Tidy up some of the YAML

Signed-off-by: Adrian Mouat <adrian@chainguard.dev>

.github/workflows/build-and-push-cross.yaml

@@ -30,6 +30,7 @@ jobs:
         name: Build and push
         uses: docker/build-push-action@v6
         with:
+          file: cross.Dockerfile
           platforms: linux/amd64,linux/arm64
           push: true
           tags: amouat/images-bite-back:latest

.github/workflows/build-and-push.yaml

@@ -14,9 +14,6 @@ jobs:
   docker:
     runs-on: ubuntu-latest
     steps:
-      -
-        name: Set up QEMU
-        uses: docker/setup-qemu-action@v3
       -
         name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
@@ -36,7 +33,8 @@ jobs:
         name: Build and push
         uses: docker/build-push-action@v6
         with:
-          platforms: linux/amd64,linux/arm64
+          file: Dockerfile
+          platforms: linux/amd64
           push: true
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}

Dockerfile

@@ -7,11 +7,9 @@ COPY go.mod /work/
 COPY cmd /work/cmd
 COPY internal /work/internal
 
-# See https://mt165.co.uk/blog/static-link-go/ for creating static binaries
 RUN CGO_ENABLED=0 go build -o hello ./cmd/server
 
 FROM cgr.dev/chainguard/static
-COPY --from=builder /work/hello /hello 
-
-ENTRYPOINT ["/hello"]
+COPY --from=builder /work/hello /hello
 
+ENTRYPOINT ["/hello"]

cross-xx.Dockerfile

@@ -1,3 +1,4 @@
+# syntax=docker/dockerfile:1
 # Load cross-platform helper functions
 FROM --platform=$BUILDPLATFORM tonistiigi/xx AS xx
 
@@ -12,7 +13,6 @@ COPY go.mod /work/
 COPY cmd /work/cmd
 COPY internal /work/internal
 
-# See https://mt165.co.uk/blog/static-link-go/ for creating static binaries
 #RUN GOOS=${TARGETOS} GOARCH=${TARGETARCH} CGO_ENABLED=0 go build -o hello ./cmd/server
 RUN CGO_ENABLED=0 xx-go build -o hello ./cmd/server
 

cross.Dockerfile

@@ -1,3 +1,4 @@
+# syntax=docker/dockerfile:1
 FROM --platform=$BUILDPLATFORM cgr.dev/chainguard/go:latest-dev AS builder
 ARG TARGETOS
 ARG TARGETARCH
@@ -7,7 +8,6 @@ COPY go.mod /work/
 COPY cmd /work/cmd
 COPY internal /work/internal
 
-# See https://mt165.co.uk/blog/static-link-go/ for creating static binaries
 RUN GOOS=${TARGETOS} GOARCH=${TARGETARCH} CGO_ENABLED=0 go build -o hello ./cmd/server
 
 FROM cgr.dev/chainguard/static