add docker build action

.github/workflows/docker.yml

@@ -0,0 +1,73 @@
+name: docker-build
+
+on:
+  pull_request:
+    branches:
+      - main
+  push:
+    branches:
+      - main
+    tags:
+      - 'v*'
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      # https://docs.docker.com/build/ci/github-actions/multi-platform/
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v2
+
+      # Workaround: https://github.com/docker/build-push-action/issues/461
+      - name: Setup Docker buildx
+        uses: docker/setup-buildx-action@v2
+
+      - name: Log in to the github container registry
+        uses: docker/login-action@v2
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+
+      # https://github.com/docker/login-action
+      - name: Login to DockerHub
+        uses: docker/login-action@v2
+        with:
+          username: ${{ secrets.DOCKERHUB_USER }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+
+      - name: Extract metadata (tags, labels) for Docker
+        id: meta
+        uses: docker/metadata-action@v4
+        with:
+
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          images: |
+            ghcr.io/${{ github.repository }}
+            terraformlabs/localterra
+          tags: |
+            type=sha
+            type=edge,branch=test
+            type=semver,pattern={{tag}}
+            type=semver,pattern={{version}}
+            type=raw,value=latest,event=branch,enable=${{ github.ref == format('refs/heads/{0}', 'main') }}
+            type=raw,value=classic,event=branch,enable=${{ github.ref == format('refs/heads/{0}', 'classic') }}
+
+      - name: Build docker image
+        uses: docker/build-push-action@v3
+        with:
+          push: ${{ github.event_name != 'pull_request' }}
+          file: Dockerfile
+          platforms: linux/amd64
+          tags: ${{ env.DOCKER_METADATA_OUTPUT_TAGS }}
+          labels: ${{ env.DOCKER_METADATA_OUTPUT_LABELS }}
+
+