Merge pull request #23673 from metral/multiple-resources

Automatic merge from submit-queue

allow kubectl subcmds to process multiple resources

~~autoscale, expose & patch~~ Many kubectl subcommands were limited to processing one resource at a time.

This PR allows those subcommands to process multiple resources.

This PR is in reference to https://github.com/kubernetes/kubernetes/pull/23116#issuecomment-202360784 by @deads2k

hack/test-cmd.sh

@@ -876,6 +876,166 @@ __EOF__
   # Clean up
   kubectl delete deployment nginx "${kube_flags[@]}"
 
+
+  #####################################
+  # Recursive Resources via directory #
+  #####################################
+
+  ### Create multiple busybox PODs recursively from directory of YAML files
+  # Pre-condition: no POD exists
+  create_and_use_new_namespace
+  kube::test::get_object_assert pods "{{range.items}}{{$id_field}}:{{end}}" ''
+  # Command
+  output_message=$(! kubectl create -f hack/testdata/recursive/pod --recursive 2>&1 "${kube_flags[@]}")
+  # Post-condition: busybox0 & busybox1 PODs are created, and since busybox2 is malformed, it should error
+  kube::test::get_object_assert pods "{{range.items}}{{$id_field}}:{{end}}" 'busybox0:busybox1:'
+  kube::test::if_has_string "${output_message}" 'error validating data: kind not set'
+
+  ## Replace multiple busybox PODs recursively from directory of YAML files
+  # Pre-condition: busybox0 & busybox1 PODs exist
+  kube::test::get_object_assert pods "{{range.items}}{{$id_field}}:{{end}}" 'busybox0:busybox1:'
+  # Command
+  output_message=$(! kubectl replace -f hack/testdata/recursive/pod-modify --recursive 2>&1 "${kube_flags[@]}")
+  # Post-condition: busybox0 & busybox1 PODs are replaced, and since busybox2 is malformed, it should error
+  kube::test::get_object_assert pods "{{range.items}}{{${labels_field}.status}}:{{end}}" 'replaced:replaced:'
+  kube::test::if_has_string "${output_message}" 'error validating data: kind not set'
+
+  ## Describe multiple busybox PODs recursively from directory of YAML files
+  # Pre-condition: busybox0 & busybox1 PODs exist
+  kube::test::get_object_assert pods "{{range.items}}{{$id_field}}:{{end}}" 'busybox0:busybox1:'
+  # Command
+  output_message=$(! kubectl describe -f hack/testdata/recursive/pod --recursive 2>&1 "${kube_flags[@]}")
+  # Post-condition: busybox0 & busybox1 PODs are described, and since busybox2 is malformed, it should error
+  kube::test::if_has_string "${output_message}" "app=busybox0"
+  kube::test::if_has_string "${output_message}" "app=busybox1"
+  kube::test::if_has_string "${output_message}" "Object 'Kind' is missing"
+
+  ## Annotate multiple busybox PODs recursively from directory of YAML files
+  # Pre-condition: busybox0 & busybox1 PODs exist
+  kube::test::get_object_assert pods "{{range.items}}{{$id_field}}:{{end}}" 'busybox0:busybox1:'
+  # Command
+  output_message=$(! kubectl annotate -f hack/testdata/recursive/pod annotatekey='annotatevalue' --recursive 2>&1 "${kube_flags[@]}")
+  # Post-condition: busybox0 & busybox1 PODs are annotated, and since busybox2 is malformed, it should error
+  kube::test::get_object_assert pods "{{range.items}}{{${annotations_field}.annotatekey}}:{{end}}" 'annotatevalue:annotatevalue:'
+  kube::test::if_has_string "${output_message}" "Object 'Kind' is missing"
+
+  ## Apply multiple busybox PODs recursively from directory of YAML files
+  # Pre-condition: busybox0 & busybox1 PODs exist
+  kube::test::get_object_assert pods "{{range.items}}{{$id_field}}:{{end}}" 'busybox0:busybox1:'
+  # Command
+  output_message=$(! kubectl apply -f hack/testdata/recursive/pod-modify --recursive 2>&1 "${kube_flags[@]}")
+  # Post-condition: busybox0 & busybox1 PODs are updated, and since busybox2 is malformed, it should error
+  kube::test::get_object_assert pods "{{range.items}}{{${labels_field}.status}}:{{end}}" 'replaced:replaced:'
+  kube::test::if_has_string "${output_message}" 'error validating data: kind not set'
+
+  ## Convert multiple busybox PODs recursively from directory of YAML files
+  # Pre-condition: busybox0 & busybox1 PODs exist
+  kube::test::get_object_assert pods "{{range.items}}{{$id_field}}:{{end}}" 'busybox0:busybox1:'
+  # Command
+  output_message=$(! kubectl convert -f hack/testdata/recursive/pod --recursive 2>&1 "${kube_flags[@]}")
+  # Post-condition: busybox0 & busybox1 PODs are converted, and since busybox2 is malformed, it should error
+  kube::test::get_object_assert pods "{{range.items}}{{$id_field}}:{{end}}" 'busybox0:busybox1:'
+  kube::test::if_has_string "${output_message}" "Object 'Kind' is missing"
+
+  ## Get multiple busybox PODs recursively from directory of YAML files
+  # Pre-condition: busybox0 & busybox1 PODs exist
+  kube::test::get_object_assert pods "{{range.items}}{{$id_field}}:{{end}}" 'busybox0:busybox1:'
+  # Command
+  output_message1=$(kubectl get -f hack/testdata/recursive/pod --recursive 2>&1 "${kube_flags[@]}" -o go-template="{{range.items}}{{$id_field}}:{{end}}")
+  output_message2=$(! kubectl get -f hack/testdata/recursive/pod --recursive 2>&1 "${kube_flags[@]}")
+  # Post-condition: busybox0 & busybox1 PODs are retrieved, but because busybox2 is malformed, it should not show up
+  kube::test::if_has_string "${output_message1}" "busybox0:busybox1:"
+  kube::test::if_has_string "${output_message2}" "Object 'Kind' is missing"
+
+  ## Label multiple busybox PODs recursively from directory of YAML files
+  # Pre-condition: busybox0 & busybox1 PODs exist
+  kube::test::get_object_assert pods "{{range.items}}{{$id_field}}:{{end}}" 'busybox0:busybox1:'
+  # Command
+  output_message=$(! kubectl label -f hack/testdata/recursive/pod mylabel='myvalue' --recursive 2>&1 "${kube_flags[@]}")
+  echo $output_message
