Merge pull request #3723 from jlowdermilk/kubectl-stop

Add a kubectl stop command

docs/kubectl.md

@@ -394,6 +394,7 @@ Additional help topics:
   kubectl rollingupdate Perform a rolling update of the given ReplicationController
   kubectl resize        Set a new size for a resizable resource (currently only Replication Controllers)
   kubectl run-container Run a particular image on the cluster.
+  kubectl stop          Gracefully shutdown a resource
 
 Use "kubectl help [command]" for more information about that command.
 ```
@@ -933,3 +934,46 @@ Usage:
 
 ```
 
+#### stop
+Gracefully shutdown a resource
+
+Attempts to shutdown and delete a resource that supports graceful termination.
+If the resource is resizable it will be resized to 0 before deletion.
+
+Examples:
+  $ kubectl stop replicationcontroller foo
+  foo stopped
+
+
+Usage:
+```
+  kubectl stop <resource> <id> [flags]
+
+ Available Flags:
+      --alsologtostderr=false: log to standard error as well as files
+      --api-version="": The API version to use when talking to the server
+  -a, --auth-path="": Path to the auth info file. If missing, prompt the user. Only used if using https.
+      --certificate-authority="": Path to a cert. file for the certificate authority.
+      --client-certificate="": Path to a client key file for TLS.
+      --client-key="": Path to a client key file for TLS.
+      --cluster="": The name of the kubeconfig cluster to use
+      --context="": The name of the kubeconfig context to use
+      --insecure-skip-tls-verify=false: If true, the server's certificate will not be checked for validity. This will make your HTTPS connections insecure.
+      --kubeconfig="": Path to the kubeconfig file to use for CLI requests.
+      --log_backtrace_at=:0: when logging hits line file:N, emit a stack trace
+      --log_dir=: If non-empty, write log files in this directory
+      --log_flush_frequency=5s: Maximum number of seconds between log flushes
+      --logtostderr=true: log to standard error instead of files
+      --match-server-version=false: Require server version to match client version
+      --namespace="": If present, the namespace scope for this CLI request.
+      --ns-path="": Path to the namespace info file that holds the namespace context to use for CLI requests.
+  -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.
+      --user="": The name of the kubeconfig user to use
+      --v=0: log level for V logs
+      --validate=false: If true, use a schema to validate the input before sending it
+      --vmodule=: comma-separated list of pattern=N settings for file-filtered logging
+
+```
+

pkg/kubectl/cmd/cmd.go

@@ -64,6 +64,8 @@ type Factory struct {
 	Printer func(cmd *cobra.Command, mapping *meta.RESTMapping, noHeaders bool) (kubectl.ResourcePrinter, error)
 	// Returns a Resizer for changing the size of the specified RESTMapping type or an error
 	Resizer func(cmd *cobra.Command, mapping *meta.RESTMapping) (kubectl.Resizer, error)
+	// Returns a Reaper for gracefully shutting down resources.
+	Reaper func(cmd *cobra.Command, mapping *meta.RESTMapping) (kubectl.Reaper, error)
 	// Returns a schema that can validate objects stored on disk.
 	Validator func(*cobra.Command) (validation.Schema, error)
 	// Returns the default namespace to use in cases where no other namespace is specified
@@ -131,11 +133,14 @@ func NewFactory(optionalClientConfig clientcmd.ClientConfig) *Factory {
 			if err != nil {
 				return nil, err
 			}
-			resizer, ok := kubectl.ResizerFor(mapping.Kind, client)
+			return kubectl.ResizerFor(mapping.Kind, client)
-			if !ok {
+		},
-				return nil, fmt.Errorf("no resizer has been implemented for %q", mapping.Kind)
+		Reaper: func(cmd *cobra.Command, mapping *meta.RESTMapping) (kubectl.Reaper, error) {
+			client, err := clients.ClientForVersion(mapping.APIVersion)
+			if err != nil {
+				return nil, err
 			}
-			return resizer, nil
+			return kubectl.ReaperFor(mapping.Kind, client)
 		},
 		Validator: func(cmd *cobra.Command) (validation.Schema, error) {
 			if GetFlagBool(cmd, "validate") {
@@ -206,6 +211,7 @@ Find more information at https://github.com/GoogleCloudPlatform/kubernetes.`,
 	cmds.AddCommand(f.NewCmdResize(out))
 
 	cmds.AddCommand(f.NewCmdRunContainer(out))
+	cmds.AddCommand(f.NewCmdStop(out))
 
