Add `kubectl auth can-i --list` option which could help users know what actions…

pkg/kubectl/cmd/auth/BUILD

@@ -17,7 +17,10 @@ go_library(
     ],
     deps = [
         "//pkg/kubectl/cmd/util:go_default_library",
+        "//pkg/kubectl/describe/versioned:go_default_library",
         "//pkg/kubectl/scheme:go_default_library",
+        "//pkg/kubectl/util/printers:go_default_library",
+        "//pkg/kubectl/util/rbac:go_default_library",
         "//pkg/kubectl/util/templates:go_default_library",
         "//pkg/registry/rbac/reconciliation:go_default_library",
         "//staging/src/k8s.io/api/authorization/v1:go_default_library",
@@ -26,6 +29,7 @@ go_library(
         "//staging/src/k8s.io/api/rbac/v1beta1:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/api/meta:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/runtime/schema:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/util/errors:go_default_library",
         "//staging/src/k8s.io/cli-runtime/pkg/genericclioptions:go_default_library",
         "//staging/src/k8s.io/cli-runtime/pkg/genericclioptions/printers:go_default_library",
         "//staging/src/k8s.io/cli-runtime/pkg/genericclioptions/resource:go_default_library",
@@ -59,7 +63,10 @@ go_test(
     deps = [
         "//pkg/kubectl/cmd/testing:go_default_library",
         "//pkg/kubectl/scheme:go_default_library",
+        "//staging/src/k8s.io/api/authorization/v1:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/runtime:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/runtime/schema:go_default_library",
+        "//staging/src/k8s.io/cli-runtime/pkg/genericclioptions:go_default_library",
         "//staging/src/k8s.io/client-go/rest:go_default_library",
         "//staging/src/k8s.io/client-go/rest/fake:go_default_library",
     ],

pkg/kubectl/cmd/auth/cani.go

@@ -19,18 +19,25 @@ package auth
 import (
 	"errors"
 	"fmt"
+	"io"
 	"io/ioutil"
 	"os"
+	"sort"
 	"strings"
 
 	"github.com/spf13/cobra"
 
 	authorizationv1 "k8s.io/api/authorization/v1"
+	rbacv1 "k8s.io/api/rbac/v1"
 	"k8s.io/apimachinery/pkg/api/meta"
 	"k8s.io/apimachinery/pkg/runtime/schema"
+	utilerrors "k8s.io/apimachinery/pkg/util/errors"
 	"k8s.io/cli-runtime/pkg/genericclioptions"
 	authorizationv1client "k8s.io/client-go/kubernetes/typed/authorization/v1"
 	cmdutil "k8s.io/kubernetes/pkg/kubectl/cmd/util"
+	describeutil "k8s.io/kubernetes/pkg/kubectl/describe/versioned"
+	"k8s.io/kubernetes/pkg/kubectl/util/printers"
+	rbacutil "k8s.io/kubernetes/pkg/kubectl/util/rbac"
 	"k8s.io/kubernetes/pkg/kubectl/util/templates"
 )
 
@@ -39,14 +46,16 @@ import (
 type CanIOptions struct {
 	AllNamespaces bool
 	Quiet         bool
+	NoHeaders     bool
 	Namespace     string
-	SelfSARClient authorizationv1client.SelfSubjectAccessReviewsGetter
+	AuthClient    authorizationv1client.AuthorizationV1Interface
 
 	Verb           string
 	Resource       schema.GroupVersionResource
 	NonResourceURL string
 	Subresource    string
 	ResourceName   string
+	List           bool
 
 	genericclioptions.IOStreams
 }
@@ -77,7 +86,10 @@ var (
 		kubectl auth can-i get pods --subresource=log
 
 		# Check to see if I can access the URL /logs/
-		kubectl auth can-i get /logs/`)
+		kubectl auth can-i get /logs/
+
+		# List all allowed actions in namespace "foo"
+		kubectl auth can-i --list --namespace=foo`)
 )
 
