Use native platform to fetch sources, generate buildroot, etc

When building for a non-native platform (typically under qemu), use the
native platform for most operations that do not need platform specific
things, such as applying patches, tarring up sources, and fetching
go module deps.

Signed-off-by: Brian Goff <[email protected]>

Author: cpuguy83

frontend/azlinux/handle_container.go

@@ -25,7 +25,7 @@ func handleContainer(w worker) gwclient.BuildFunc {
 
 			pg := dalec.ProgressGroup("Building " + targetKey + " container: " + spec.Name)
 
-			rpmDir, err := specToRpmLLB(ctx, w, client, spec, sOpt, targetKey, pg, dalec.WithPlatform(platform))
+			rpmDir, err := buildOutputRPM(ctx, w, client, spec, sOpt, targetKey, platform, pg)
 			if err != nil {
 				return nil, nil, fmt.Errorf("error creating rpm: %w", err)
 			}

frontend/azlinux/handle_depsonly.go

@@ -36,7 +36,7 @@ func handleDepsOnly(w worker) gwclient.BuildFunc {
 				return nil, nil, err
 			}
 
-			st, err := specToContainerLLB(w, spec, targetKey, rpmDir, files, sOpt, pg)
+			st, err := specToContainerLLB(w, spec, targetKey, rpmDir, files, sOpt, pg, dalec.WithPlatform(platform))
 			if err != nil {
 				return nil, nil, err
 			}

frontend/azlinux/handle_rpm.go

@@ -11,6 +11,7 @@ import (
 	"github.com/moby/buildkit/client/llb"
 	gwclient "github.com/moby/buildkit/frontend/gateway/client"
 	ocispecs "github.com/opencontainers/image-spec/specs-go/v1"
+	"github.com/pkg/errors"
 )
 
 func handleRPM(w worker) gwclient.BuildFunc {
@@ -26,7 +27,7 @@ func handleRPM(w worker) gwclient.BuildFunc {
 				return nil, nil, err
 			}
 
-			st, err := specToRpmLLB(ctx, w, client, spec, sOpt, targetKey, pg, dalec.WithPlatform(platform))
+			st, err := buildOutputRPM(ctx, w, client, spec, sOpt, targetKey, platform, pg)
 			if err != nil {
 				return nil, nil, err
 			}
@@ -53,7 +54,7 @@ func handleRPM(w worker) gwclient.BuildFunc {
 }
 
 // Creates and installs an rpm meta-package that requires the passed in deps as runtime-dependencies
-func installBuildDepsPackage(target string, packageName string, w worker, deps map[string]dalec.PackageConstraints, installOpts ...installOpt) installFunc {
+func installBuildDepsPackage(target string, packageName string, w worker, sOpt dalec.SourceOpts, deps map[string]dalec.PackageConstraints, platform *ocispecs.Platform, installOpts ...installOpt) installFunc {
 	// depsOnly is a simple dalec spec that only includes build dependencies and their constraints
 	depsOnly := dalec.Spec{
 		Name:        fmt.Sprintf("%s-build-dependencies", packageName),
@@ -66,11 +67,11 @@ func installBuildDepsPackage(target string, packageName string, w worker, deps m
 		},
 	}
 
-	return func(ctx context.Context, client gwclient.Client, sOpt dalec.SourceOpts) (llb.RunOption, error) {
+	return func(ctx context.Context, Opt dalec.SourceOpts) (llb.RunOption, error) {
 		pg := dalec.ProgressGroup("Building container for build dependencies")
 
 		// create an RPM with just the build dependencies, using our same base worker
-		rpmDir, err := specToRpmLLB(ctx, w, client, &depsOnly, sOpt, target, pg)
+		rpmDir, err := createRPM(ctx, w, sOpt, &depsOnly, target, platform, pg)
 		if err != nil {
 			return nil, err
 		}
@@ -91,20 +92,15 @@ func installBuildDepsPackage(target string, packageName string, w worker, deps m
 	}
 }
 
