Build and push container images (#3)

Author: SlyngDK

.dockerignore

@@ -1,3 +1,8 @@
 # More info: https://docs.docker.com/engine/reference/builder/#dockerignore-file
 # Ignore build and test binaries.
-bin/
+!api/
+!cmd/
+!examples/
+!internal/
+!go.mod
+!go.sum

.github/workflows/build.yml

@@ -0,0 +1,48 @@
+name: Build
+
+on:
+  push:
+
+env:
+  IMG_REGISTRY: ghcr.io/slyngdk/
+  IMG_NAME_CONTROLLER: nodedrain
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v2
+
+      - name: Setup Go
+        uses: actions/setup-go@v5
+        with:
+          go-version-file: go.mod
+
+      - name: Login to GitHub Container Registry
+        if: github.ref == 'refs/heads/main' || github.ref_type == 'tag'
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Build image
+        id: build_image
+        run: |
+          export IMG_TAG=ci-${{ github.ref_name }}
+          if [[ "${{ github.ref_type }}" == "branch" && "${{ github.ref_name }}" == "main" ]]; then
+            export IMG_TAG=latest
+          elif [[ "${{ github.ref_type }}" == "tag" && "${{ github.ref_name }}" =~ ^v[0-9]+\.[0-9]+\.[0-9]+$ ]]; then
+            export IMG_TAG=$(echo -n "${{ github.ref_name }}" | sed 's/^v//g')
+          fi
+          echo "IMG_TAG=${IMG_TAG}" >> $GITHUB_OUTPUT
+          make docker-build
+
+      - name: Push image
+        if: github.ref == 'refs/heads/main' || github.ref_type == 'tag'
+        env:
+          IMG_TAG: ${{ steps.build_image.outputs.IMG_TAG }}
+        run: |
+          if [[ "${{ github.ref_type }}" == "tag" && "${{ github.ref_name }}" =~ ^v[0-9]+\.[0-9]+\.[0-9]+$ ]] || exit 0
+          make docker-push