 // NewCmdCanI returns an initialized Command for 'auth can-i' sub command
@@ -95,14 +107,18 @@ func NewCmdCanI(f cmdutil.Factory, streams genericclioptions.IOStreams) *cobra.C
 		Run: func(cmd *cobra.Command, args []string) {
 			cmdutil.CheckErr(o.Complete(f, args))
 			cmdutil.CheckErr(o.Validate())
-
-			allowed, err := o.RunAccessCheck()
-			if err == nil {
-				if !allowed {
-					os.Exit(1)
+			var err error
+			if o.List {
+				err = o.RunAccessList()
+			} else {
+				var allowed bool
+				allowed, err = o.RunAccessCheck()
+				if err == nil {
+					if !allowed {
+						os.Exit(1)
+					}
 				}
 			}
-
 			cmdutil.CheckErr(err)
 		},
 	}
@@ -110,33 +126,41 @@ func NewCmdCanI(f cmdutil.Factory, streams genericclioptions.IOStreams) *cobra.C
 	cmd.Flags().BoolVarP(&o.AllNamespaces, "all-namespaces", "A", o.AllNamespaces, "If true, check the specified action in all namespaces.")
 	cmd.Flags().BoolVarP(&o.Quiet, "quiet", "q", o.Quiet, "If true, suppress output and just return the exit code.")
 	cmd.Flags().StringVar(&o.Subresource, "subresource", o.Subresource, "SubResource such as pod/log or deployment/scale")
+	cmd.Flags().BoolVar(&o.List, "list", o.List, "If true, prints all allowed actions.")
+	cmd.Flags().BoolVar(&o.NoHeaders, "no-headers", o.NoHeaders, "If true, prints allowed actions without headers")
 	return cmd
 }
 
 // Complete completes all the required options
 func (o *CanIOptions) Complete(f cmdutil.Factory, args []string) error {
-	if o.Quiet {
-		o.Out = ioutil.Discard
-	}
-
-	switch len(args) {
-	case 2:
-		o.Verb = args[0]
-		if strings.HasPrefix(args[1], "/") {
-			o.NonResourceURL = args[1]
-			break
+	if o.List {
+		if len(args) != 0 {
+			return errors.New("list option must be specified with no arguments")
 		}
-		resourceTokens := strings.SplitN(args[1], "/", 2)
-		restMapper, err := f.ToRESTMapper()
-		if err != nil {
-			return err
+	} else {
+		if o.Quiet {
+			o.Out = ioutil.Discard
 		}
-		o.Resource = o.resourceFor(restMapper, resourceTokens[0])
-		if len(resourceTokens) > 1 {
-			o.ResourceName = resourceTokens[1]
+
+		switch len(args) {
+		case 2:
+			o.Verb = args[0]
+			if strings.HasPrefix(args[1], "/") {
+				o.NonResourceURL = args[1]
+				break
+			}
+			resourceTokens := strings.SplitN(args[1], "/", 2)
+			restMapper, err := f.ToRESTMapper()
+			if err != nil {
+				return err
+			}
+			o.Resource = o.resourceFor(restMapper, resourceTokens[0])
+			if len(resourceTokens) > 1 {
+				o.ResourceName = resourceTokens[1]
+			}
+		default:
+			return errors.New("you must specify two or three arguments: verb, resource, and optional resourceName")
 		}
-	default:
-		return errors.New("you must specify two or three arguments: verb, resource, and optional resourceName")
 	}
 
 	var err error
@@ -144,8 +168,7 @@ func (o *CanIOptions) Complete(f cmdutil.Factory, args []string) error {
 	if err != nil {
 		return err
 	}
-	o.SelfSARClient = client.AuthorizationV1()
-
+	o.AuthClient = client.AuthorizationV1()
 	o.Namespace = ""
 	if !o.AllNamespaces {
 		o.Namespace, _, err = f.ToRawKubeConfigLoader().Namespace()
@@ -159,6 +182,13 @@ func (o *CanIOptions) Complete(f cmdutil.Factory, args []string) error {
 
 // Validate makes sure provided values for CanIOptions are valid
 func (o *CanIOptions) Validate() error {
+	if o.List {
+		if o.Quiet || o.AllNamespaces || o.Subresource != "" {
+			return errors.New("list option can't be specified with neither quiet, all-namespaces nor subresource options")
+		}
+		return nil
+	}
+
 	if o.NonResourceURL != "" {
 		if o.Subresource != "" {
 			return fmt.Errorf("--subresource can not be used with NonResourceURL")
@@ -167,9 +197,28 @@ func (o *CanIOptions) Validate() error {
 			return fmt.Errorf("NonResourceURL and ResourceName can not specified together")
 		}
 	}
+
+	if o.NoHeaders {
+		return fmt.Errorf("--no-headers cannot be set without --list specified")
+	}
 	return nil
 }
 
