Fix image resolution pipeline

- pass the user specified image in the resolve request
- default to linux/arm64 for cross platform builds

Author: wlan0

Makefile

@@ -43,7 +43,7 @@ build: $(BUILD_DIR)
 
 .PHONY: build-linux
 build-linux: $(BUILD_DIR)
-	CGO_ENABLED=0 GOOS=linux GOARCH=amd64 $(GO) build $(GOFLAGS) -o $(BUILD_DIR)/$(BINARY_NAME)-linux .
+	CGO_ENABLED=0 GOOS=linux GOARCH=arm64 $(GO) build $(GOFLAGS) -o $(BUILD_DIR)/$(BINARY_NAME)-linux .
 
 .PHONY: fmt
 fmt:	go-fmt update-licenses

pkg/build/frontend.go

@@ -165,7 +165,7 @@ func resolveStates(ctx context.Context, bopts *BOpts, platform ocispecs.Platform
 			resolverOpts.ImageOpt = &sourceresolver.ResolveImageOpt{
 				ResolveMode: llb.ResolveModePreferLocal.String(),
 			}
-			_, digest, img, err := bopts.Resolver.ResolveImageConfig(ctx, ref.String(), resolverOpts)
+			_, digest, img, err := bopts.Resolver.ResolveImageConfig(ctx, resolvedBaseStageName.Result, resolverOpts)
 			if err != nil {
 				if err == reference.ErrObjectRequired {
 					return

pkg/resolver/resolver.go

@@ -21,12 +21,10 @@ import (
 	"fmt"
 
 	"github.com/containerd/containerd/platforms"
-	"github.com/containerd/containerd/reference"
 	"github.com/google/uuid"
 	"github.com/moby/buildkit/client/llb"
 	"github.com/moby/buildkit/client/llb/sourceresolver"
 	"github.com/opencontainers/go-digest"
-	"github.com/sirupsen/logrus"
 
 	"github.com/apple/container-builder-shim/pkg/api"
 	"github.com/apple/container-builder-shim/pkg/stream"
@@ -119,14 +117,6 @@ Response Format:
 */
 func (r *ResolverProxy) ResolveImageConfig(ctx context.Context, ref string, opt sourceresolver.Opt) (string, digest.Digest, []byte, error) {
 	var err error
-	u, err := reference.Parse(ref)
-	if err != nil {
-		logrus.Debugf("reference parse error: %v", err)
-		return ref, digest.Digest(""), nil, err
-	} else if u.Object == "" {
-		logrus.Debugf("reference object empty: %#v", u)
-		return ref, digest.Digest(""), nil, reference.ErrObjectRequired
-	}
 
 	req := &api.ImageTransfer{
 		Direction: api.TransferDirection_INTO,

pkg/resolver/resolver_test.go

@@ -104,13 +104,3 @@ func TestResolverProxy_ResolveImageConfig_ErrorMetadata(t *testing.T) {
 		t.Fatalf("expected error from metadata, got nil")
 	}
 }
-
-func TestResolverProxy_ResolveImageConfig_InvalidReference(t *testing.T) {
-	proxy := NewResolverProxy()
-	plt := platforms.DefaultSpec()
-	badRef := "justarepo"
-	_, _, _, err := proxy.ResolveImageConfig(context.Background(), badRef, sourceresolver.Opt{Platform: &plt})
-	if err == nil {
-		t.Fatalf("expected reference parse error, got nil")
-	}
-}