Simplify 'kubectl edit' logic

edit: make editFn operate on arguments regardless of mode

edit: simplify short-circuiting logic when re-editing a file containing an error

edit: factor out visitor building

edit: use resource builder to get results from edited file

pkg/kubectl/cmd/edit.go

@@ -131,7 +131,7 @@ func runEdit(f cmdutil.Factory, out, errOut io.Writer, cmd *cobra.Command, args
 		return err
 	}
 
-	mapper, resourceMapper, r, cmdNamespace, err := getMapperAndResult(f, args, options, editMode)
+	mapper, originalResult, updatedResultsGetter, cmdNamespace, err := getMapperAndResult(f, args, options, editMode)
 	if err != nil {
 		return err
 	}
@@ -147,17 +147,12 @@ func runEdit(f cmdutil.Factory, out, errOut io.Writer, cmd *cobra.Command, args
 		return err
 	}
 
-	normalEditInfos, err := r.Infos()
-	if err != nil {
-		return err
-	}
-
 	var (
 		windowsLineEndings = cmdutil.GetFlagBool(cmd, "windows-line-endings")
 		edit               = editor.NewDefaultEditor(f.EditorEnvs())
 	)
 
-	editFn := func(info *resource.Info, err error) error {
+	editFn := func(infos []*resource.Info) error {
 		var (
 			results  = editResults{}
 			original = []byte{}
@@ -166,16 +161,7 @@ func runEdit(f cmdutil.Factory, out, errOut io.Writer, cmd *cobra.Command, args
 		)
 
 		containsError := false
-		var infos []*resource.Info
 		for {
-			switch editMode {
-			case NormalEditMode:
-				infos = normalEditInfos
-			case EditBeforeCreateMode:
-				infos = []*resource.Info{info}
-			default:
-				err = fmt.Errorf("Not supported edit mode %q", editMode)
-			}
 			originalObj, err := resource.AsVersionedObject(infos, false, defaultVersion, encoder)
 			if err != nil {
 				return err
@@ -212,17 +198,10 @@ func runEdit(f cmdutil.Factory, out, errOut io.Writer, cmd *cobra.Command, args
 			if err != nil {
 				return preservedFile(err, results.file, errOut)
 			}
-			if editMode == NormalEditMode || containsError {
-				if bytes.Equal(stripComments(editedDiff), stripComments(edited)) {
-					// Ugly hack right here. We will hit this either (1) when we try to
-					// save the same changes we tried to save in the previous iteration
-					// which means our changes are invalid or (2) when we exit the second
-					// time. The second case is more usual so we can probably live with it.
-					// TODO: A less hacky fix would be welcome :)
-					return preservedFile(fmt.Errorf("%s", "Edit cancelled, no valid changes were saved."), file, errOut)
-				}
+			// If we're retrying the loop because of an error, and no change was made in the file, short-circuit
+			if containsError && bytes.Equal(stripComments(editedDiff), stripComments(edited)) {
+				return preservedFile(fmt.Errorf("%s", "Edit cancelled, no valid changes were saved."), file, errOut)
 			}
-
 			// cleanup any file from the previous pass
 			if len(results.file) > 0 {
 				os.Remove(results.file)
@@ -266,38 +245,37 @@ func runEdit(f cmdutil.Factory, out, errOut io.Writer, cmd *cobra.Command, args
 			}
 
 			// parse the edited file
-			updates, err := resourceMapper.InfoForData(edited, "edited-file")
-			if err != nil {
+			var updatedVisitor resource.Visitor
+			if updatedInfos, err := updatedResultsGetter(edited).Infos(); err != nil {
 				// syntax error
 				containsError = true
 				results.header.reasons = append(results.header.reasons, editReason{head: fmt.Sprintf("The edited file had a syntax error: %v", err)})
 				continue
+			} else {
+				updatedVisitor = resource.InfoListVisitor(updatedInfos)
 			}
 			// not a syntax error as it turns out...
 			containsError = false
 
-			namespaceVisitor := resource.NewFlattenListVisitor(updates, resourceMapper)
+			namespaceVisitor := updatedVisitor
 			// need to make sure the original namespace wasn't changed while editing
 			if err = namespaceVisitor.Visit(resource.RequireNamespace(cmdNamespace)); err != nil {
 				return preservedFile(err, file, errOut)
 			}
 
 			// iterate through all items to apply annotations
-			mutatedObjects, err := visitAnnotation(cmd, f, updates, resourceMapper, encoder)
-			if err != nil {
+			annotationVisitor := updatedVisitor
+			if _, err := visitAnnotation(cmd, f, annotationVisitor, encoder); err != nil {
 				return preservedFile(err, file, errOut)
 			}
 
