Merge pull request #41146 from shiywang/apply-view1

Automatic merge from submit-queue (batch tested with PRs 41146, 41486, 41482, 41538, 41784)

 Add apply view-last-applied subcommand

reopen pr https://github.com/kubernetes/kubernetes/pull/40984, implement part of https://github.com/kubernetes/community/pull/287
for now unit test all pass, the output looks like:

```console
shiywang@dhcp-140-33 template $ ./kubectl apply view last-applied deployment nginx-deployment 
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  creationTimestamp: null
  name: nginx-deployment
spec:
  strategy: {}
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: nginx
    spec:
      containers:
      - image: nginx:1.12.10
        name: nginx
        ports:
        - containerPort: 80
        resources: {}
status: {}
```

```release-note
Support new kubectl apply view-last-applied command for viewing the last configuration file applied
```

not sure if there is any flag I should updated or the some error handling I should changed.
will generate docs when you guys think is ok.
cc @pwittrock @jessfraz @AdoHe @ymqytw

docs/.generated_docs

@@ -12,6 +12,7 @@ docs/man/man1/kube-proxy.1
 docs/man/man1/kube-scheduler.1
 docs/man/man1/kubectl-annotate.1
 docs/man/man1/kubectl-api-versions.1
+docs/man/man1/kubectl-apply-view-last-applied.1
 docs/man/man1/kubectl-apply.1
 docs/man/man1/kubectl-attach.1
 docs/man/man1/kubectl-autoscale.1
@@ -97,6 +98,7 @@ docs/user-guide/kubectl/kubectl.md
 docs/user-guide/kubectl/kubectl_annotate.md
 docs/user-guide/kubectl/kubectl_api-versions.md
 docs/user-guide/kubectl/kubectl_apply.md
+docs/user-guide/kubectl/kubectl_apply_view-last-applied.md
 docs/user-guide/kubectl/kubectl_attach.md
 docs/user-guide/kubectl/kubectl_autoscale.md
 docs/user-guide/kubectl/kubectl_certificate.md

docs/man/man1/kubectl-apply-view-last-applied.1

@@ -0,0 +1,3 @@
+This file is autogenerated, but we've stopped checking such files into the
+repository to reduce the need for rebases. Please run hack/generate-docs.sh to
+populate this file.

docs/user-guide/kubectl/kubectl_apply_view-last-applied.md

@@ -0,0 +1,3 @@
+This file is autogenerated, but we've stopped checking such files into the
+repository to reduce the need for rebases. Please run hack/generate-docs.sh to
+populate this file.

pkg/kubectl/cmd/BUILD

@@ -14,6 +14,7 @@ go_library(
         "annotate.go",
         "apiversions.go",
         "apply.go",
+        "apply_view_last_applied.go",
         "attach.go",
         "autoscale.go",
         "certificates.go",
@@ -98,6 +99,7 @@ go_library(
         "//vendor:github.com/docker/distribution/reference",
         "//vendor:github.com/docker/docker/pkg/term",
         "//vendor:github.com/evanphx/json-patch",
+        "//vendor:github.com/ghodss/yaml",
         "//vendor:github.com/golang/glog",
         "//vendor:github.com/jonboulle/clockwork",
         "//vendor:github.com/renstrom/dedent",

pkg/kubectl/cmd/apply.go

@@ -128,6 +128,10 @@ func NewCmdApply(f cmdutil.Factory, out, errOut io.Writer) *cobra.Command {
 	cmdutil.AddPrinterFlags(cmd)
 	cmdutil.AddRecordFlag(cmd)
 	cmdutil.AddInclude3rdPartyFlags(cmd)
+
+	// apply subcommands
+	cmd.AddCommand(NewCmdApplyViewLastApplied(f, out, errOut))
+
 	return cmd
 }
 

pkg/kubectl/cmd/apply_test.go

@@ -59,9 +59,10 @@ func validateApplyArgs(cmd *cobra.Command, args []string) error {
 }
 
