Make fork-name optional in fork command

Signed-off-by: Joffrey F <joffrey@docker.com>

Author: shin-

cmd/docker-app/fork.go

@@ -13,11 +13,15 @@ var (
 
 func forkCmd() *cobra.Command {
 	cmd := &cobra.Command{
-		Use:   "fork <origin-name> <fork-name> [-p outputdir] [-m name:email ...]",
+		Use:   "fork <origin-name> [fork-name] [-p outputdir] [-m name:email ...]",
 		Short: "Create a fork of an existing application to be modified",
-		Args:  cli.ExactArgs(2),
+		Args:  cli.RequiresRangeArgs(1, 2),
 		RunE: func(cmd *cobra.Command, args []string) error {
-			return packager.Fork(args[0], args[1], outputDir, forkMaintainers)
+			forkName := ""
+			if len(args) >= 2 {
+				forkName = args[1]
+			}
+			return packager.Fork(args[0], forkName, outputDir, forkMaintainers)
 		},
 	}
 	cmd.Flags().StringArrayVarP(&forkMaintainers, "maintainer", "m", []string{}, "Maintainer (name:email) (optional)")

e2e/commands_test.go

@@ -12,8 +12,6 @@ import (
 	"testing"
 
 	"github.com/docker/app/internal"
-	"github.com/docker/app/internal/types"
-	yaml "gopkg.in/yaml.v2"
 
 	"gotest.tools/assert"
 	"gotest.tools/fs"
@@ -332,29 +330,10 @@ func TestForkBinary(t *testing.T) {
 	assert.NilError(t, err)
 
 	golden.Assert(t, string(metadata), "expected-fork-metadata.golden")
-	var decodedMeta types.AppMetadata
-	err = yaml.Unmarshal(metadata, &decodedMeta)
+
+	assertCommand(t, dockerApp, "fork", registry+"/acmecorp/simple.dockerapp:1.1.0-beta1", "-p", tempDir, "-m", "Remilia Scarlet:remilia@acmecorp.cool")
+	metadata2, err := ioutil.ReadFile(filepath.Join(tempDir, "simple.dockerapp", "metadata.yml"))
 	assert.NilError(t, err)
-	var expected = types.AppMetadata{
-		Name:        "scarlet.devil",
-		Namespace:   "acmecorp",
-		Version:     "1.1.0-beta1",
-		Description: "new fancy webapp with microservices",
-		Maintainers: types.Maintainers{
-			{Name: "Remilia Scarlet", Email: "remilia@acmecorp.cool"},
-		},
-		Parents: types.Parents{
-			{
-				Name:      "simple",
-				Namespace: "acmecorp",
-				Version:   "1.1.0-beta1",
-				Maintainers: types.Maintainers{
-					{Name: "John Developer", Email: "john.dev@acmecorp.cool"},
-					{Name: "Jane Developer", Email: "jane.dev@acmecorp.cool"},
-				},
-			},
-		},
-	}
 
-	assert.DeepEqual(t, decodedMeta, expected)
+	golden.Assert(t, string(metadata2), "expected-fork-metadata-no-rename.golden")
 }

e2e/testdata/expected-fork-metadata-no-rename.golden

@@ -0,0 +1,16 @@
+version: 1.1.0-beta1
+name: simple
+description: new fancy webapp with microservices
+namespace: ""
+maintainers:
+- name: Remilia Scarlet
+  email: remilia@acmecorp.cool
+parents:
+- name: simple
+  namespace: acmecorp
+  version: 1.1.0-beta1
+  maintainers:
+  - name: John Developer
+    email: john.dev@acmecorp.cool
+  - name: Jane Developer
+    email: jane.dev@acmecorp.cool

internal/packager/fork.go

@@ -22,6 +22,9 @@ func Fork(originName, forkName, outputDir string, maintainers []string) error {
 	if err != nil {
 		return errors.Wrapf(err, "origin %q is not a valid image name", originName)
 	}
+	if forkName == "" {
+		forkName = internal.AppNameFromDir(imgRef.Name)
+	}
 	log.Debugf("Pulling latest version of package %s", originName)
 	if err := pullImage(originName); err != nil {
 		return err