+  # Post-condition: busybox0 & busybox1 PODs are labeled, but because busybox2 is malformed, it should not show up
+  kube::test::get_object_assert pods "{{range.items}}{{${labels_field}.mylabel}}:{{end}}" 'myvalue:myvalue:'
+  kube::test::if_has_string "${output_message}" "Object 'Kind' is missing"
+
+  ## Patch multiple busybox PODs recursively from directory of YAML files
+  # Pre-condition: busybox0 & busybox1 PODs exist
+  kube::test::get_object_assert pods "{{range.items}}{{$id_field}}:{{end}}" 'busybox0:busybox1:'
+  # Command
+  output_message=$(! kubectl patch -f hack/testdata/recursive/pod -p='{"spec":{"containers":[{"name":"busybox","image":"prom/busybox"}]}}' --recursive 2>&1 "${kube_flags[@]}")
+  echo $output_message
+  # Post-condition: busybox0 & busybox1 PODs are patched, but because busybox2 is malformed, it should not show up
+  kube::test::get_object_assert pods "{{range.items}}{{$image_field}}:{{end}}" 'prom/busybox:prom/busybox:'
+  kube::test::if_has_string "${output_message}" "Object 'Kind' is missing"
+
+  ### Delete multiple busybox PODs recursively from directory of YAML files
+  # Pre-condition: busybox0 & busybox1 PODs exist
+  kube::test::get_object_assert pods "{{range.items}}{{$id_field}}:{{end}}" 'busybox0:busybox1:'
+  # Command
+  output_message=$(! kubectl delete -f hack/testdata/recursive/pod --recursive --grace-period=0 2>&1 "${kube_flags[@]}")
+  # Post-condition: busybox0 & busybox1 PODs are deleted, and since busybox2 is malformed, it should error
+  kube::test::get_object_assert pods "{{range.items}}{{$id_field}}:{{end}}" ''
+  kube::test::if_has_string "${output_message}" "Object 'Kind' is missing"
+
+  ### Create replication controller recursively from directory of YAML files
+  # Pre-condition: no replication controller exists
+  kube::test::get_object_assert rc "{{range.items}}{{$id_field}}:{{end}}" ''
+  # Command
+  ! kubectl create -f hack/testdata/recursive/rc --recursive "${kube_flags[@]}"
+  # Post-condition: frontend replication controller is created
+  kube::test::get_object_assert rc "{{range.items}}{{$id_field}}:{{end}}" 'busybox0:busybox1:'
+
+  ### Autoscale multiple replication controllers recursively from directory of YAML files
+  # Pre-condition: busybox0 & busybox1 replication controllers exist & 1
+  # replica each
+  kube::test::get_object_assert rc "{{range.items}}{{$id_field}}:{{end}}" 'busybox0:busybox1:'
+  kube::test::get_object_assert 'rc busybox0' "{{$rc_replicas_field}}" '1'
+  kube::test::get_object_assert 'rc busybox1' "{{$rc_replicas_field}}" '1'
+  # Command
+  output_message=$(! kubectl autoscale --min=1 --max=2 -f hack/testdata/recursive/rc --recursive 2>&1 "${kube_flags[@]}")
+  # Post-condition: busybox0 & busybox replication controllers are autoscaled
+  # with min. of 1 replica & max of 2 replicas, and since busybox2 is malformed, it should error
+  kube::test::get_object_assert 'hpa busybox0' "{{$hpa_min_field}} {{$hpa_max_field}} {{$hpa_cpu_field}}" '1 2 80'
+  kube::test::get_object_assert 'hpa busybox1' "{{$hpa_min_field}} {{$hpa_max_field}} {{$hpa_cpu_field}}" '1 2 80'
+  kube::test::if_has_string "${output_message}" "Object 'Kind' is missing"
+  kubectl delete hpa busybox0 "${kube_flags[@]}"
+  kubectl delete hpa busybox1 "${kube_flags[@]}"
+
+  ### Expose multiple replication controllers as service recursively from directory of YAML files
+  # Pre-condition: busybox0 & busybox1 replication controllers exist & 1
+  # replica each
+  kube::test::get_object_assert rc "{{range.items}}{{$id_field}}:{{end}}" 'busybox0:busybox1:'
+  kube::test::get_object_assert 'rc busybox0' "{{$rc_replicas_field}}" '1'
+  kube::test::get_object_assert 'rc busybox1' "{{$rc_replicas_field}}" '1'
+  # Command
+  output_message=$(! kubectl expose -f hack/testdata/recursive/rc --recursive --port=80 2>&1 "${kube_flags[@]}")
+  # Post-condition: service exists and the port is unnamed
+  kube::test::get_object_assert 'service busybox0' "{{$port_name}} {{$port_field}}" '<no value> 80'
+  kube::test::get_object_assert 'service busybox1' "{{$port_name}} {{$port_field}}" '<no value> 80'
+  kube::test::if_has_string "${output_message}" "Object 'Kind' is missing"
+
+  ### Scale multiple replication controllers recursively from directory of YAML files
+  # Pre-condition: busybox0 & busybox1 replication controllers exist & 1
+  # replica each
+  kube::test::get_object_assert rc "{{range.items}}{{$id_field}}:{{end}}" 'busybox0:busybox1:'
+  kube::test::get_object_assert 'rc busybox0' "{{$rc_replicas_field}}" '1'
+  kube::test::get_object_assert 'rc busybox1' "{{$rc_replicas_field}}" '1'
+  # Command
+  output_message=$(! kubectl scale --current-replicas=1 --replicas=2 -f hack/testdata/recursive/rc --recursive 2>&1 "${kube_flags[@]}")
+  # Post-condition: busybox0 & busybox replication controllers are scaled to 2 # replicas, and since busybox2 is malformed, it should error
+  kube::test::get_object_assert 'rc busybox0' "{{$rc_replicas_field}}" '2'
+  kube::test::get_object_assert 'rc busybox1' "{{$rc_replicas_field}}" '2'
+  kube::test::if_has_string "${output_message}" "Object 'Kind' is missing"
+
+  ### Delete multiple busybox replication controllers recursively from directory of YAML files
+  # Pre-condition: busybox0 & busybox1 PODs exist
+  kube::test::get_object_assert rc "{{range.items}}{{$id_field}}:{{end}}" 'busybox0:busybox1:'
+  # Command
+  output_message=$(! kubectl delete -f hack/testdata/recursive/rc --recursive --grace-period=0 2>&1 "${kube_flags[@]}")
+  # Post-condition: busybox0 & busybox1 replication controllers are deleted, and since busybox2 is malformed, it should error
+  kube::test::get_object_assert pods "{{range.items}}{{$id_field}}:{{end}}" ''
+  kube::test::if_has_string "${output_message}" "Object 'Kind' is missing"
+
+
   ##############
   # Namespaces #
   ##############

