Build backend into docker image and push to GH registry

Author: Kronos3

.github/workflows/docker.yml

@@ -0,0 +1,74 @@
+name: Build and Push Docker Image
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    paths-ignore:
+      - 'docs/**'
+      - 'README.md'
+      - 'zensical.toml'
+  release:
+    types: [published]
+  workflow_dispatch:
+
+env:
+  REGISTRY: ghcr.io
+  IMAGE_NAME: ${{ github.repository }}
+
+jobs:
+  build-and-push:
+    name: Build and Push Docker Image
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+      - name: Checkout code
+        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
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+          tags: |
+            # Tag with 'dev' on push to main
+            type=raw,value=dev,enable={{is_default_branch}}
+            # Tag with version number on release
+            type=semver,pattern={{version}}
+            # Tag with 'latest' on release (not pre-release)
+            type=raw,value=latest,enable=${{ github.event_name == 'release' && !github.event.release.prerelease }}
+          labels: |
+            org.opencontainers.image.title=Hermes Backend
+            org.opencontainers.image.description=NASA telemetry and commanding system backend
+            org.opencontainers.image.vendor=Jet Propulsion Laboratory
+
+      - name: Build and push Docker image
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          file: docker/Dockerfile
+          push: ${{ github.event_name != 'pull_request' }}
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max
+          platforms: linux/amd64,linux/arm64
+
+      - name: Image digest
+        if: github.event_name != 'pull_request'
+        run: echo "Image pushed with digest ${{ steps.meta.outputs.digest }}"