Automatically build and push multiarch docker images on Release (#697)

* Update dockerfile to support multi-arch

* GHA release docker

* Pin docker action versions and remove permissions

* Update release-docker-images.yml

Use rwynn/monstache instead of my copy :)

* Pin docker buildx and buildkit versions

.github/workflows/release-docker-images.yml

@@ -0,0 +1,48 @@
+name: Monstache release docker images
+
+on:
+  release:
+    types: [created]
+
+  # Allows you to run this workflow manually from the Actions tab
+  workflow_dispatch:
+
+jobs:
+  docker:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+      - name: Docker meta
+        id: meta
+        uses: docker/metadata-action@818d4b7b91585d195f67373fd9cb0332e31a7175
+        with:
+          # list of Docker images to use as base name for tags
+          images: |
+            rwynn/monstache
+          # generate Docker tags based on the following events/attributes
+          tags: |
+            type=raw,value=rel6
+            type=semver,pattern={{version}}
+            type=semver,pattern={{major}}.{{minor}}
+            type=semver,pattern={{major}}
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@2b82ce82d56a2a04d2637cd93a637ae1b359c0a7
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@885d1462b80bc1c1c7f0b00334ad271f09369c55
+        with:
+          version: v0.11.2
+          driver-opts: image=moby/buildkit:v0.12.2
+      - name: Login to Docker Hub
+        uses: docker/login-action@465a07811f14bebb1938fbed4728c6a1ff8901fc
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+      - name: Build and push
+        uses: docker/build-push-action@0a97817b6ade9f46837855d676c4cca3a2471fc9
+        with:
+          context: .
+          platforms: linux/amd64,linux/arm64
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}

Dockerfile

@@ -1,25 +1,13 @@
-####################################################################################################
-# Step 1: Build the app
-####################################################################################################
-
-FROM rwynn/monstache-builder-cache-rel6:1.0.8 AS build-app
-
-RUN mkdir /app
-
-WORKDIR /app
-
-COPY . .
-
-RUN go mod download
-
-RUN make release
-
-####################################################################################################
-# Step 2: Copy output build file to an alpine image
-####################################################################################################
-
-FROM rwynn/monstache-alpine:3.17.3
-
+FROM --platform=$BUILDPLATFORM golang:1.20.4-alpine3.17 AS build
+WORKDIR /src
+ARG TARGETOS TARGETARCH
+RUN --mount=target=. \
+    --mount=type=cache,target=/root/.cache/go-build \
+    --mount=type=cache,target=/go/pkg \
+	go mod download; \
+    GOOS=$TARGETOS GOARCH=$TARGETARCH go build -o /out/monstache .
+
+FROM alpine:3.17
+RUN apk --no-cache add ca-certificates
 ENTRYPOINT ["/bin/monstache"]
-
-COPY --from=build-app /app/build/linux-amd64/monstache /bin/monstache
+COPY --from=build /out/monstache /bin