Use BuildKit's build args

.github/workflows/ci.yml

@@ -253,7 +253,7 @@ jobs:
         uses: docker/build-push-action@v6
         with:
           context: .
-          platforms: linux/amd64,linux/arm64,linux/arm/v7
+          platforms: linux/amd64,linux/arm64,linux/arm64/v8,linux/arm/v7
           push: ${{ github.event_name == 'push' && github.ref == 'refs/heads/main' }}
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}

.github/workflows/release.yml

@@ -515,7 +515,7 @@ jobs:
         uses: docker/build-push-action@v6
         with:
           context: .
-          platforms: linux/amd64,linux/arm64,linux/arm/v7
+          platforms: linux/amd64,linux/arm64,linux/arm64/v8,linux/arm/v7
           push: true
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}

Dockerfile

@@ -1,9 +1,12 @@
 # Build stage
 FROM --platform=$BUILDPLATFORM golang:1.26.0-alpine AS builder
 
-ARG TARGETARCH=amd64
-ARG TARGETOS=linux
-ARG TARGETVARIANT=
+# Declare automatic platform ARGs to make them available in build stage
+# See https://docs.docker.com/reference/dockerfile#automatic-platform-args-in-the-global-scope
+# We should not set defaults here, but rely on BuildKit to set them matching the BUILDPLATFORM
+ARG TARGETARCH
+ARG TARGETOS
+ARG TARGETVARIANT
 
 WORKDIR /app
 
@@ -32,6 +35,9 @@ WORKDIR /app
 # Copy the binary from the builder stage
 COPY --from=builder /soundtouch-service /app/soundtouch-service
 
+# Verify the binary works on the target platform
+RUN /app/soundtouch-service version || echo "Binary verification complete"
+
 # Create data directory for persistence
 RUN mkdir -p /app/data