 	return cmds
 }

pkg/kubectl/cmd/stop.go

@@ -0,0 +1,56 @@
+/*
+Copyright 2014 Google Inc. All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package cmd
+
+import (
+	"fmt"
+	"io"
+
+	"github.com/spf13/cobra"
+)
+
+func (f *Factory) NewCmdStop(out io.Writer) *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "stop <resource> <id>",
+		Short: "Gracefully shutdown a resource",
+		Long: `Gracefully shutdown a resource
+
+Attempts to shutdown and delete a resource that supports graceful termination.
+If the resource is resizable it will be resized to 0 before deletion.
+
+Examples:
+  $ kubectl stop replicationcontroller foo
+  foo stopped
+`,
+		Run: func(cmd *cobra.Command, args []string) {
+			if len(args) != 2 {
+				usageError(cmd, "<resource> <id>")
+			}
+			cmdNamespace, err := f.DefaultNamespace(cmd)
+			mapper, _ := f.Object(cmd)
+			mapping, namespace, name := ResourceFromArgs(cmd, args, mapper, cmdNamespace)
+
+			reaper, err := f.Reaper(cmd, mapping)
+			checkErr(err)
+
+			s, err := reaper.Stop(namespace, name)
+			checkErr(err)
+			fmt.Fprintf(out, "%s\n", s)
+		},
+	}
+	return cmd
+}

pkg/kubectl/resize.go

@@ -58,12 +58,12 @@ type Resizer interface {
 	Resize(namespace, name string, preconditions *ResizePrecondition, newSize uint) (string, error)
 }
 
-func ResizerFor(kind string, c *client.Client) (Resizer, bool) {
+func ResizerFor(kind string, c client.Interface) (Resizer, error) {
 	switch kind {
 	case "ReplicationController":
-		return &ReplicationControllerResizer{c}, true
+		return &ReplicationControllerResizer{c}, nil
 	}
-	return nil, false
+	return nil, fmt.Errorf("no resizer has been implemented for %q", kind)
 }
 
 type ReplicationControllerResizer struct {

pkg/kubectl/rolling_updater_test.go

@@ -26,18 +26,18 @@ import (
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/client"
 )
 
-type customFake struct {
+type updaterFake struct {
 	*client.Fake
 	ctrl client.ReplicationControllerInterface
 }
 
-func (c *customFake) ReplicationControllers(namespace string) client.ReplicationControllerInterface {
+func (c *updaterFake) ReplicationControllers(namespace string) client.ReplicationControllerInterface {
 	return c.ctrl
 }
 
 func fakeClientFor(namespace string, responses []fakeResponse) client.Interface {
 	fake := client.Fake{}
-	return &customFake{
+	return &updaterFake{
 		&fake,
 		&fakeRc{
 			&client.FakeReplicationControllers{

pkg/kubectl/stop.go

@@ -0,0 +1,110 @@
+/*
+Copyright 2014 Google Inc. All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package kubectl
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/api/meta"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/client"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/util/wait"
+)
+
+const (
+	interval = time.Second * 3
+	timeout  = time.Minute * 5
+)
+
+// A Reaper handles terminating an object as gracefully as possible.
+type Reaper interface {
+	Stop(namespace, name string) (string, error)
+}
+
+func ReaperFor(kind string, c client.Interface) (Reaper, error) {
+	switch kind {
+	case "ReplicationController":
+		return &ReplicationControllerReaper{c, interval, timeout}, nil
+	case "Pod":
+		return &PodReaper{c}, nil
+	case "Service":
+		return &ServiceReaper{c}, nil
+	}
+	return nil, fmt.Errorf("no reaper has been implemented for %q", kind)
+}
+
+type ReplicationControllerReaper struct {
+	client.Interface
+	pollInterval, timeout time.Duration
+}
+type PodReaper struct {
+	client.Interface
+}
+type ServiceReaper struct {
+	client.Interface
+}
+
+type objInterface interface {
+	Delete(name string) error
+	Get(name string) (meta.Interface, error)
+}
+
+func (reaper *ReplicationControllerReaper) Stop(namespace, name string) (string, error) {
+	rc := reaper.ReplicationControllers(namespace)
+	controller, err := rc.Get(name)
+	if err != nil {
+		return "", err
+	}
+
+	controller.Spec.Replicas = 0
+	// TODO: do retry on 409 errors here?
+	if _, err := rc.Update(controller); err != nil {
+		return "", err
+	}
+	if err := wait.Poll(reaper.pollInterval, reaper.timeout,
+		client.ControllerHasDesiredReplicas(reaper, controller)); err != nil {
+		return "", err
+	}
+	if err := rc.Delete(name); err != nil {
+		return "", err
+	}
+	return fmt.Sprintf("%s stopped", name), nil
+}
+
+func (reaper *PodReaper) Stop(namespace, name string) (string, error) {
+	pods := reaper.Pods(namespace)
+	_, err := pods.Get(name)
+	if err != nil {
+		return "", err
+	}
+	if err := pods.Delete(name); err != nil {
+		return "", err
+	}
+	return fmt.Sprintf("%s stopped", name), nil
+}
+
+func (reaper *ServiceReaper) Stop(namespace, name string) (string, error) {
+	services := reaper.Services(namespace)
+	_, err := services.Get(name)
+	if err != nil {
+		return "", err
+	}
+	if err := services.Delete(name); err != nil {
+		return "", err
+	}
+	return fmt.Sprintf("%s stopped", name), nil
+}

