Add a container building workflow

Author: QuLogic

.github/workflows/build-image.yml

@@ -0,0 +1,46 @@
+---
+
+name: Create and publish a container image
+
+on:
+  push
+
+env:
+  REGISTRY: ghcr.io
+  IMAGE_NAME: ${{ github.repository }}
+  CADDY_VERSION: "2.4.6"
+
+jobs:
+  build-and-push-image:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v2
+
+      - name: Log in to the Container registry
+        uses: docker/login-action@v1.12.0
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Extract metadata (tags, labels)
+        id: meta
+        uses: docker/metadata-action@v3.6.2
+        with:
+          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+
+      - name: Build and push container image
+        uses: docker/build-push-action@v2.9.0
+        with:
+          context: .
+          file: ./Containerfile
+          build-args: |
+            CADDY_VERSION=${{ env.CADDY_VERSION }}
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}

Containerfile

@@ -0,0 +1,8 @@
+ARG CADDY_VERSION=latest
+FROM docker.io/library/caddy:${CADDY_VERSION}-builder AS builder
+
+RUN xcaddy build
+
+FROM docker.io/library/caddy:${CADDY_VERSION}
+
+COPY --from=builder /usr/bin/caddy /usr/bin/caddy

Makefile

@@ -1,4 +1,5 @@
 RUNTIME ?= podman
+CADDY_IMAGE ?= caddy-mpl
 CADDY_VERSION ?= 2.4.6
 
 serve:
@@ -8,11 +9,17 @@ serve:
 	    -v $$PWD/Caddyfile:/etc/caddy/Caddyfile:ro,Z \
 	    -e SITE_DIR=/srv \
 	    -p 2015:2015 \
-	    docker.io/library/caddy:$(CADDY_VERSION) \
+	    $(CADDY_IMAGE):$(CADDY_VERSION) \
 	    caddy run --config /etc/caddy/Caddyfile --watch
 
+image:
+	$(RUNTIME) build \
+	    --build-arg=CADDY_VERSION=$(CADDY_VERSION) \
+	    -t $(CADDY_IMAGE):$(CADDY_VERSION) \
+	    -f Containerfile
+
 fmt:
 	$(RUNTIME) run --rm -it \
 	    -v $$PWD/Caddyfile:/etc/caddy/Caddyfile:Z \
-	    docker.io/library/caddy:$(CADDY_VERSION) \
+	    $(CADDY_IMAGE):$(CADDY_VERSION) \
 	    caddy fmt --overwrite /etc/caddy/Caddyfile