-func installBuildDeps(ctx context.Context, w worker, client gwclient.Client, spec *dalec.Spec, targetKey string, opts ...llb.ConstraintsOpt) (llb.StateOption, error) {
+func installBuildDeps(ctx context.Context, w worker, sOpt dalec.SourceOpts, spec *dalec.Spec, targetKey string, platform *ocispecs.Platform, opts ...llb.ConstraintsOpt) (llb.StateOption, error) {
 	deps := spec.GetBuildDeps(targetKey)
 	if len(deps) == 0 {
 		return func(in llb.State) llb.State { return in }, nil
 	}
 
-	sOpt, err := frontend.SourceOptFromClient(ctx, client)
-	if err != nil {
-		return nil, err
-	}
-
 	opts = append(opts, dalec.ProgressGroup("Install build deps"))
 
-	installOpt, err := installBuildDepsPackage(targetKey, spec.Name, w, deps, installWithConstraints(opts))(ctx, client, sOpt)
+	installOpt, err := installBuildDepsPackage(targetKey, spec.Name, w, sOpt, deps, platform, installWithConstraints(opts))(ctx, sOpt)
 	if err != nil {
 		return nil, err
 	}
@@ -114,24 +110,58 @@ func installBuildDeps(ctx context.Context, w worker, client gwclient.Client, spe
 	}, nil
 }
 
-func specToRpmLLB(ctx context.Context, w worker, client gwclient.Client, spec *dalec.Spec, sOpt dalec.SourceOpts, targetKey string, opts ...llb.ConstraintsOpt) (llb.State, error) {
-	base, err := w.Base(sOpt, opts...)
+func createBuildroot(ctx context.Context, w worker, sOpt dalec.SourceOpts, spec *dalec.Spec, targetKey string, opts ...llb.ConstraintsOpt) (llb.State, error) {
+	opts = append(opts, dalec.ProgressGroup("Prepare rpm build root"))
+
+	// Always generate the build root usign the native platform
+	// There is nothing it does that should require the requested target platform
+	native, err := w.Base(sOpt, opts...)
 	if err != nil {
 		return llb.Scratch(), err
 	}
 
-	installOpt, err := installBuildDeps(ctx, w, client, spec, targetKey, opts...)
+	if spec.HasGomods() {
+		// Since the spec has go mods in it, we need to make sure we have go
+		// installed in the image.
+		nativeInstallDeps, err := installBuildDeps(ctx, w, sOpt, spec, targetKey, nil, opts...)
+		if err != nil {
+			return llb.Scratch(), err
+		}
+
+		native = native.With(nativeInstallDeps)
+	}
+
+	return rpm.SpecToBuildrootLLB(native, spec, sOpt, targetKey, opts...)
+}
+
+func createRPM(ctx context.Context, w worker, sOpt dalec.SourceOpts, spec *dalec.Spec, targetKey string, platform *ocispecs.Platform, opts ...llb.ConstraintsOpt) (llb.State, error) {
+	br, err := createBuildroot(ctx, w, sOpt, spec, targetKey, opts...)
+	if err != nil {
+		return llb.Scratch(), errors.Wrap(err, "error creating rpm build root")
+	}
+
+	specPath := filepath.Join("SPECS", spec.Name, spec.Name+".spec")
+
+	// Build the RPM with the target platform
+	opts = append(opts, dalec.WithPlatform(platform))
+	base, err := w.Base(sOpt, opts...)
 	if err != nil {
 		return llb.Scratch(), err
 	}
-	base = base.With(installOpt)
 
-	br, err := rpm.SpecToBuildrootLLB(base, spec, sOpt, targetKey, opts...)
+	installDeps, err := installBuildDeps(ctx, w, sOpt, spec, targetKey, platform, opts...)
 	if err != nil {
 		return llb.Scratch(), err
 	}
-	specPath := filepath.Join("SPECS", spec.Name, spec.Name+".spec")
-	st := rpm.Build(br, base, specPath, opts...)
 
