feat: allow symlink

pkg/commands/options/filestuff.go

@@ -59,6 +59,11 @@ func EnumerateFiles(fo *FilenameOptions) chan string {
 				// processing (unless we are in recursive mode).  If we decide to process
 				// the directory, and we're in watch mode, then we set up a watch on the
 				// directory.
+				symlink, err := ResolveSymlink(path, fi)
+				if err != nil {
+					return err
+				}
+
 				if fi.IsDir() {
 					if path != paths && !fo.Recursive {
 						return filepath.SkipDir
@@ -67,6 +72,10 @@ func EnumerateFiles(fo *FilenameOptions) chan string {
 					return nil
 				}
 
+				if symlink != "" {
+					files <- symlink
+				}
+
 				// Don't check extension if the filepath was passed explicitly
 				if path != paths {
 					switch filepath.Ext(path) {
@@ -87,3 +96,13 @@ func EnumerateFiles(fo *FilenameOptions) chan string {
 	}()
 	return files
 }
+
+func ResolveSymlink(path string, fi os.FileInfo) (symlink string, err error) {
+	if fi.Mode()&os.ModeSymlink == os.ModeSymlink {
+		symlink, err = os.Readlink(path) // TODO: Handle error here
+		if !filepath.IsAbs(symlink) {    // Output of os.Readlink is OS-dependent...
+			symlink = filepath.Join(filepath.Dir(path), symlink)
+		}
+	}
+	return
+}

pkg/commands/resolver.go

@@ -405,7 +405,25 @@ func resolveFile(
 	if f == "-" {
 		b, err = ioutil.ReadAll(os.Stdin)
 	} else {
-		b, err = ioutil.ReadFile(f)
+		fi, err := os.Lstat(f)
+		if err != nil {
+			return nil, fmt.Errorf("unable to find file %s selector: %wß", f, err)
+		}
+
+		symlink, err := options.ResolveSymlink(f, fi)
+		if err != nil {
+			return nil, fmt.Errorf("unable to resolve symlink of file %s selector: %w", f, err)
+		}
+
+		if symlink != "" {
+			b, err = ioutil.ReadFile(symlink)
+		} else {
+			b, err = ioutil.ReadFile(f)
+		}
+
+		if err != nil {
+			return nil, fmt.Errorf("unable to read file %s: %w", f, err)
+		}
 	}
 	if err != nil {
 		return nil, err

pkg/commands/resolver_test.go

@@ -25,10 +25,15 @@ import (
 	"io/ioutil"
 	"log"
 	"net/http/httptest"
+	"os"
 	"path"
+	"path/filepath"
+	"runtime"
 	"strings"
 	"testing"
 
+	"gopkg.in/yaml.v3"
+
 	"github.com/docker/docker/api/types"
 	"github.com/google/go-cmp/cmp"
 	"github.com/google/go-cmp/cmp/cmpopts"
@@ -42,7 +47,6 @@ import (
 	"github.com/google/ko/pkg/build"
 	"github.com/google/ko/pkg/commands/options"
 	kotesting "github.com/google/ko/pkg/internal/testing"
-	"gopkg.in/yaml.v3"
 )
 
 var (
@@ -65,6 +69,12 @@ var (
 	errImageTag  = fmt.Errorf("ImageTag() error")
 )
 
+func RootDir() string {
+	_, b, _, _ := runtime.Caller(0)
+	d := path.Join(path.Dir(b), "..")
+	return filepath.Dir(d)
+}
+
 type erroringClient struct {
 	daemon.Client
 }
@@ -131,6 +141,62 @@ func TestResolveMultiDocumentYAMLs(t *testing.T) {
 	}
 }
 
+func TestResolveSymlink(t *testing.T) {
+	testRef := "github.com/google/ko/test"
+	refs := []string{testRef}
+	hashes := []v1.Hash{fooHash}
+
+	f := filepath.Join(RootDir(), "test", "test.yaml")
+	inputYAML, err := os.ReadFile(f)
+	if err != nil {
+		t.Fatalf("Readfile(%s) = %v", f, err)
+	}
+
+	m := map[string]v1.Hash{
+		testRef: fooHash,
+	}
+
+	base := mustRepository("gcr.io/multi-pass")
+	outYAML, err := resolveFile(
+		context.Background(),
+		filepath.Join(RootDir(), "test", "symlink.yaml"),
+		kotesting.NewFixedBuild(map[string]build.Result{
+			testRef: foo,
+		}),
+		kotesting.NewFixedPublish(base, m),
+		&options.SelectorOptions{})
+
+	if err != nil {
+		t.Fatalf("ImageReferences(%v) = %v", string(inputYAML), err)
+	}
+
+	rd := bytes.NewReader(outYAML)
+	decoder := yaml.NewDecoder(rd)
+	var outStructured []string
+	for {
+		var output map[string]interface{}
+		if err := decoder.Decode(&output); err == nil {
+			outStructured = append(outStructured, output["spec"].(map[string]interface{})["containers"].([]interface{})[0].(map[string]interface{})["image"].(string))
+		} else if errors.Is(err, io.EOF) {
+			break
+		} else {
+			t.Errorf("yaml.Unmarshal(%v) = %v", string(outYAML), err)
+		}
+	}
+
+	expectedStructured := []string{
+		kotesting.ComputeDigest(base, refs[0], hashes[0]),
+	}
+
+	if want, got := len(expectedStructured), len(outStructured); want != got {
+		t.Errorf("resolveFile(%v) = %v, want %v", string(inputYAML), got, want)
+	}
+
+	if diff := cmp.Diff(expectedStructured, outStructured, cmpopts.EquateEmpty()); diff != "" {
+		t.Errorf("resolveFile(%v); (-want +got) = %v", string(inputYAML), diff)
+	}
+}
+
 func TestResolveMultiDocumentYAMLsWithSelector(t *testing.T) {
 	passesSelector := `apiVersion: something/v1
 kind: Foo

test/symlink.yaml

@@ -0,0 +1 @@
+test.yaml