hack/testdata/recursive/deployment/deployment/nginx-broken.yaml

@@ -0,0 +1,18 @@
+apiVersion: extensions/v1beta1
+ind: Deployment
+metadata:
+  name: nginx2-deployment
+  labels:
+    app: nginx2-deployment
+spec:
+  replicas: 2
+  template:
+    metadata:
+      labels:
+        app: nginx2
+    spec:
+      containers:
+      - name: nginx
+        image: gcr.io/google-containers/nginx:1.7.9
+        ports:
+        - containerPort: 80

hack/testdata/recursive/deployment/deployment/nginx.yaml

@@ -0,0 +1,18 @@
+apiVersion: extensions/v1beta1
+kind: Deployment
+metadata:
+  name: nginx1-deployment
+  labels:
+    app: nginx1-deployment
+spec:
+  replicas: 2
+  template:
+    metadata:
+      labels:
+        app: nginx1
+    spec:
+      containers:
+      - name: nginx
+        image: gcr.io/google-containers/nginx:1.7.9
+        ports:
+        - containerPort: 80

hack/testdata/recursive/deployment/nginx.yaml

@@ -0,0 +1,18 @@
+apiVersion: extensions/v1beta1
+kind: Deployment
+metadata:
+  name: nginx0-deployment
+  labels:
+    app: nginx0-deployment
+spec:
+  replicas: 2
+  template:
+    metadata:
+      labels:
+        app: nginx0
+    spec:
+      containers:
+      - name: nginx
+        image: gcr.io/google-containers/nginx:1.7.9
+        ports:
+        - containerPort: 80

hack/testdata/recursive/pod-modify/busybox.yaml

@@ -0,0 +1,16 @@
+apiVersion: v1
+kind: Pod
+metadata:
+  name: busybox0
+  labels:
+    app: busybox0
+    status: replaced
+spec:
+  containers:
+  - image: busybox
+    command:
+      - sleep
+      - "3600"
+    imagePullPolicy: IfNotPresent
+    name: busybox
+  restartPolicy: Always

hack/testdata/recursive/pod-modify/pod/busybox-broken.yaml

@@ -0,0 +1,16 @@
+apiVersion: v1
+ind: Pod
+metadata:
+  name: busybox2
+  labels:
+    app: busybox2
+    status: replaced
+spec:
+  containers:
+  - image: busybox
+    command:
+      - sleep
+      - "3600"
+    imagePullPolicy: IfNotPresent
+    name: busybox
+  restartPolicy: Always

hack/testdata/recursive/pod-modify/pod/busybox.yaml

@@ -0,0 +1,16 @@
+apiVersion: v1
+kind: Pod
+metadata:
+  name: busybox1
+  labels:
+    app: busybox1
+    status: replaced
+spec:
+  containers:
+  - image: busybox
+    command:
+      - sleep
+      - "3600"
+    imagePullPolicy: IfNotPresent
+    name: busybox
+  restartPolicy: Always

hack/testdata/recursive/pod/busybox.yaml

@@ -0,0 +1,15 @@
+apiVersion: v1
+kind: Pod
+metadata:
+  name: busybox0
+  labels:
+    app: busybox0
+spec:
+  containers:
+  - image: busybox
+    command:
+      - sleep
+      - "3600"
+    imagePullPolicy: IfNotPresent
+    name: busybox
+  restartPolicy: Always

hack/testdata/recursive/pod/pod/busybox-broken.yaml

@@ -0,0 +1,15 @@
+apiVersion: v1
+ind: Pod
+metadata:
+  name: busybox2
+  labels:
+    app: busybox2
+spec:
+  containers:
+  - image: busybox
+    command:
+      - sleep
+      - "3600"
+    imagePullPolicy: IfNotPresent
+    name: busybox
+  restartPolicy: Always

hack/testdata/recursive/pod/pod/busybox.yaml

@@ -0,0 +1,15 @@
+apiVersion: v1
+kind: Pod
+metadata:
+  name: busybox1
+  labels:
+    app: busybox1
+spec:
+  containers:
+  - image: busybox
+    command:
+      - sleep
+      - "3600"
+    imagePullPolicy: IfNotPresent
+    name: busybox
+  restartPolicy: Always