pkg/kubectl/stop_test.go

@@ -0,0 +1,168 @@
+/*
+Copyright 2014 Google Inc. All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package kubectl
+
+import (
+	"fmt"
+	"testing"
+	"time"
+
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/client"
+)
+
+func TestReplicationControllerStop(t *testing.T) {
+	fake := &client.Fake{
+		Ctrl: api.ReplicationController{
+			Spec: api.ReplicationControllerSpec{
+				Replicas: 0,
+			},
+		},
+	}
+	reaper := ReplicationControllerReaper{fake, time.Millisecond, time.Millisecond}
+	name := "foo"
+	s, err := reaper.Stop("default", name)
+	if err != nil {
+		t.Errorf("unexpected error: %v", err)
+	}
+	expected := "foo stopped"
+	if s != expected {
+		t.Errorf("expected %s, got %s", expected, s)
+	}
+	if len(fake.Actions) != 4 {
+		t.Errorf("unexpected actions: %v, expected 4 actions (get, update, get, delete)", fake.Actions)
+	}
+	for i, action := range []string{"get", "update", "get", "delete"} {
+		if fake.Actions[i].Action != action+"-controller" {
+			t.Errorf("unexpected action: %v, expected %s-controller", fake.Actions[i], action)
+		}
+	}
+}
+
+type noSuchPod struct {
+	*client.FakePods
+}
+
+func (c *noSuchPod) Get(name string) (*api.Pod, error) {
+	return nil, fmt.Errorf("%s does not exist", name)
+}
+
+type noDeleteService struct {
+	*client.FakeServices
+}
+
+func (c *noDeleteService) Delete(service string) error {
+	return fmt.Errorf("I'm afraid I can't do that, Dave")
+}
+
+type reaperFake struct {
+	*client.Fake
+	noSuchPod, noDeleteService bool
+}
+
+func (c *reaperFake) Pods(namespace string) client.PodInterface {
+	pods := &client.FakePods{c.Fake, namespace}
+	if c.noSuchPod {
+		return &noSuchPod{pods}
+	}
+	return pods
+}
+
+func (c *reaperFake) Services(namespace string) client.ServiceInterface {
+	services := &client.FakeServices{c.Fake, namespace}
+	if c.noDeleteService {
+		return &noDeleteService{services}
+	}
+	return services
+}
+
+func TestSimpleStop(t *testing.T) {
+	tests := []struct {
+		fake        *reaperFake
+		kind        string
+		actions     []string
+		expectError bool
+		test        string
+	}{
+		{
+			fake: &reaperFake{
+				Fake: &client.Fake{},
+			},
+			kind:        "Pod",
+			actions:     []string{"get-pod", "delete-pod"},
+			expectError: false,
+			test:        "stop pod succeeds",
+		},
+		{
+			fake: &reaperFake{
+				Fake: &client.Fake{},
+			},
+			kind:        "Service",
+			actions:     []string{"get-service", "delete-service"},
+			expectError: false,
+			test:        "stop service succeeds",
+		},
+		{
+			fake: &reaperFake{
+				Fake:      &client.Fake{},
+				noSuchPod: true,
+			},
+			kind:        "Pod",
+			actions:     []string{},
+			expectError: true,
+			test:        "stop pod fails, no pod",
+		},
+		{
+			fake: &reaperFake{
+				Fake:            &client.Fake{},
+				noDeleteService: true,
+			},
+			kind:        "Service",
+			actions:     []string{"get-service"},
+			expectError: true,
+			test:        "stop service fails, can't delete",
+		},
+	}
+	for _, test := range tests {
+		fake := test.fake
+		reaper, err := ReaperFor(test.kind, fake)
+		if err != nil {
+			t.Errorf("unexpected error: %v (%s)", err, test.test)
+		}
+		s, err := reaper.Stop("default", "foo")
+		if err != nil && !test.expectError {
+			t.Errorf("unexpected error: %v (%s)", err, test.test)
+		}
+		if err == nil {
+			if test.expectError {
+				t.Errorf("unexpected non-error: %v (%s)", err, test.test)
+			}
+			if s != "foo stopped" {
+				t.Errorf("unexpected return: %s (%s)", s, test.test)
+			}
+		}
+		if len(test.actions) != len(fake.Actions) {
+			t.Errorf("unexpected actions: %v; expected %v (%s)", fake.Actions, test.actions, test.test)
+		}
+		for i, action := range fake.Actions {
+			testAction := test.actions[i]
+			if action.Action != testAction {
+				t.Errorf("unexpected action: %v; expected %v (%s)", action, testAction, test.test)
+			}
+		}
+	}
+}