build and export to Docker
+        uses: docker/build-push-action@v2
+        with:
+          context: .
+          load: true
+          tags: ${{ env.TEST_TAG }}
+      -
+        name: Set up Node.js
+        uses: actions/setup-node@v2
+        with:
+          node-version: 'lts/*'
+      -
+        name: Test
+        run: |
+          docker run --rm -d -p 9001:9001 ${{ env.TEST_TAG }}
+          ./src/bin/installDeps.sh
+          sleep 3
+          (cd src && npm run test-container)
+          git clean -dxf .
       -
         name: Docker meta
+        if: github.event_name == 'push'
         id: meta
         uses: docker/metadata-action@v3
         with:
@@ -28,16 +52,17 @@ jobs:
             type=semver,pattern={{major}}
       -
         name: Log in to Docker Hub
-        if: github.event_name != 'pull_request'
+        if: github.event_name == 'push'
         uses: docker/login-action@v1
         with:
           username: ${{ secrets.DOCKERHUB_USERNAME }}
           password: ${{ secrets.DOCKERHUB_TOKEN }}
       -
         name: Build and push
+        if: github.event_name == 'push'
         uses: docker/build-push-action@v2
         with:
           context: .
-          push: ${{ github.event_name != 'pull_request' }}
+          push: true
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}

.github/workflows/dockerfile.yml

@@ -1,26 +0,0 @@
-name: "Dockerfile"
-
-# any branch is useful for testing before a PR is submitted
-on: [push, pull_request]
-
-jobs:
-  dockerfile:
-    # run on pushes to any branch
-    # run on PRs from external forks
-    if: |
-         (github.event_name != 'pull_request')
-         || (github.event.pull_request.head.repo.id != github.event.pull_request.base.repo.id)
-    name: build image and run connectivity test
-    runs-on: ubuntu-latest
-
-    steps:
-    - name: Checkout repository
-      uses: actions/checkout@v2
-
-    - name: docker build
-      run: |
-        docker build -t etherpad:test .
-        docker run -d -p 9001:9001 etherpad:test
-        ./src/bin/installDeps.sh
-        sleep 3 # delay for startup?
-        cd src && npm run test-container