+// RunAccessList lists all the access current user has
+func (o *CanIOptions) RunAccessList() error {
+	sar := &authorizationv1.SelfSubjectRulesReview{
+		Spec: authorizationv1.SelfSubjectRulesReviewSpec{
+			Namespace: o.Namespace,
+		},
+	}
+	response, err := o.AuthClient.SelfSubjectRulesReviews().Create(sar)
+	if err != nil {
+		return err
+	}
+
+	return o.printStatus(response.Status)
+}
+
 // RunAccessCheck checks if user has access to a certain resource or non resource URL
 func (o *CanIOptions) RunAccessCheck() (bool, error) {
 	var sar *authorizationv1.SelfSubjectAccessReview
@@ -195,10 +244,9 @@ func (o *CanIOptions) RunAccessCheck() (bool, error) {
 				},
 			},
 		}
-
 	}
 
-	response, err := o.SelfSARClient.SelfSubjectAccessReviews().Create(sar)
+	response, err := o.AuthClient.SelfSubjectAccessReviews().Create(sar)
 	if err != nil {
 		return false, err
 	}
@@ -244,3 +292,71 @@ func (o *CanIOptions) resourceFor(mapper meta.RESTMapper, resourceArg string) sc
 
 	return gvr
 }
+
+func (o *CanIOptions) printStatus(status authorizationv1.SubjectRulesReviewStatus) error {
+	if status.Incomplete {
+		fmt.Fprintf(o.ErrOut, "warning: the list may be incomplete: %v\n", status.EvaluationError)
+	}
+
+	breakdownRules := []rbacv1.PolicyRule{}
+	for _, rule := range convertToPolicyRule(status) {
+		breakdownRules = append(breakdownRules, rbacutil.BreakdownRule(rule)...)
+	}
+
+	compactRules, err := rbacutil.CompactRules(breakdownRules)
+	if err != nil {
+		return err
+	}
+	sort.Stable(rbacutil.SortableRuleSlice(compactRules))
+
+	w := printers.GetNewTabWriter(o.Out)
+	defer w.Flush()
+
+	allErrs := []error{}
+	if !o.NoHeaders {
+		if err := printAccessHeaders(w); err != nil {
+			allErrs = append(allErrs, err)
+		}
+	}
+
+	if err := printAccess(w, compactRules); err != nil {
+		allErrs = append(allErrs, err)
+	}
+	return utilerrors.NewAggregate(allErrs)
+}
+
+func convertToPolicyRule(status authorizationv1.SubjectRulesReviewStatus) []rbacv1.PolicyRule {
+	ret := []rbacv1.PolicyRule{}
+	for _, resource := range status.ResourceRules {
+		ret = append(ret, rbacv1.PolicyRule{
+			Verbs:         resource.Verbs,
+			APIGroups:     resource.APIGroups,
+			Resources:     resource.Resources,
+			ResourceNames: resource.ResourceNames,
+		})
+	}
+
+	for _, nonResource := range status.NonResourceRules {
+		ret = append(ret, rbacv1.PolicyRule{
+			Verbs:           nonResource.Verbs,
+			NonResourceURLs: nonResource.NonResourceURLs,
+		})
+	}
+
+	return ret
+}
+
+func printAccessHeaders(out io.Writer) error {
+	columnNames := []string{"Resources", "Non-Resource URLs", "Resource Names", "Verbs"}
+	_, err := fmt.Fprintf(out, "%s\n", strings.Join(columnNames, "\t"))
+	return err
+}
+
+func printAccess(out io.Writer, rules []rbacv1.PolicyRule) error {
+	for _, r := range rules {
+		if _, err := fmt.Fprintf(out, "%s\t%v\t%v\t%v\n", describeutil.CombineResourceGroup(r.Resources, r.APIGroups), r.NonResourceURLs, r.ResourceNames, r.Verbs); err != nil {
+			return err
+		}
+	}
+	return nil
+}

pkg/kubectl/cmd/auth/cani_test.go

@@ -24,7 +24,10 @@ import (
 	"strings"
 	"testing"
 