hack/testdata/recursive/rc/busybox.yaml

@@ -0,0 +1,24 @@
+apiVersion: v1
+kind: ReplicationController
+metadata:
+  name: busybox0
+  labels:
+    app: busybox0
+spec:
+  replicas: 1
+  selector:
+    app: busybox0
+  template:
+    metadata:
+      name: busybox0
+      labels:
+        app: busybox0
+    spec:
+      containers:
+      - image: busybox
+        command:
+          - sleep
+          - "3600"
+        imagePullPolicy: IfNotPresent
+        name: busybox
+      restartPolicy: Always

hack/testdata/recursive/rc/rc/busybox-broken.yaml

@@ -0,0 +1,24 @@
+apiVersion: v1
+ind: ReplicationController
+metadata:
+  name: busybox2
+  labels:
+    app: busybox2
+spec:
+  replicas: 1
+  selector:
+    app: busybox2
+  template:
+    metadata:
+      name: busybox2
+      labels:
+        app: busybox2
+    spec:
+      containers:
+      - image: busybox
+        command:
+          - sleep
+          - "3600"
+        imagePullPolicy: IfNotPresent
+        name: busybox
+      restartPolicy: Always

hack/testdata/recursive/rc/rc/busybox.yaml

@@ -0,0 +1,24 @@
+apiVersion: v1
+kind: ReplicationController
+metadata:
+  name: busybox1
+  labels:
+    app: busybox1
+spec:
+  replicas: 1
+  selector:
+    app: busybox1
+  template:
+    metadata:
+      name: busybox1
+      labels:
+        app: busybox1
+    spec:
+      containers:
+      - image: busybox
+        command:
+          - sleep
+          - "3600"
+        imagePullPolicy: IfNotPresent
+        name: busybox
+      restartPolicy: Always

pkg/kubectl/cmd/autoscale.go

@@ -23,7 +23,7 @@ import (
 	"k8s.io/kubernetes/pkg/kubectl"
 	cmdutil "k8s.io/kubernetes/pkg/kubectl/cmd/util"
 	"k8s.io/kubernetes/pkg/kubectl/resource"
-	"k8s.io/kubernetes/pkg/util/errors"
+	utilerrors "k8s.io/kubernetes/pkg/util/errors"
 
 	"github.com/spf13/cobra"
 )
@@ -97,18 +97,10 @@ func RunAutoscale(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, args []
 		ResourceTypeOrNameArgs(false, args...).
 		Flatten().
 		Do()
-	infos, err := r.Infos()
+	err = r.Err()
 	if err != nil {
 		return err
 	}
-	if len(infos) > 1 {
-		return fmt.Errorf("multiple resources provided: %v", args)
-	}
-	info := infos[0]
-	mapping := info.ResourceMapping()
-	if err := f.CanBeAutoscaled(mapping.GroupVersionKind.GroupKind()); err != nil {
-		return err
-	}
 
 	// Get the generator, setup and validate all required parameters
 	generatorName := cmdutil.GetFlagString(cmd, "generator")
@@ -118,62 +110,84 @@ func RunAutoscale(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, args []
 		return cmdutil.UsageError(cmd, fmt.Sprintf("generator %q not found.", generatorName))
 	}
 	names := generator.ParamNames()
-	params := kubectl.MakeParams(cmd, names)
-	name := info.Name
-	params["default-name"] = name
 
-	params["scaleRef-kind"] = mapping.GroupVersionKind.Kind
-	params["scaleRef-name"] = name
-	params["scaleRef-apiVersion"] = mapping.GroupVersionKind.GroupVersion().String()
-
-	if err = kubectl.ValidateParams(names, params); err != nil {
-		return err
-	}
-	// Check for invalid flags used against the present generator.
-	if err := kubectl.EnsureFlagsValid(cmd, generators, generatorName); err != nil {
-		return err
-	}
-
-	// Generate new object
-	object, err := generator.Generate(params)
-	if err != nil {
-		return err
-	}
-
-	resourceMapper := &resource.Mapper{
-		ObjectTyper:  typer,
-		RESTMapper:   mapper,
-		ClientMapper: resource.ClientMapperFunc(f.ClientForMapping),
-		Decoder:      f.Decoder(true),
-	}
-	hpa, err := resourceMapper.InfoForObject(object, nil)
-	if err != nil {
-		return err
-	}
-	if cmdutil.ShouldRecord(cmd, hpa) {
-		if err := cmdutil.RecordChangeCause(hpa.Object, f.Command()); err != nil {
+	count := 0
+	err = r.Visit(func(info *resource.Info, err error) error {
+		if err != nil {
 			return err
 		}
-		object = hpa.Object
-	}
-	// TODO: extract this flag to a central location, when such a location exists.
-	if cmdutil.GetFlagBool(cmd, "dry-run") {
-		return f.PrintObject(cmd, mapper, object, out)
-	}
 
-	if err := kubectl.CreateOrUpdateAnnotation(cmdutil.GetFlagBool(cmd, cmdutil.ApplyAnnotationsFlag), hpa, f.JSONEncoder()); err != nil {
-		return err
-	}
+		mapping := info.ResourceMapping()
+		if err := f.CanBeAutoscaled(mapping.GroupVersionKind.GroupKind()); err != nil {
+			return err
+		}
 