-			// if we mutated a list in the visitor, persist the changes on the overall object
-			if meta.IsListType(updates.Object) {
-				meta.SetList(updates.Object, mutatedObjects)
-			}
-
 			switch editMode {
 			case NormalEditMode:
-				err = visitToPatch(originalObj, updates, mapper, resourceMapper, encoder, out, errOut, defaultVersion, &results, file)
+				patchVisitor := updatedVisitor
+				err = visitToPatch(originalObj, patchVisitor, mapper, encoder, out, errOut, defaultVersion, &results, file)
 			case EditBeforeCreateMode:
-				err = visitToCreate(updates, mapper, resourceMapper, out, errOut, defaultVersion, &results, file)
+				createVisitor := updatedVisitor
+				err = visitToCreate(createVisitor, mapper, out, errOut, defaultVersion, &results, file)
 			default:
 				err = fmt.Errorf("Not supported edit mode %q", editMode)
 			}
@@ -337,10 +315,16 @@ func runEdit(f cmdutil.Factory, out, errOut io.Writer, cmd *cobra.Command, args
 	switch editMode {
 	// If doing normal edit we cannot use Visit because we need to edit a list for convenience. Ref: #20519
 	case NormalEditMode:
-		return editFn(nil, nil)
+		infos, err := originalResult.Infos()
+		if err != nil {
+			return err
+		}
+		return editFn(infos)
 	// If doing an edit before created, we don't want a list and instead want the normal behavior as kubectl create.
 	case EditBeforeCreateMode:
-		return r.Visit(editFn)
+		return originalResult.Visit(func(info *resource.Info, err error) error {
+			return editFn([]*resource.Info{info})
+		})
 	default:
 		return fmt.Errorf("Not supported edit mode %q", editMode)
 	}
@@ -366,7 +350,9 @@ func getPrinter(cmd *cobra.Command) (*editPrinterOptions, error) {
 	}
 }
 
-func getMapperAndResult(f cmdutil.Factory, args []string, options *resource.FilenameOptions, editMode EditMode) (meta.RESTMapper, *resource.Mapper, *resource.Result, string, error) {
+type resultGetter func([]byte) *resource.Result
+
+func getMapperAndResult(f cmdutil.Factory, args []string, options *resource.FilenameOptions, editMode EditMode) (meta.RESTMapper, *resource.Result, resultGetter, string, error) {
 	cmdNamespace, enforceNamespace, err := f.DefaultNamespace()
 	if err != nil {
 		return nil, nil, nil, "", err
@@ -384,18 +370,8 @@ func getMapperAndResult(f cmdutil.Factory, args []string, options *resource.File
 	if err != nil {
 		return nil, nil, nil, "", err
 	}
-	resourceMapper := &resource.Mapper{
-		ObjectTyper:  typer,
-		RESTMapper:   mapper,
-		ClientMapper: resource.ClientMapperFunc(f.ClientForMapping),
 
-		// NB: we use `f.Decoder(false)` to get a plain deserializer for
-		// the resourceMapper, since it's used to read in edits and
-		// we don't want to convert into the internal version when
-		// reading in edits (this would cause us to potentially try to
-		// compare two different GroupVersions).
-		Decoder: f.Decoder(false),
-	}
+	// resource builder to read objects from the original file or arg invocation
 	var b *resource.Builder
 	switch editMode {
 	case NormalEditMode:
@@ -407,31 +383,42 @@ func getMapperAndResult(f cmdutil.Factory, args []string, options *resource.File
 	default:
 		return nil, nil, nil, "", fmt.Errorf("Not supported edit mode %q", editMode)
 	}
-	r := b.NamespaceParam(cmdNamespace).DefaultNamespace().
+
+	originalResult := b.NamespaceParam(cmdNamespace).DefaultNamespace().
 		FilenameParam(enforceNamespace, options).
 		ContinueOnError().
 		Flatten().
 		Do()
-	err = r.Err()
+	err = originalResult.Err()
 	if err != nil {
 		return nil, nil, nil, "", err
 	}
-	return mapper, resourceMapper, r, cmdNamespace, err
+
+	updatedResultGetter := func(data []byte) *resource.Result {
+		// resource builder to read objects from the original file or arg invocation
+		var b *resource.Builder
+		switch editMode {
+		case NormalEditMode:
+			b = resource.NewBuilder(mapper, typer, resource.ClientMapperFunc(f.ClientForMapping), f.Decoder(true))
+		case EditBeforeCreateMode:
+			b = resource.NewBuilder(mapper, typer, resource.ClientMapperFunc(f.UnstructuredClientForMapping), unstructured.UnstructuredJSONScheme)
+		}
+		return b.Stream(bytes.NewReader(data), "edited-file").ContinueOnError().Flatten().Do()
+	}
+
+	return mapper, originalResult, updatedResultGetter, cmdNamespace, err
 }
 
 func visitToPatch(
 	originalObj runtime.Object,
-	updates *resource.Info,
+	patchVisitor resource.Visitor,
 	mapper meta.RESTMapper,
-	resourceMapper *resource.Mapper,
 	encoder runtime.Encoder,
 	out, errOut io.Writer,
 	defaultVersion schema.GroupVersion,
 	results *editResults,
 	file string,
 ) error {
-
-	patchVisitor := resource.NewFlattenListVisitor(updates, resourceMapper)
 	err := patchVisitor.Visit(func(info *resource.Info, incomingErr error) error {
 		currOriginalObj := originalObj
 