 const (
-	filenameRC    = "../../../test/fixtures/pkg/kubectl/cmd/apply/rc.yaml"
+	filenameRC            = "../../../test/fixtures/pkg/kubectl/cmd/apply/rc.yaml"
-	filenameSVC   = "../../../test/fixtures/pkg/kubectl/cmd/apply/service.yaml"
+	filenameRCLASTAPPLIED = "../../../test/fixtures/pkg/kubectl/cmd/apply/rc-lastapplied.yaml"
-	filenameRCSVC = "../../../test/fixtures/pkg/kubectl/cmd/apply/rc-service.yaml"
+	filenameSVC           = "../../../test/fixtures/pkg/kubectl/cmd/apply/service.yaml"
+	filenameRCSVC         = "../../../test/fixtures/pkg/kubectl/cmd/apply/rc-service.yaml"
 )
 
 func readBytesFromFile(t *testing.T, filename string) []byte {
@@ -193,6 +194,129 @@ func walkMapPath(t *testing.T, start map[string]interface{}, path []string) map[
 	return finish
 }
 
+func TestRunApplyViewLastApplied(t *testing.T) {
+	_, rcBytesWithConfig := readReplicationController(t, filenameRCLASTAPPLIED)
+	nameRC, rcBytes := readReplicationController(t, filenameRC)
+	pathRC := "/namespaces/test/replicationcontrollers/" + nameRC
+
+	tests := []struct {
+		name, nameRC, pathRC, filePath, outputFormat, expectedErr, expectedOut, selector string
+		args                                                                             []string
+		respBytes                                                                        []byte
+	}{
+		{
+			name:         "view with file",
+			filePath:     filenameRC,
+			outputFormat: "",
+			expectedErr:  "",
+			expectedOut:  "test: 1234\n",
+			selector:     "",
+			args:         []string{},
+			respBytes:    rcBytesWithConfig,
+		},
+		{
+			name:         "view with file json format",
+			filePath:     filenameRC,
+			outputFormat: "json",
+			expectedErr:  "",
+			expectedOut:  "{\n  \"test\": 1234\n}\n",
+			selector:     "",
+			args:         []string{},
+			respBytes:    rcBytesWithConfig,
+		},
+		{
+			name:         "view resource/name invalid format",
+			filePath:     "",
+			outputFormat: "wide",
+			expectedErr:  "error: Unexpected -o output mode: wide, the flag 'output' must be one of yaml|json\nSee 'view-last-applied -h' for help and examples.",
+			expectedOut:  "",
+			selector:     "",
+			args:         []string{"rc", "test-rc"},
+			respBytes:    rcBytesWithConfig,
+		},
+		{
+			name:         "view resource with label",
+			filePath:     "",
+			outputFormat: "",
+			expectedErr:  "",
+			expectedOut:  "test: 1234\n",
+			selector:     "name=test-rc",
+			args:         []string{"rc"},
+			respBytes:    rcBytesWithConfig,
+		},
+		{
+			name:         "view resource without annotations",
+			filePath:     "",
+			outputFormat: "",
+			expectedErr:  "error: no last-applied-configuration annotation found on resource: test-rc",