-	object, err = resource.NewHelper(hpa.Client, hpa.Mapping).Create(namespace, false, object)
+		name := info.Name
+		params := kubectl.MakeParams(cmd, names)
+		params["default-name"] = name
+
+		params["scaleRef-kind"] = mapping.GroupVersionKind.Kind
+		params["scaleRef-name"] = name
+		params["scaleRef-apiVersion"] = mapping.GroupVersionKind.GroupVersion().String()
+
+		if err = kubectl.ValidateParams(names, params); err != nil {
+			return err
+		}
+		// Check for invalid flags used against the present generator.
+		if err := kubectl.EnsureFlagsValid(cmd, generators, generatorName); err != nil {
+			return err
+		}
+
+		// Generate new object
+		object, err := generator.Generate(params)
+		if err != nil {
+			return err
+		}
+
+		resourceMapper := &resource.Mapper{
+			ObjectTyper:  typer,
+			RESTMapper:   mapper,
+			ClientMapper: resource.ClientMapperFunc(f.ClientForMapping),
+			Decoder:      f.Decoder(true),
+		}
+		hpa, err := resourceMapper.InfoForObject(object, nil)
+		if err != nil {
+			return err
+		}
+		if cmdutil.ShouldRecord(cmd, hpa) {
+			if err := cmdutil.RecordChangeCause(hpa.Object, f.Command()); err != nil {
+				return err
+			}
+			object = hpa.Object
+		}
+		// TODO: extract this flag to a central location, when such a location exists.
+		if cmdutil.GetFlagBool(cmd, "dry-run") {
+			return f.PrintObject(cmd, mapper, object, out)
+		}
+
+		if err := kubectl.CreateOrUpdateAnnotation(cmdutil.GetFlagBool(cmd, cmdutil.ApplyAnnotationsFlag), hpa, f.JSONEncoder()); err != nil {
+			return err
+		}
+
+		object, err = resource.NewHelper(hpa.Client, hpa.Mapping).Create(namespace, false, object)
+		if err != nil {
+			return err
+		}
+
+		count++
+		if len(cmdutil.GetFlagString(cmd, "output")) > 0 {
+			return f.PrintObject(cmd, mapper, object, out)
+		}
+
+		cmdutil.PrintSuccess(mapper, false, out, info.Mapping.Resource, info.Name, "autoscaled")
+		return nil
+	})
 	if err != nil {
 		return err
 	}
-
-	if len(cmdutil.GetFlagString(cmd, "output")) > 0 {
-		return f.PrintObject(cmd, mapper, object, out)
+	if count == 0 {
+		return fmt.Errorf("no objects passed to autoscale")
 	}
-	cmdutil.PrintSuccess(mapper, false, out, info.Mapping.Resource, info.Name, "autoscaled")
 	return nil
 }
 
@@ -186,5 +200,5 @@ func validateFlags(cmd *cobra.Command) error {
 	if cpu > 100 {
 		errs = append(errs, fmt.Errorf("CPU utilization (%%) cannot exceed 100"))
 	}
-	return errors.NewAggregate(errs)
+	return utilerrors.NewAggregate(errs)
 }

pkg/kubectl/cmd/convert.go

@@ -154,15 +154,32 @@ func (o *ConvertOptions) Complete(f *cmdutil.Factory, out io.Writer, cmd *cobra.
 
 // RunConvert implements the generic Convert command
 func (o *ConvertOptions) RunConvert() error {
-	infos, err := o.builder.Do().Infos()
+	r := o.builder.Do()
+	err := r.Err()
 	if err != nil {
 		return err
 	}
 
-	objects, err := resource.AsVersionedObject(infos, false, o.outputVersion.String(), o.encoder)
+	count := 0
+	err = r.Visit(func(info *resource.Info, err error) error {
+		if err != nil {
+			return err
+		}
+
+		infos := []*resource.Info{info}
+		objects, err := resource.AsVersionedObject(infos, false, o.outputVersion.String(), o.encoder)
+		if err != nil {
+			return err
+		}
+
+		count++
+		return o.printer.PrintObj(objects, o.out)
+	})
 	if err != nil {
 		return err
 	}
-
-	return o.printer.PrintObj(objects, o.out)
+	if count == 0 {
+		return fmt.Errorf("no objects passed to convert")
+	}
+	return nil
 }

pkg/kubectl/cmd/expose.go

@@ -140,20 +140,7 @@ func RunExpose(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, args []str
 		ResourceTypeOrNameArgs(false, args...).
 		Flatten().
 		Do()
-	infos, err := r.Infos()
-	if err != nil {
-		return err
-	}
-	if len(infos) > 1 {
-		return fmt.Errorf("multiple resources provided: %v", args)
-	}
-	info := infos[0]
-	mapping := info.ResourceMapping()
-	if err := f.CanBeExposed(mapping.GroupVersionKind.GroupKind()); err != nil {
-		return err
-	}
-	// Get the input object
-	inputObject, err := r.Object()
+	err = r.Err()
 	if err != nil {
 		return err
 	}
@@ -166,101 +153,118 @@ func RunExpose(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, args []str
 		return cmdutil.UsageError(cmd, fmt.Sprintf("generator %q not found.", generatorName))
 	}
 	names := generator.ParamNames()
-	params := kubectl.MakeParams(cmd, names)
-	name := info.Name
-	if len(name) > validation.DNS952LabelMaxLength {
-		name = name[:validation.DNS952LabelMaxLength]
-	}
-	params["default-name"] = name
 
