Replace docker.sh script with GitHub Actions

Author: der-eismann

.github/workflows/docker.yml

@@ -3,7 +3,7 @@ name: Build Docker image
 on: [push, pull_request]
 
 jobs:
-  ubuntu:
+  container:
     runs-on: ubuntu-latest
     steps:
     - name: Checkout master branch
@@ -26,14 +26,30 @@ jobs:
       run: black --check docker/*.py
     - name: Run isort in check mode
       run: isort --settings-file docker/.isort.cfg docker/*.py  --check --diff
+    - name: Running linter
+      run: docker run --rm -i hadolint/hadolint:2.6.0 < Dockerfile || exit 1
+    - name: Docker metadata generation
+      id: meta
+      uses: docker/metadata-action@v4
+      with:
+        images: |
+          ${{ github.repository }}
+        tags: |
+          type=ref,event=branch
+          type=ref,event=pr
+          type=semver,pattern={{version}}
+          type=semver,pattern={{major}}.{{minor}}
+    - name: Login to Docker Hub
+      if: ${{ github.repository == 'oracle/opengrok' && github.event_name == 'push' }}
+      uses: docker/login-action@v2
+      with:
+        username: ${{ secrets.DOCKER_USERNAME }}
+        password: ${{ secrets.DOCKER_PASSWORD }}
     - name: Build and optionally push Docker image
-      env:
-        DOCKER_USERNAME: ${{ secrets.DOCKER_USERNAME }}
-        DOCKER_PASSWORD: ${{ secrets.DOCKER_PASSWORD }}
-        OPENGROK_REPO_SLUG: ${{ github.repository }}
-        OPENGROK_PULL_REQUEST: ${{ github.head_ref }}
-        OPENGROK_REF: ${{ github.ref }}
-      run: ./dev/docker.sh
+      uses: docker/build-push-action@v4
+      with:
+        push: ${{ github.repository == 'oracle/opengrok' && github.event_name == 'push' }}
+        tags: ${{ steps.meta.outputs.tags }}
     - name: Install Python pre-requisites
       run: python3 -m pip install requests
     - name: Optionally update README on Docker hub