+			expectedOut:  "",
+			selector:     "",
+			args:         []string{"rc", "test-rc"},
+			respBytes:    rcBytes,
+		},
+		{
+			name:         "view resource no match",
+			filePath:     "",
+			outputFormat: "",
+			expectedErr:  "Error from server (NotFound): the server could not find the requested resource (get replicationcontrollers no-match)",
+			expectedOut:  "",
+			selector:     "",
+			args:         []string{"rc", "no-match"},
+			respBytes:    nil,
+		},
+	}
+	for _, test := range tests {
+		f, tf, codec, _ := cmdtesting.NewAPIFactory()
+		tf.Printer = &testPrinter{}
+		tf.UnstructuredClient = &fake.RESTClient{
+			APIRegistry:          api.Registry,
+			NegotiatedSerializer: unstructuredSerializer,
+			Client: fake.CreateHTTPClient(func(req *http.Request) (*http.Response, error) {
+				switch p, m := req.URL.Path, req.Method; {
+				case p == pathRC && m == "GET":
+					bodyRC := ioutil.NopCloser(bytes.NewReader(test.respBytes))
+					return &http.Response{StatusCode: 200, Header: defaultHeader(), Body: bodyRC}, nil
+				case p == "/namespaces/test/replicationcontrollers" && m == "GET":
+					bodyRC := ioutil.NopCloser(bytes.NewReader(test.respBytes))
+					return &http.Response{StatusCode: 200, Header: defaultHeader(), Body: bodyRC}, nil
+				case p == "/namespaces/test/replicationcontrollers/no-match" && m == "GET":
+					return &http.Response{StatusCode: 404, Header: defaultHeader(), Body: objBody(codec, &api.Pod{})}, nil
+				case p == "/api/v1/namespaces/test" && m == "GET":
+					return &http.Response{StatusCode: 200, Header: defaultHeader(), Body: objBody(codec, &api.Namespace{})}, nil
+				default:
+					t.Fatalf("unexpected request: %#v\n%#v", req.URL, req)
+					return nil, nil
+				}
+			}),
+		}
+		tf.Namespace = "test"
+		tf.ClientConfig = defaultClientConfig()
+		buf, errBuf := bytes.NewBuffer([]byte{}), bytes.NewBuffer([]byte{})
+
+		cmdutil.BehaviorOnFatal(func(str string, code int) {
+			if str != test.expectedErr {
+				t.Errorf("%s: unexpected error: %s\nexpected: %s", test.name, str, test.expectedErr)
+			}
+		})
+
+		cmd := NewCmdApplyViewLastApplied(f, buf, errBuf)
+		if test.filePath != "" {
+			cmd.Flags().Set("filename", test.filePath)
+		}
+		if test.outputFormat != "" {
+			cmd.Flags().Set("output", test.outputFormat)
+		}
+		if test.selector != "" {
+			cmd.Flags().Set("selector", test.selector)
+		}
+
+		cmd.Run(cmd, test.args)
+		if buf.String() != test.expectedOut {
+			t.Fatalf("%s: unexpected output: %s\nexpected: %s", test.name, buf.String(), test.expectedOut)
+		}
+	}
+}
+
 func TestApplyObjectWithoutAnnotation(t *testing.T) {
 	initTestErrorHandler(t)
 	nameRC, rcBytes := readReplicationController(t, filenameRC)

