Add Dockerfile and GitHub Actions workflow for GHCR publishing

Co-authored-by: johndoe6345789 <224850594+johndoe6345789@users.noreply.github.com>

.github/workflows/docker-publish.yml

@@ -0,0 +1,111 @@
+name: Docker Build and Publish
+
+on:
+  push:
+    branches:
+      - main
+      - develop
+    tags:
+      - 'v*'
+  pull_request:
+    branches:
+      - main
+      - develop
+  workflow_dispatch:
+
+env:
+  REGISTRY: ghcr.io
+  IMAGE_NAME: ${{ github.repository }}
+
+jobs:
+  build-and-test:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Log in to GitHub Container Registry
+        if: github.event_name != 'pull_request'
+        uses: docker/login-action@v3
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Extract metadata (tags, labels) for Docker
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+          tags: |
+            type=ref,event=branch
+            type=ref,event=pr
+            type=semver,pattern={{version}}
+            type=semver,pattern={{major}}.{{minor}}
+            type=semver,pattern={{major}}
+            type=sha,prefix={{branch}}-
+            type=raw,value=latest,enable={{is_default_branch}}
+
+      - name: Build Docker image
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          file: ./Dockerfile
+          push: false
+          load: true
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max
+
+      - name: Test Docker image
+        run: |
+          echo "Testing SparkOS Docker image..."
+          # Get the first tag from the metadata output
+          IMAGE_TAG=$(echo "${{ steps.meta.outputs.tags }}" | head -n1)
+          echo "Using image: $IMAGE_TAG"
+          
+          # Run the container and check output
+          docker run --rm "$IMAGE_TAG"
+          
+          # Verify init binary exists and is executable
+          docker run --rm "$IMAGE_TAG" sh -c "test -x /sparkos/rootfs/sbin/init && echo 'Init binary is executable'"
+          
+          echo "Docker image test completed successfully!"
+
+      - name: Push Docker image to GHCR
+        if: github.event_name != 'pull_request'
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          file: ./Dockerfile
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max
+
+      - name: Output image details
+        if: github.event_name != 'pull_request'
+        run: |
+          echo "### Docker Image Published! 🐳" >> $GITHUB_STEP_SUMMARY
+          echo "" >> $GITHUB_STEP_SUMMARY
+          echo "**Registry:** ${{ env.REGISTRY }}" >> $GITHUB_STEP_SUMMARY
+          echo "**Repository:** ${{ env.IMAGE_NAME }}" >> $GITHUB_STEP_SUMMARY
+          echo "" >> $GITHUB_STEP_SUMMARY
+          echo "**Tags:**" >> $GITHUB_STEP_SUMMARY
+          echo '```' >> $GITHUB_STEP_SUMMARY
+          echo "${{ steps.meta.outputs.tags }}" >> $GITHUB_STEP_SUMMARY
+          echo '```' >> $GITHUB_STEP_SUMMARY
+          echo "" >> $GITHUB_STEP_SUMMARY
+          echo "**Pull command:**" >> $GITHUB_STEP_SUMMARY
+          echo '```bash' >> $GITHUB_STEP_SUMMARY
+          echo "docker pull ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:latest" >> $GITHUB_STEP_SUMMARY
+          echo '```' >> $GITHUB_STEP_SUMMARY