@@ -515,8 +502,7 @@ func visitToPatch(
 	return err
 }
 
-func visitToCreate(updates *resource.Info, mapper meta.RESTMapper, resourceMapper *resource.Mapper, out, errOut io.Writer, defaultVersion schema.GroupVersion, results *editResults, file string) error {
-	createVisitor := resource.NewFlattenListVisitor(updates, resourceMapper)
+func visitToCreate(createVisitor resource.Visitor, mapper meta.RESTMapper, out, errOut io.Writer, defaultVersion schema.GroupVersion, results *editResults, file string) error {
 	err := createVisitor.Visit(func(info *resource.Info, incomingErr error) error {
 		results.version = defaultVersion
 		if err := createAndRefresh(info); err != nil {
@@ -528,9 +514,8 @@ func visitToCreate(updates *resource.Info, mapper meta.RESTMapper, resourceMappe
 	return err
 }
 
-func visitAnnotation(cmd *cobra.Command, f cmdutil.Factory, updates *resource.Info, resourceMapper *resource.Mapper, encoder runtime.Encoder) ([]runtime.Object, error) {
+func visitAnnotation(cmd *cobra.Command, f cmdutil.Factory, annotationVisitor resource.Visitor, encoder runtime.Encoder) ([]runtime.Object, error) {
 	mutatedObjects := []runtime.Object{}
-	annotationVisitor := resource.NewFlattenListVisitor(updates, resourceMapper)
 	// iterate through all items to apply annotations
 	err := annotationVisitor.Visit(func(info *resource.Info, incomingErr error) error {
 		// put configuration annotation in "updates"

pkg/kubectl/cmd/edit_test.go

@@ -221,6 +221,20 @@ func TestEdit(t *testing.T) {
 				Client:               fake.CreateHTTPClient(reqResp),
 			}, nil
 		}
+		tf.UnstructuredClientForMappingFunc = func(mapping *meta.RESTMapping) (resource.RESTClient, error) {
+			versionedAPIPath := ""
+			if mapping.GroupVersionKind.Group == "" {
+				versionedAPIPath = "/api/" + mapping.GroupVersionKind.Version
+			} else {
+				versionedAPIPath = "/apis/" + mapping.GroupVersionKind.Group + "/" + mapping.GroupVersionKind.Version
+			}
+			return &fake.RESTClient{
+				APIRegistry:          api.Registry,
+				VersionedAPIPath:     versionedAPIPath,
+				NegotiatedSerializer: unstructuredSerializer,
+				Client:               fake.CreateHTTPClient(reqResp),
+			}, nil
+		}
 
 		if len(testcase.Namespace) > 0 {
 			tf.Namespace = testcase.Namespace

pkg/kubectl/cmd/testdata/edit/testcase-create-list-error/1.request

@@ -1,31 +1,32 @@
 {
-	"kind": "Service",
 	"apiVersion": "v1",
+	"kind": "Service",
 	"metadata": {
-		"name": "svc1",
-		"namespace": "edit-test",
-		"selfLink": "/api/v1/namespaces/edit-test/services/svc1",
-		"uid": "4149f70e-e9dc-11e6-8c3b-acbc32c1ca87",
 		"creationTimestamp": "2017-02-03T06:44:47Z",
 		"labels": {
 			"app": "svc1modified"
-		}
+		},
+		"name": "svc1",
+		"namespace": "edit-test",
+		"resourceVersion": "",
+		"selfLink": "/api/v1/namespaces/edit-test/services/svc1",
+		"uid": "4149f70e-e9dc-11e6-8c3b-acbc32c1ca87"
 	},
 	"spec": {
+		"clusterIP": "10.0.0.118",
 		"ports": [
 			{
 				"name": "81",
-				"protocol": "TCP",
 				"port": 82,
+				"protocol": "TCP",
 				"targetPort": 81
 			}
 		],
 		"selector": {
 			"app": "svc1"
 		},
-		"clusterIP": "10.0.0.118",
-		"type": "ClusterIP",
-		"sessionAffinity": "None"
+		"sessionAffinity": "None",
+		"type": "ClusterIP"
 	},
 	"status": {
 		"loadBalancer": {}