-	// For objects that need a pod selector, derive it from the exposed object in case a user
-	// didn't explicitly specify one via --selector
-	if s, found := params["selector"]; found && kubectl.IsZero(s) {
-		s, err := f.MapBasedSelectorForObject(inputObject)
-		if err != nil {
-			return cmdutil.UsageError(cmd, fmt.Sprintf("couldn't retrieve selectors via --selector flag or introspection: %s", err))
-		}
-		params["selector"] = s
-	}
-
-	// For objects that need a port, derive it from the exposed object in case a user
-	// didn't explicitly specify one via --port
-	if port, found := params["port"]; found && kubectl.IsZero(port) {
-		ports, err := f.PortsForObject(inputObject)
-		if err != nil {
-			return cmdutil.UsageError(cmd, fmt.Sprintf("couldn't find port via --port flag or introspection: %s", err))
-		}
-		switch len(ports) {
-		case 0:
-			return cmdutil.UsageError(cmd, "couldn't find port via --port flag or introspection")
-		case 1:
-			params["port"] = ports[0]
-		default:
-			params["ports"] = strings.Join(ports, ",")
-		}
-	}
-	if kubectl.IsZero(params["labels"]) {
-		labels, err := f.LabelsForObject(inputObject)
+	err = r.Visit(func(info *resource.Info, err error) error {
 		if err != nil {
 			return err
 		}
-		params["labels"] = kubectl.MakeLabels(labels)
-	}
-	if err = kubectl.ValidateParams(names, params); err != nil {
-		return err
-	}
-	// Check for invalid flags used against the present generator.
-	if err := kubectl.EnsureFlagsValid(cmd, generators, generatorName); err != nil {
-		return err
-	}
 
-	// Generate new object
-	object, err := generator.Generate(params)
-	if err != nil {
-		return err
-	}
+		mapping := info.ResourceMapping()
+		if err := f.CanBeExposed(mapping.GroupVersionKind.GroupKind()); err != nil {
+			return err
+		}
 
-	if inline := cmdutil.GetFlagString(cmd, "overrides"); len(inline) > 0 {
-		codec := runtime.NewCodec(f.JSONEncoder(), f.Decoder(true))
-		object, err = cmdutil.Merge(codec, object, inline, mapping.GroupVersionKind.Kind)
+		params := kubectl.MakeParams(cmd, names)
+		name := info.Name
+		if len(name) > validation.DNS952LabelMaxLength {
+			name = name[:validation.DNS952LabelMaxLength]
+		}
+		params["default-name"] = name
+
+		// For objects that need a pod selector, derive it from the exposed object in case a user
+		// didn't explicitly specify one via --selector
+		if s, found := params["selector"]; found && kubectl.IsZero(s) {
+			s, err := f.MapBasedSelectorForObject(info.Object)
+			if err != nil {
+				return cmdutil.UsageError(cmd, fmt.Sprintf("couldn't retrieve selectors via --selector flag or introspection: %s", err))
+			}
+			params["selector"] = s
+		}
+
+		// For objects that need a port, derive it from the exposed object in case a user
+		// didn't explicitly specify one via --port
+		if port, found := params["port"]; found && kubectl.IsZero(port) {
+			ports, err := f.PortsForObject(info.Object)
+			if err != nil {
+				return cmdutil.UsageError(cmd, fmt.Sprintf("couldn't find port via --port flag or introspection: %s", err))
+			}
+			switch len(ports) {
+			case 0:
+				return cmdutil.UsageError(cmd, "couldn't find port via --port flag or introspection")
+			case 1:
+				params["port"] = ports[0]
+			default:
+				params["ports"] = strings.Join(ports, ",")
+			}
+		}
+		if kubectl.IsZero(params["labels"]) {
+			labels, err := f.LabelsForObject(info.Object)
+			if err != nil {
+				return err
+			}
+			params["labels"] = kubectl.MakeLabels(labels)
+		}
+		if err = kubectl.ValidateParams(names, params); err != nil {
+			return err
+		}
+		// Check for invalid flags used against the present generator.
+		if err := kubectl.EnsureFlagsValid(cmd, generators, generatorName); err != nil {
+			return err
+		}
+
+		// Generate new object
+		object, err := generator.Generate(params)
 		if err != nil {
 			return err
 		}
-	}
 
-	resourceMapper := &resource.Mapper{
-		ObjectTyper:  typer,
-		RESTMapper:   mapper,
-		ClientMapper: resource.ClientMapperFunc(f.ClientForMapping),
-		Decoder:      f.Decoder(true),
-	}
-	info, err = resourceMapper.InfoForObject(object, nil)
-	if err != nil {
-		return err
-	}
-	if cmdutil.ShouldRecord(cmd, info) {
-		if err := cmdutil.RecordChangeCause(object, f.Command()); err != nil {
+		if inline := cmdutil.GetFlagString(cmd, "overrides"); len(inline) > 0 {
+			codec := runtime.NewCodec(f.JSONEncoder(), f.Decoder(true))
+			object, err = cmdutil.Merge(codec, object, inline, mapping.GroupVersionKind.Kind)
+			if err != nil {
+				return err
+			}
+		}
+
+		resourceMapper := &resource.Mapper{
+			ObjectTyper:  typer,
+			RESTMapper:   mapper,
+			ClientMapper: resource.ClientMapperFunc(f.ClientForMapping),
+			Decoder:      f.Decoder(true),
+		}
+		info, err = resourceMapper.InfoForObject(object, nil)
+		if err != nil {
+			return err
+		}
+		if cmdutil.ShouldRecord(cmd, info) {
+			if err := cmdutil.RecordChangeCause(object, f.Command()); err != nil {
+				return err
+			}
+		}
+		info.Refresh(object, true)
+		// TODO: extract this flag to a central location, when such a location exists.
+		if cmdutil.GetFlagBool(cmd, "dry-run") {
+			return f.PrintObject(cmd, mapper, object, out)
+		}
+		if err := kubectl.CreateOrUpdateAnnotation(cmdutil.GetFlagBool(cmd, cmdutil.ApplyAnnotationsFlag), info, f.JSONEncoder()); err != nil {
 			return err
 		}
-	}
-	info.Refresh(object, true)
-	// TODO: extract this flag to a central location, when such a location exists.
-	if cmdutil.GetFlagBool(cmd, "dry-run") {
-		return f.PrintObject(cmd, mapper, object, out)
-	}
-	if err := kubectl.CreateOrUpdateAnnotation(cmdutil.GetFlagBool(cmd, cmdutil.ApplyAnnotationsFlag), info, f.JSONEncoder()); err != nil {
-		return err
-	}
 
