Add a docker build step.

.forgejo/workflows/docker.yml

@@ -0,0 +1,58 @@
+name: Docker Build
+
+on:
+  push:
+    branches: [ main, docker ]
+
+jobs:
+  docker-backend:
+    name: Build and Push Backend Image
+    runs-on: docker
+    steps:
+      - name: Checkout Repo
+        uses: actions/checkout@v4
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Login to Forgejo Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ${{ forgejo.server_url }}
+          username: ${{ forgejo.actor }}
+          password: ${{ secrets.FORGEJO_TOKEN }}
+
+      - name: Build and push image
+        uses: docker/build-push-action@v5
+        with:
+          context: ./backend
+          push: true
+          tags: drew/captains-log-backend
+          cache-from: type=gha
+          cache-to: type=gha,mode=max
+
+  docker-frontend:
+    name: Build and Push Frontend Image
+    runs-on: docker
+    steps:
+      - name: Checkout Repo
+        uses: actions/checkout@v4
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Login to Forgejo Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ${{ forgejo.server_url }}
+          username: ${{ forgejo.actor }}
+          password: ${{ secrets.FORGEJO_TOKEN }}
+
+      - name: Build and push image
+        uses: docker/build-push-action@v5
+        with:
+          context: ./frontend
+          push: true
+          tags: drew/captains-log-frontend
+          cache-from: type=gha
+          cache-to: type=gha,mode=max