pkg/kubectl/cmd/testdata/edit/testcase-create-list-error/3.request

@@ -1,31 +1,32 @@
 {
-	"kind": "Service",
 	"apiVersion": "v1",
+	"kind": "Service",
 	"metadata": {
-		"name": "svc2",
-		"namespace": "edit-test",
-		"selfLink": "/api/v1/namespaces/edit-test/services/svc2",
-		"uid": "3e9b10db-e9dc-11e6-8c3b-acbc32c1ca87",
 		"creationTimestamp": "2017-02-03T06:44:43Z",
 		"labels": {
 			"app": "svc2modified"
-		}
+		},
+		"name": "svc2",
+		"namespace": "edit-test",
+		"resourceVersion": "",
+		"selfLink": "/api/v1/namespaces/edit-test/services/svc2",
+		"uid": "3e9b10db-e9dc-11e6-8c3b-acbc32c1ca87"
 	},
 	"spec": {
+		"clusterIP": "10.0.0.182.1",
 		"ports": [
 			{
 				"name": "80",
-				"protocol": "VHF",
 				"port": 80,
+				"protocol": "VHF",
 				"targetPort": 80
 			}
 		],
 		"selector": {
 			"app": "svc2"
 		},
-		"clusterIP": "10.0.0.182.1",
-		"type": "ClusterIP",
-		"sessionAffinity": "None"
+		"sessionAffinity": "None",
+		"type": "ClusterIP"
 	},
 	"status": {
 		"loadBalancer": {}

pkg/kubectl/cmd/testdata/edit/testcase-create-list/1.request

@@ -1,31 +1,27 @@
 {
-	"kind": "Service",
 	"apiVersion": "v1",
+	"kind": "Service",
 	"metadata": {
-		"name": "svc1",
-		"namespace": "edit-test",
-		"creationTimestamp": null,
 		"labels": {
 			"app": "svc1",
 			"new-label": "new-value"
-		}
+		},
+		"name": "svc1",
+		"namespace": "edit-test"
 	},
 	"spec": {
 		"ports": [
 			{
 				"name": "81",
-				"protocol": "TCP",
 				"port": 82,
+				"protocol": "TCP",
 				"targetPort": 81
 			}
 		],
 		"selector": {
 			"app": "svc1"
 		},
-		"type": "ClusterIP",
-		"sessionAffinity": "None"
-	},
-	"status": {
-		"loadBalancer": {}
+		"sessionAffinity": "None",
+		"type": "ClusterIP"
 	}
 }

pkg/kubectl/cmd/testdata/edit/testcase-create-list/3.request

@@ -1,20 +1,19 @@
 {
-	"kind": "Service",
 	"apiVersion": "v1",
+	"kind": "Service",
 	"metadata": {
-		"name": "svc2",
-		"namespace": "edit-test",
-		"creationTimestamp": null,
 		"labels": {
 			"app": "svc2"
-		}
+		},
+		"name": "svc2",
+		"namespace": "edit-test"
 	},
 	"spec": {
 		"ports": [
 			{
 				"name": "80",
-				"protocol": "TCP",
 				"port": 80,
+				"protocol": "TCP",
 				"targetPort": 81
 			}
 		],
@@ -22,10 +21,7 @@
 			"app": "svc2",
 			"new-label": "new-value"
 		},
-		"type": "ClusterIP",
-		"sessionAffinity": "None"
-	},
-	"status": {
-		"loadBalancer": {}
+		"sessionAffinity": "None",
+		"type": "ClusterIP"
 	}
 }

pkg/kubectl/cmd/testdata/edit/testcase-syntax-error/2.edited

@@ -2,7 +2,7 @@
 # and an empty file will abort the edit. If an error occurs while saving this file will be
 # reopened with the relevant failures.
 #
-# The edited file had a syntax error: unable to decode "edited-file": yaml: line 17: could not find expected ':'
+# The edited file had a syntax error: error converting YAML to JSON: yaml: line 17: could not find expected ':'
 #
 apiVersion: v1
 kind: Service

pkg/kubectl/cmd/testdata/edit/testcase-syntax-error/2.original

@@ -2,7 +2,7 @@
 # and an empty file will abort the edit. If an error occurs while saving this file will be
 # reopened with the relevant failures.
 #
-# The edited file had a syntax error: unable to decode "edited-file": yaml: line 17: could not find expected ':'
+# The edited file had a syntax error: error converting YAML to JSON: yaml: line 17: could not find expected ':'
 #
 apiVersion: v1
 kind: Service

pkg/kubectl/resource/visitor.go

@@ -695,3 +695,13 @@ func FilterBySelector(s labels.Selector) FilterFunc {
 		return true, nil
 	}
 }
+
+type InfoListVisitor []*Info
+
+func (infos InfoListVisitor) Visit(fn VisitorFunc) error {
+	var err error
+	for _, i := range infos {
+		err = fn(i, err)
+	}
+	return err
+}