Add container build workflow

Author: tpoliaw

.github/workflows/publish.yaml

@@ -2,8 +2,43 @@ name: Image Publishing
 
 on:
   push:
+    # Run only on release pushes
     tags:
       - v*
+  # but all PRs
+  pull_request:
 
 jobs:
   build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Build image
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          cache-from: type=gha
+          cache-to: type=gha
+          tags: ci_test
+
+      - name: Login to GHCR
+        if: ${{ github.event_name == 'push' && github.ref_type == 'tag' }}
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io/${{ github.repository_owner }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Publish image
+        if: ${{ github.event_name == 'push' && github.ref_type == 'tag' }}
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          tags: ${{ github.ref_name }}
+          cache-from: type=gha
+          push: true