Add inline patching to kubectl update.

docs/kubectl.md

@@ -236,6 +236,9 @@ Examples:
 
   $ cat pod.json | kubectl update -f -
   <update a pod based on the json passed into stdin>
+  
+  $ kubectl update pods my-pod --patch='{ "labels": { "foo": "bar" } }'
+  <update a pod by downloading it, applying the patch, then updating>
 
 Usage:
 ```
@@ -261,6 +264,7 @@ Usage:
       --match-server-version=false: Require server version to match client version
   -n, --namespace="": If present, the namespace scope for this CLI request.
       --ns-path="/home/username/.kubernetes_ns": Path to the namespace info file that holds the namespace context to use for CLI requests.
+      --patch="": A JSON document to override the existing resource.  The resource is downloaded, then patched with the JSON, the re-updated
   -s, --server="": The address of the Kubernetes API server
       --stderrthreshold=2: logs at or above this threshold go to stderr
       --token="": Bearer token for authentication to the API server.

pkg/kubectl/cmd/update.go

@@ -37,27 +37,68 @@ Examples:
   <update a pod using the data in pod.json>
 
   $ cat pod.json | kubectl update -f -
-  <update a pod based on the json passed into stdin>`,
+  <update a pod based on the json passed into stdin>
+  
+  $ kubectl update pods my-pod --patch='{ "labels": { "foo": "bar" } }'
+  <update a pod by downloading it, applying the patch, then updating>`,
 		Run: func(cmd *cobra.Command, args []string) {
 			filename := GetFlagString(cmd, "filename")
-			if len(filename) == 0 {
-				usageError(cmd, "Must specify filename to update")
+			patch := GetFlagString(cmd, "patch")
+			if len(filename) == 0 && len(patch) == 0 {
+				usageError(cmd, "Must specify --filename or --patch to update")
+			}
+			if len(filename) != 0 && len(patch) != 0 {
+				usageError(cmd, "Can not specify both --filename and --patch")
+			}
+			var name string
+			if len(filename) > 0 {
+				name = updateWithFile(cmd, f, filename)
+			} else {
+				name = updateWithPatch(cmd, args, f, patch)
 			}
-			schema, err := f.Validator(cmd)
-			checkErr(err)
-			mapper, typer := f.Object(cmd)
-			mapping, namespace, name, data := ResourceFromFile(cmd, filename, typer, mapper, schema)
-			client, err := f.RESTClient(cmd, mapping)
-			checkErr(err)
-
-			err = CompareNamespaceFromFile(cmd, namespace)
-			checkErr(err)
-
-			err = resource.NewHelper(client, mapping).Update(namespace, name, true, data)
-			checkErr(err)
 			fmt.Fprintf(out, "%s\n", name)
 		},
 	}
 	cmd.Flags().StringP("filename", "f", "", "Filename or URL to file to use to update the resource")
+	cmd.Flags().String("patch", "", "A JSON document to override the existing resource.  The resource is downloaded, then patched with the JSON, the re-updated")
 	return cmd
 }
+
+func updateWithPatch(cmd *cobra.Command, args []string, f *Factory, patch string) string {
+	mapper, _ := f.Object(cmd)
+	mapping, namespace, name := ResourceFromArgs(cmd, args, mapper)
+	client, err := f.RESTClient(cmd, mapping)
+	checkErr(err)
+
+	helper := resource.NewHelper(client, mapping)
+	obj, err := helper.Get(namespace, name)
+	checkErr(err)
+
+	Merge(obj, patch, mapping.Kind)
+
+	data, err := helper.Codec.Encode(obj)
+	checkErr(err)
+
+	err = helper.Update(namespace, name, true, data)
+	checkErr(err)
+	return name
+}
+
+func updateWithFile(cmd *cobra.Command, f *Factory, filename string) string {
+	schema, err := f.Validator(cmd)
+	checkErr(err)
+	mapper, typer := f.Object(cmd)
+
+	mapping, namespace, name, data := ResourceFromFile(cmd, filename, typer, mapper, schema)
+
+	client, err := f.RESTClient(cmd, mapping)
+	checkErr(err)
+
+	err = CompareNamespaceFromFile(cmd, namespace)
+	checkErr(err)
+
+	err = resource.NewHelper(client, mapping).Update(namespace, name, true, data)
+	checkErr(err)
+
+	return name
+}