pkg/kubectl/cmd/apply_view_last_applied.go

@@ -0,0 +1,165 @@
+/*
+Copyright 2017 The Kubernetes Authors.
+
+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 (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+
+	"github.com/ghodss/yaml"
+	"github.com/spf13/cobra"
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+	"k8s.io/kubernetes/pkg/kubectl"
+	"k8s.io/kubernetes/pkg/kubectl/cmd/templates"
+	cmdutil "k8s.io/kubernetes/pkg/kubectl/cmd/util"
+	"k8s.io/kubernetes/pkg/kubectl/resource"
+)
+
+type ViewLastAppliedOptions struct {
+	FilenameOptions              resource.FilenameOptions
+	Selector                     string
+	LastAppliedConfigurationList []string
+	OutputFormat                 string
+	Factory                      cmdutil.Factory
+	Out                          io.Writer
+	ErrOut                       io.Writer
+}
+
+var (
+	applyViewLastAppliedLong = templates.LongDesc(`
+		View the latest last-applied-configuration annotations by type/name or file.
+
+		The default output will be printed to stdout in YAML format. One can use -o option
+		to change output format.`)
+
+	applyViewLastAppliedExample = templates.Examples(`
+		# View the last-applied-configuration annotations by type/name in YAML.
+		kubectl apply view-last-applied deployment/nginx
+
+		# View the last-applied-configuration annotations by file in JSON
+		kubectl apply view-last-applied -f deploy.yaml -o json`)
+)
+
+func NewCmdApplyViewLastApplied(f cmdutil.Factory, out, err io.Writer) *cobra.Command {
+	options := &ViewLastAppliedOptions{Out: out, ErrOut: err}
+	cmd := &cobra.Command{
+		Use:     "view-last-applied (TYPE [NAME | -l label] | TYPE/NAME | -f FILENAME)",
+		Short:   "View latest last-applied-configuration annotations of a resource/object",
+		Long:    applyViewLastAppliedLong,
+		Example: applyViewLastAppliedExample,
+		Run: func(cmd *cobra.Command, args []string) {
+			cmdutil.CheckErr(options.ValidateOutputArgs(cmd))
+			cmdutil.CheckErr(options.Complete(f, args))
+			cmdutil.CheckErr(options.Validate(cmd))
+			cmdutil.CheckErr(options.RunApplyViewLastApplied())
+		},
+	}
+
+	cmd.Flags().StringP("output", "o", "", "Output format. Must be one of yaml|json")
+	cmd.Flags().StringVarP(&options.Selector, "selector", "l", "", "Selector (label query) to filter on, supports '=', '==', and '!='.")
+	usage := "that contains the last-applied-configuration annotations"
+	cmdutil.AddFilenameOptionFlags(cmd, &options.FilenameOptions, usage)
+
+	return cmd
+}
+
+func (o *ViewLastAppliedOptions) Complete(f cmdutil.Factory, args []string) error {
+	mapper, typer, err := f.UnstructuredObject()
+	if err != nil {
+		return err
+	}
+
+	cmdNamespace, enforceNamespace, err := f.DefaultNamespace()
+	if err != nil {
+		return err
+	}
+
+	r := resource.NewBuilder(mapper, typer, resource.ClientMapperFunc(f.UnstructuredClientForMapping), unstructured.UnstructuredJSONScheme).
+		NamespaceParam(cmdNamespace).DefaultNamespace().
+		FilenameParam(enforceNamespace, &o.FilenameOptions).
+		ResourceTypeOrNameArgs(enforceNamespace, args...).
+		SelectorParam(o.Selector).
+		Latest().
+		Flatten().
+		Do()
+	err = r.Err()
+	if err != nil {
+		return err
+	}
+
+	err = r.Visit(func(info *resource.Info, err error) error {
+		if err != nil {
+			return err
+		}
+
+		configString, err := kubectl.GetOriginalConfiguration(info.Mapping, info.Object)
+		if err != nil {
+			return err
+		}
+		if configString == nil {
+			return cmdutil.AddSourceToErr(fmt.Sprintf("no last-applied-configuration annotation found on resource: %s\n", info.Name), info.Source, err)
+		}
+		o.LastAppliedConfigurationList = append(o.LastAppliedConfigurationList, string(configString))
+		return nil
+	})
+
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (o *ViewLastAppliedOptions) Validate(cmd *cobra.Command) error {
+	return nil
+}
+
+func (o *ViewLastAppliedOptions) RunApplyViewLastApplied() error {
+	for _, str := range o.LastAppliedConfigurationList {
+		yamlOutput, err := yaml.JSONToYAML([]byte(str))
+		switch o.OutputFormat {
+		case "json":
+			jsonBuffer := &bytes.Buffer{}
+			err = json.Indent(jsonBuffer, []byte(str), "", "  ")
+			if err != nil {
+				return err
+			}
+			fmt.Fprintf(o.Out, string(jsonBuffer.Bytes()))
+		case "yaml":
+			fmt.Fprintf(o.Out, string(yamlOutput))
+		}
+	}
+
+	return nil
+}
+
+func (o *ViewLastAppliedOptions) ValidateOutputArgs(cmd *cobra.Command) error {
+	format := cmdutil.GetFlagString(cmd, "output")
+	switch format {
+	case "json":
+		o.OutputFormat = "json"
+		return nil
+	// If flag -o is not specified, use yaml as default
+	case "yaml", "":
+		o.OutputFormat = "yaml"
+		return nil
+	default:
+		return cmdutil.UsageError(cmd, "Unexpected -o output mode: %s, the flag 'output' must be one of yaml|json", format)
+	}
+}

test/fixtures/pkg/kubectl/cmd/apply/rc-lastapplied.yaml

@@ -0,0 +1,21 @@
+apiVersion: v1
+kind: ReplicationController
+metadata:
+  annotations:
+    kubectl.kubernetes.io/last-applied-configuration: |
+      {"test":1234}
+  name: test-rc
+  labels:
+    name: test-rc
+spec:
+  replicas: 1
+  template:
+    metadata:
+      labels:
+        name: test-rc
+    spec:
+      containers:
+        - name: test-rc
+          image: nginx
+          ports:
+          - containerPort: 80