-	// Serialize the object with the annotation applied.
-	object, err = resource.NewHelper(info.Client, info.Mapping).Create(namespace, false, object)
+		// Serialize the object with the annotation applied.
+		object, err = resource.NewHelper(info.Client, info.Mapping).Create(namespace, false, object)
+		if err != nil {
+			return err
+		}
+
+		if len(cmdutil.GetFlagString(cmd, "output")) > 0 {
+			return f.PrintObject(cmd, mapper, object, out)
+		}
+
+		cmdutil.PrintSuccess(mapper, false, out, info.Mapping.Resource, info.Name, "exposed")
+		return nil
+	})
 	if err != nil {
 		return err
 	}
-
-	if len(cmdutil.GetFlagString(cmd, "output")) > 0 {
-		return f.PrintObject(cmd, mapper, object, out)
-	}
-	cmdutil.PrintSuccess(mapper, false, out, info.Mapping.Resource, info.Name, "exposed")
 	return nil
 }

pkg/kubectl/cmd/get.go

@@ -26,6 +26,7 @@ import (
 	cmdutil "k8s.io/kubernetes/pkg/kubectl/cmd/util"
 	"k8s.io/kubernetes/pkg/kubectl/resource"
 	"k8s.io/kubernetes/pkg/runtime"
+	utilerrors "k8s.io/kubernetes/pkg/util/errors"
 	"k8s.io/kubernetes/pkg/watch"
 )
 
@@ -197,19 +198,39 @@ func RunGet(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, args []string
 		return nil
 	}
 
-	b := resource.NewBuilder(mapper, typer, resource.ClientMapperFunc(f.ClientForMapping), f.Decoder(true)).
+	r := resource.NewBuilder(mapper, typer, resource.ClientMapperFunc(f.ClientForMapping), f.Decoder(true)).
 		NamespaceParam(cmdNamespace).DefaultNamespace().AllNamespaces(allNamespaces).
 		FilenameParam(enforceNamespace, options.Recursive, options.Filenames...).
 		SelectorParam(selector).
 		ExportParam(export).
 		ResourceTypeOrNameArgs(true, args...).
 		ContinueOnError().
-		Latest()
+		Latest().
+		Flatten().
+		Do()
+	err = r.Err()
+	if err != nil {
+		return err
+	}
+
 	printer, generic, err := cmdutil.PrinterForCommand(cmd)
 	if err != nil {
 		return err
 	}
 
+	infos := []*resource.Info{}
+	allErrs := []error{}
+	err = r.Visit(func(info *resource.Info, err error) error {
+		if err != nil {
+			return err
+		}
+		infos = append(infos, info)
+		return nil
+	})
+	if err != nil {
+		allErrs = append(allErrs, err)
+	}
+
 	if generic {
 		clientConfig, err := f.ClientConfig()
 		if err != nil {
@@ -217,11 +238,7 @@ func RunGet(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, args []string
 		}
 
 		singular := false
-		r := b.Flatten().Do()
-		infos, err := r.IntoSingular(&singular).Infos()
-		if err != nil {
-			return err
-		}
+		r.IntoSingular(&singular)
 
 		// the outermost object will be converted to the output-version, but inner
 		// objects can use their mappings
@@ -237,10 +254,6 @@ func RunGet(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, args []string
 		return printer.PrintObj(obj, out)
 	}
 
-	infos, err := b.Flatten().Do().Infos()
-	if err != nil {
-		return err
-	}
 	objs := make([]runtime.Object, len(infos))
 	for ix := range infos {
 		objs[ix] = infos[ix].Object
@@ -262,7 +275,8 @@ func RunGet(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, args []string
 		for ix := range infos {
 			objs[ix], err = infos[ix].Mapping.ConvertToVersion(infos[ix].Object, version.String())
 			if err != nil {
-				return err
+				allErrs = append(allErrs, err)
+				continue
 			}
 		}
 
@@ -291,19 +305,21 @@ func RunGet(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, args []string
 		if printer == nil || lastMapping == nil || mapping == nil || mapping.Resource != lastMapping.Resource {
 			printer, err = f.PrinterForMapping(cmd, mapping, allNamespaces)
 			if err != nil {
-				return err
+				allErrs = append(allErrs, err)
+				continue
 			}
 			lastMapping = mapping
 		}
 		if _, found := printer.(*kubectl.HumanReadablePrinter); found {
 			if err := printer.PrintObj(original, w); err != nil {
-				return err
+				allErrs = append(allErrs, err)
 			}
 			continue
 		}
 		if err := printer.PrintObj(original, w); err != nil {
-			return err
+			allErrs = append(allErrs, err)
+			continue
 		}
 	}
-	return nil
+	return utilerrors.NewAggregate(allErrs)
 }

pkg/kubectl/cmd/patch.go

@@ -137,35 +137,41 @@ func RunPatch(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, args []stri
 		return err
 	}
 