+	base = base.With(installDeps)
+	return rpm.Build(br, base, specPath, opts...), nil
+}
+
+func buildOutputRPM(ctx context.Context, w worker, client gwclient.Client, spec *dalec.Spec, sOpt dalec.SourceOpts, targetKey string, platform *ocispecs.Platform, opts ...llb.ConstraintsOpt) (llb.State, error) {
+	st, err := createRPM(ctx, w, sOpt, spec, targetKey, platform, opts...)
+	if err != nil {
+		return llb.Scratch(), err
+	}
 	return frontend.MaybeSign(ctx, client, st, spec, targetKey, sOpt)
 }

frontend/azlinux/handler.go

@@ -18,7 +18,7 @@ const (
 	tdnfCacheDir = "/var/cache/tdnf"
 )
 
-type installFunc func(context.Context, gwclient.Client, dalec.SourceOpts) (llb.RunOption, error)
+type installFunc func(context.Context, dalec.SourceOpts) (llb.RunOption, error)
 
 type worker interface {
 	Base(sOpt dalec.SourceOpts, opts ...llb.ConstraintsOpt) (llb.State, error)
@@ -62,12 +62,12 @@ func handleDebug(w worker) gwclient.BuildFunc {
 		if err != nil {
 			return nil, err
 		}
-		return rpm.HandleDebug(getSpecWorker(ctx, w, client, sOpt))(ctx, client)
+		return rpm.HandleDebug(getSpecWorker(ctx, w, sOpt))(ctx, client)
 	}
 }
 
-func getSpecWorker(ctx context.Context, w worker, client gwclient.Client, sOpt dalec.SourceOpts) rpm.WorkerFunc {
-	return func(resolver llb.ImageMetaResolver, spec *dalec.Spec, targetKey string, opts ...llb.ConstraintsOpt) (llb.State, error) {
+func getSpecWorker(ctx context.Context, w worker, sOpt dalec.SourceOpts) rpm.WorkerFunc {
+	return func(resolver llb.ImageMetaResolver, spec *dalec.Spec, targetKey string, platform *ocispecs.Platform, opts ...llb.ConstraintsOpt) (llb.State, error) {
 		st, err := w.Base(sOpt, opts...)
 		if err != nil {
 			return llb.Scratch(), err
@@ -83,7 +83,7 @@ func getSpecWorker(ctx context.Context, w worker, client gwclient.Client, sOpt d
 				return llb.Scratch(), errors.New("spec contains go modules but does not have golang in build deps")
 			}
 
-			installOpt, err := installBuildDeps(ctx, w, client, spec, targetKey, opts...)
+			installOpt, err := installBuildDeps(ctx, w, sOpt, spec, targetKey, platform, opts...)
 			if err != nil {
 				return llb.Scratch(), err
 			}

frontend/rpm/handle_buildroot.go

@@ -11,7 +11,7 @@ import (
 	ocispecs "github.com/opencontainers/image-spec/specs-go/v1"
 )
 
-type WorkerFunc func(resolver llb.ImageMetaResolver, spec *dalec.Spec, targetKey string, opts ...llb.ConstraintsOpt) (llb.State, error)
+type WorkerFunc func(resolver llb.ImageMetaResolver, spec *dalec.Spec, targetKey string, platform *ocispecs.Platform, opts ...llb.ConstraintsOpt) (llb.State, error)
 
 func HandleBuildroot(wf WorkerFunc) gwclient.BuildFunc {
 	return func(ctx context.Context, client gwclient.Client) (*gwclient.Result, error) {
@@ -21,7 +21,9 @@ func HandleBuildroot(wf WorkerFunc) gwclient.BuildFunc {
 				return nil, nil, err
 			}
 
-			worker, err := wf(sOpt.Resolver, spec, targetKey)
+			// Note, we are not passing platform down here because everything should
+			// be able to work regardless of platform, so prefer the native platform.
+			worker, err := wf(sOpt.Resolver, spec, targetKey, platform)
 			if err != nil {
 				return nil, nil, err
 			}

frontend/rpm/handle_sources.go

@@ -21,11 +21,13 @@ func HandleSources(wf WorkerFunc) gwclient.BuildFunc {
 				return nil, nil, err
 			}
 
-			worker, err := wf(sOpt.Resolver, spec, targetKey)
+			worker, err := wf(sOpt.Resolver, spec, targetKey, platform)
 			if err != nil {
 				return nil, nil, err
 			}
 
+			// Note, we are not passing platform down here because everything should
+			// be able to work regardless of platform, so prefer the native platform.
 			sources, err := Dalec2SourcesLLB(worker, spec, sOpt)
 			if err != nil {
 				return nil, nil, err