Enhance GitHub Actions workflow to build and push Docker images to GitHub Container Registry

Author: lygris

.github/workflows/docker-build.yml

@@ -9,15 +9,38 @@ on:
 jobs:
   build:
     runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write # Grant write permission to packages
     steps:
     - name: Checkout repository
       uses: actions/checkout@v4
 
+    - name: Log in to GitHub Container Registry
+      uses: docker/login-action@v3
+      with:
+        registry: ghcr.io
+        username: ${{ github.actor }}
+        password: ${{ secrets.GITHUB_TOKEN }}
+
     - name: Build and tag the Docker image
       run: |
-        docker build . --file Dockerfile --tag doh-server:latest
-        # If you want to push to Docker Hub, uncomment the following lines
-        # and ensure DOCKER_USERNAME and DOCKER_PASSWORD are set as GitHub Secrets.
-        # echo "${{ secrets.DOCKER_PASSWORD }}" | docker login -u "${{ secrets.DOCKER_USERNAME }}" --password-stdin
-        # docker tag doh-server:latest your_dockerhub_username/doh-server:latest
-        # docker push your_dockerhub_username/doh-server:latest
+        IMAGE_NAME=doh-server
+        IMAGE_TAG=${{ github.sha }}
+        # Use lowercase for owner and repo name for GHCR compatibility
+        REPO_OWNER=$(echo ${{ github.repository_owner }} | tr '[:upper:]' '[:lower:]')
+        REPO_NAME=$(echo ${{ github.event.repository.name }} | tr '[:upper:]' '[:lower:]')
+        GHCR_IMAGE=ghcr.io/$REPO_OWNER/$REPO_NAME/$IMAGE_NAME
+
+        docker build . --file Dockerfile --tag $GHCR_IMAGE:latest --tag $GHCR_IMAGE:$IMAGE_TAG
+
+    - name: Push the Docker image to GitHub Container Registry
+      run: |
+        IMAGE_NAME=doh-server
+        IMAGE_TAG=${{ github.sha }}
+        REPO_OWNER=$(echo ${{ github.repository_owner }} | tr '[:upper:]' '[:lower:]')
+        REPO_NAME=$(echo ${{ github.event.repository.name }} | tr '[:upper:]' '[:lower:]')
+        GHCR_IMAGE=ghcr.io/$REPO_OWNER/$REPO_NAME/$IMAGE_NAME
+
+        docker push $GHCR_IMAGE:latest
+        docker push $GHCR_IMAGE:$IMAGE_TAG