feat: add GitHub Actions workflow for building and publishing Docker images (#29)

Author: CasLubbers

.github/workflows/build-and-push.yml

@@ -0,0 +1,40 @@
+name: Build and publish Docker
+
+on:
+  push:
+    branches:
+      - '**'
+    tags:
+      - 'v*'
+  workflow_dispatch:
+    inputs:
+      dry-run:
+        description: 'Skip pushing built images'
+        type: boolean
+        default: true
+env:
+  IMAGE_NAME: linode/apl-nodejs-helloworld
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v6
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Log in to Docker registry
+        uses: docker/login-action@v3
+        with:
+          username: ${{ vars.DOCKER_USERNAME }}
+          password: ${{ secrets.DOCKER_PASSWORD }}
+
+      - name: CI tests, image build and push tag for main or branch
+        uses: docker/build-push-action@v6
+        with:
+          push: ${{ github.event_name == 'push' || !github.event.inputs.dry-run }}
+          context: .
+          tags: |
+            ${{ env.IMAGE_NAME }}:${{ github.ref_name }}