-	infos, err := r.Infos()
-	if err != nil {
-		return err
-	}
-	if len(infos) > 1 {
-		return fmt.Errorf("multiple resources provided")
-	}
-	info := infos[0]
-	name, namespace := info.Name, info.Namespace
-	mapping := info.ResourceMapping()
-	client, err := f.ClientForMapping(mapping)
-	if err != nil {
-		return err
-	}
-
-	helper := resource.NewHelper(client, mapping)
-	patchedObject, err := helper.Patch(namespace, name, patchType, patchBytes)
-	if err != nil {
-		return err
-	}
-	if cmdutil.ShouldRecord(cmd, info) {
-		if err := cmdutil.RecordChangeCause(patchedObject, f.Command()); err == nil {
-			// don't return an error on failure.  The patch itself succeeded, its only the hint for that change that failed
-			// don't bother checking for failures of this replace, because a failure to indicate the hint doesn't fail the command
-			// also, don't force the replacement.  If the replacement fails on a resourceVersion conflict, then it means this
-			// record hint is likely to be invalid anyway, so avoid the bad hint
-			resource.NewHelper(client, mapping).Replace(namespace, name, false, patchedObject)
+	count := 0
+	err = r.Visit(func(info *resource.Info, err error) error {
+		if err != nil {
+			return err
 		}
+		name, namespace := info.Name, info.Namespace
+		mapping := info.ResourceMapping()
+		client, err := f.ClientForMapping(mapping)
+		if err != nil {
+			return err
+		}
+
+		helper := resource.NewHelper(client, mapping)
+		patchedObject, err := helper.Patch(namespace, name, patchType, patchBytes)
+		if err != nil {
+			return err
+		}
+		if cmdutil.ShouldRecord(cmd, info) {
+			if err := cmdutil.RecordChangeCause(patchedObject, f.Command()); err == nil {
+				// don't return an error on failure.  The patch itself succeeded, its only the hint for that change that failed
+				// don't bother checking for failures of this replace, because a failure to indicate the hint doesn't fail the command
+				// also, don't force the replacement.  If the replacement fails on a resourceVersion conflict, then it means this
+				// record hint is likely to be invalid anyway, so avoid the bad hint
+				resource.NewHelper(client, mapping).Replace(namespace, name, false, patchedObject)
+			}
+		}
+		count++
+		cmdutil.PrintSuccess(mapper, shortOutput, out, "", name, "patched")
+		return nil
+	})
+	if err != nil {
+		return err
+	}
+	if count == 0 {
+		return fmt.Errorf("no objects passed to patch")
 	}
-	cmdutil.PrintSuccess(mapper, shortOutput, out, "", name, "patched")
 	return nil
 }

pkg/kubectl/cmd/scale.go

@@ -27,7 +27,6 @@ import (
 	"k8s.io/kubernetes/pkg/kubectl"
 	cmdutil "k8s.io/kubernetes/pkg/kubectl/cmd/util"
 	"k8s.io/kubernetes/pkg/kubectl/resource"
-	utilerrors "k8s.io/kubernetes/pkg/util/errors"
 )
 
 // ScaleOptions is the start of the data required to perform the operation.  As new fields are added, add them here instead of
@@ -122,43 +121,47 @@ func RunScale(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, args []stri
 		return err
 	}
 
-	infos, err := r.Infos()
-	if err != nil {
-		return err
-	}
-	info := infos[0]
-	mapping := info.ResourceMapping()
-	scaler, err := f.Scaler(mapping)
-	if err != nil {
-		return err
-	}
+	infos := []*resource.Info{}
+	err = r.Visit(func(info *resource.Info, err error) error {
+		if err == nil {
+			infos = append(infos, info)
+		}
+		return nil
+	})
 
 	resourceVersion := cmdutil.GetFlagString(cmd, "resource-version")
 	if len(resourceVersion) != 0 && len(infos) > 1 {
 		return fmt.Errorf("cannot use --resource-version with multiple resources")
 	}
-	currentSize := cmdutil.GetFlagInt(cmd, "current-replicas")
-	if currentSize != -1 && len(infos) > 1 {
-		return fmt.Errorf("cannot use --current-replicas with multiple resources")
-	}
-	precondition := &kubectl.ScalePrecondition{Size: currentSize, ResourceVersion: resourceVersion}
-	retry := kubectl.NewRetryParams(kubectl.Interval, kubectl.Timeout)
-	var waitForReplicas *kubectl.RetryParams
-	if timeout := cmdutil.GetFlagDuration(cmd, "timeout"); timeout != 0 {
-		waitForReplicas = kubectl.NewRetryParams(kubectl.Interval, timeout)
-	}
 
-	errs := []error{}
-	for _, info := range infos {
+	counter := 0
+	err = r.Visit(func(info *resource.Info, err error) error {
+		if err != nil {
+			return err
+		}
+
+		mapping := info.ResourceMapping()
+		scaler, err := f.Scaler(mapping)
+		if err != nil {
+			return err
+		}
+
+		currentSize := cmdutil.GetFlagInt(cmd, "current-replicas")
+		precondition := &kubectl.ScalePrecondition{Size: currentSize, ResourceVersion: resourceVersion}
+		retry := kubectl.NewRetryParams(kubectl.Interval, kubectl.Timeout)
+
+		var waitForReplicas *kubectl.RetryParams
+		if timeout := cmdutil.GetFlagDuration(cmd, "timeout"); timeout != 0 {
+			waitForReplicas = kubectl.NewRetryParams(kubectl.Interval, timeout)
+		}
+
 		if err := scaler.Scale(info.Namespace, info.Name, uint(count), precondition, retry, waitForReplicas); err != nil {
-			errs = append(errs, err)
-			continue
+			return err
 		}
 		if cmdutil.ShouldRecord(cmd, info) {
 			patchBytes, err := cmdutil.ChangeResourcePatch(info, f.Command())
 			if err != nil {
-				errs = append(errs, err)
-				continue
+				return err
 			}
 			mapping := info.ResourceMapping()
 			client, err := f.ClientForMapping(mapping)
@@ -168,12 +171,18 @@ func RunScale(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, args []stri
 			helper := resource.NewHelper(client, mapping)
 			_, err = helper.Patch(info.Namespace, info.Name, api.StrategicMergePatchType, patchBytes)
 			if err != nil {
-				errs = append(errs, err)
-				continue
+				return err
 			}
 		}
+		counter++
 		cmdutil.PrintSuccess(mapper, shortOutput, out, info.Mapping.Resource, info.Name, "scaled")
+		return nil
+	})
+	if err != nil {
+		return err
 	}
-
-	return utilerrors.NewAggregate(errs)
+	if counter == 0 {
+		return fmt.Errorf("no objects passed to scale")
+	}
+	return nil
 }