Address feedback

pkg/build/build.go

@@ -41,3 +41,7 @@ type Result interface {
  Digest() (v1.Hash, error)
  RawManifest() ([]byte, error)
 }
+
+// Assert that Image and ImageIndex implement Result.
+var _ Result = (v1.Image)(nil)
+var _ Result = (v1.ImageIndex)(nil)

pkg/build/gobuild.go

@@ -257,7 +257,7 @@ func build(ctx context.Context, ip string, platform v1.Platform, disableOptimiza
  cmd.Stderr = &output
  cmd.Stdout = &output
 
- log.Printf("Building %s", ip)
+ log.Printf("Building %s for %s", ip, platform.Architecture)
  if err := cmd.Run(); err != nil {
  os.RemoveAll(tmpDir)
  log.Printf("Unexpected error running \"go build\": %v\n%v", err, output.String())
@@ -593,6 +593,7 @@ func (gb *gobuild) Build(ctx context.Context, s string) (Result, error) {
  }
 }
 
+// TODO(#192): Do these in parallel?
 func (gb *gobuild) buildAll(ctx context.Context, s string, base v1.ImageIndex) (v1.ImageIndex, error) {
  im, err := base.IndexManifest()
  if err != nil {
@@ -602,7 +603,11 @@ func (gb *gobuild) buildAll(ctx context.Context, s string, base v1.ImageIndex) (
  // Build an image for each child from the base and append it to a new index to produce the result.
  adds := []mutate.IndexAddendum{}
  for _, desc := range im.Manifests {
- // TODO(jonjohnsonjr): This would fail for a nested index, which is exceedingly rare.
+ // Nested index is pretty rare. We could support this in theory, but return an error for now.
+ if desc.MediaType != types.OCIManifestSchema1 && desc.MediaType != types.DockerManifestSchema2 {
+ return nil, fmt.Errorf("%q has unexpected mediaType %q in base for %q", desc.Digest, desc.MediaType, s)
+ }
+
  base, err := base.Image(desc.Digest)
  if err != nil {
  return nil, err

pkg/build/gobuild_test.go

@@ -27,6 +27,8 @@ import (
  "time"
 
  v1 "github.com/google/go-containerregistry/pkg/v1"
+ "github.com/google/go-containerregistry/pkg/v1/empty"
+ "github.com/google/go-containerregistry/pkg/v1/mutate"
  "github.com/google/go-containerregistry/pkg/v1/random"
 )
 
@@ -500,3 +502,34 @@ func TestGoBuildIndex(t *testing.T) {
  }
  })
 }
+
+func TestNestedIndex(t *testing.T) {
+ baseLayers := int64(3)
+ images := int64(2)
+ base, err := random.Index(1024, baseLayers, images)
+ if err != nil {
+ t.Fatalf("random.Image() = %v", err)
+ }
+ importpath := "github.com/google/ko"
+
+ nestedBase := mutate.AppendManifests(empty.Index, mutate.IndexAddendum{Add: base})
+
+ creationTime := v1.Time{time.Unix(5000, 0)}
+ ng, err := NewGo(
+ WithCreationTime(creationTime),
+ WithBaseImages(func(string) (Result, error) { return nestedBase, nil }),
+ withBuilder(writeTempFile),
+ )
+ if err != nil {
+ t.Fatalf("NewGo() = %v", err)
+ }
+
+ _, err = ng.Build(context.Background(), filepath.Join(importpath, "cmd", "ko", "test"))
+ if err == nil {
+ t.Fatal("Build() expected err")
+ }
+
+ if !strings.Contains(err.Error(), "unexpected mediaType") {
+ t.Errorf("Build() expected unexpected mediaType error, got: %s", err)
+ }
+}

pkg/build/recorder.go

@@ -34,6 +34,7 @@ func (r *Recorder) IsSupportedReference(ip string) bool {
  return r.Builder.IsSupportedReference(ip)
 }
 
+// Build implements Interface
 func (r *Recorder) Build(ctx context.Context, ip string) (Result, error) {
  func() {
  r.m.Lock()

pkg/commands/config.go

@@ -20,6 +20,7 @@ import (
  "log"
  "os"
  "os/signal"
+ "path"
  "strconv"
  "strings"
  "syscall"
@@ -40,6 +41,16 @@ var (
 )
 
 func getBaseImage(platform string) build.GetBase {
+ // Default to linux/amd64 unless GOOS and GOARCH are set.
+ if platform == "" {
+ platform = "linux/amd64"
+
+ goos, goarch := os.Getenv("GOOS"), os.Getenv("GOARCH")
+ if goos != "" && goarch != "" {
+ platform = path.Join(goos, goarch)
+ }
+ }
+
  return func(s string) (build.Result, error) {
  // Viper configuration file keys are case insensitive, and are
  // returned as all lowercase. This means that import paths with
@@ -70,6 +81,9 @@ func getBaseImage(platform string) build.GetBase {
  if len(parts) > 2 {
  p.Variant = parts[2]
  }
+ if len(parts) > 3 {
+ return nil, fmt.Errorf("too many slashes in platform spec: %s", platform)
+ }
  ropt = append(ropt, remote.WithPlatform(p))
  }
 

pkg/commands/options/build.go

@@ -32,7 +32,7 @@ func AddBuildOptions(cmd *cobra.Command, bo *BuildOptions) {
  "The maximum number of concurrent builds")
  cmd.Flags().BoolVar(&bo.DisableOptimizations, "disable-optimizations", bo.DisableOptimizations,
  "Disable optimizations when building Go code. Useful when you want to interactively debug the created container.")
- cmd.Flags().StringVar(&bo.Platform, "platform", "linux/amd64",
+ cmd.Flags().StringVar(&bo.Platform, "platform", "",
  "Which platform to use when pulling a multi-platform base. Format: all | <os>[/<arch>[/<variant>]]")
 
 }