+	authorizationv1 "k8s.io/api/authorization/v1"
+	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/cli-runtime/pkg/genericclioptions"
 	restclient "k8s.io/client-go/rest"
 	"k8s.io/client-go/rest/fake"
 	cmdtesting "k8s.io/kubernetes/pkg/kubectl/cmd/testing"
@@ -181,3 +184,69 @@ func TestRunAccessCheck(t *testing.T) {
 		})
 	}
 }
+
+func TestRunAccessList(t *testing.T) {
+	t.Run("test access list", func(t *testing.T) {
+		options := &CanIOptions{List: true}
+		expectedOutput := "Resources   Non-Resource URLs   Resource Names    Verbs\n" +
+			"job.*       []                  [test-resource]   [get list]\n" +
+			"pod.*       []                  [test-resource]   [get list]\n" +
+			"            [/apis/*]           []                [get]\n" +
+			"            [/version]          []                [get]\n"
+
+		tf := cmdtesting.NewTestFactory().WithNamespace("test")
+		defer tf.Cleanup()
+
+		ns := scheme.Codecs
+		codec := scheme.Codecs.LegacyCodec(scheme.Scheme.PrioritizedVersionsAllGroups()...)
+
+		tf.Client = &fake.RESTClient{
+			GroupVersion:         schema.GroupVersion{Group: "", Version: "v1"},
+			NegotiatedSerializer: ns,
+			Client: fake.CreateHTTPClient(func(req *http.Request) (*http.Response, error) {
+				switch req.URL.Path {
+				case "/apis/authorization.k8s.io/v1/selfsubjectrulesreviews":
+					body := ioutil.NopCloser(bytes.NewReader([]byte(runtime.EncodeOrDie(codec, getSelfSubjectRulesReview()))))
+					return &http.Response{StatusCode: http.StatusOK, Body: body}, nil
+				default:
+					t.Fatalf("unexpected request: %#v\n%#v", req.URL, req)
+					return nil, nil
+				}
+			}),
+		}
+		ioStreams, _, buf, _ := genericclioptions.NewTestIOStreams()
+		options.IOStreams = ioStreams
+		if err := options.Complete(tf, []string{}); err != nil {
+			t.Errorf("got unexpected error when do Complete(): %v", err)
+			return
+		}
+
+		err := options.RunAccessList()
+		if err != nil {
+			t.Errorf("got unexpected error when do RunAccessList(): %v", err)
+		} else if buf.String() != expectedOutput {
+			t.Errorf("expected %v\n but got %v\n", expectedOutput, buf.String())
+		}
+	})
+}
+
+func getSelfSubjectRulesReview() *authorizationv1.SelfSubjectRulesReview {
+	return &authorizationv1.SelfSubjectRulesReview{
+		Status: authorizationv1.SubjectRulesReviewStatus{
+			ResourceRules: []authorizationv1.ResourceRule{
+				{
+					Verbs:         []string{"get", "list"},
+					APIGroups:     []string{"*"},
+					Resources:     []string{"pod", "job"},
+					ResourceNames: []string{"test-resource"},
+				},
+			},
+			NonResourceRules: []authorizationv1.NonResourceRule{
+				{
+					Verbs:           []string{"get"},
+					NonResourceURLs: []string{"/apis/*", "/version"},
+				},
+			},
+		},
+	}
+}

pkg/kubectl/describe/versioned/describe.go

@@ -2677,7 +2677,7 @@ func (d *RoleDescriber) Describe(namespace, name string, describerSettings descr
 		w.Write(LEVEL_1, "Resources\tNon-Resource URLs\tResource Names\tVerbs\n")
 		w.Write(LEVEL_1, "---------\t-----------------\t--------------\t-----\n")
 		for _, r := range compactRules {
-			w.Write(LEVEL_1, "%s\t%v\t%v\t%v\n", combineResourceGroup(r.Resources, r.APIGroups), r.NonResourceURLs, r.ResourceNames, r.Verbs)
+			w.Write(LEVEL_1, "%s\t%v\t%v\t%v\n", CombineResourceGroup(r.Resources, r.APIGroups), r.NonResourceURLs, r.ResourceNames, r.Verbs)
 		}
 
 		return nil
@@ -2716,14 +2716,14 @@ func (d *ClusterRoleDescriber) Describe(namespace, name string, describerSetting
 		w.Write(LEVEL_1, "Resources\tNon-Resource URLs\tResource Names\tVerbs\n")
 		w.Write(LEVEL_1, "---------\t-----------------\t--------------\t-----\n")
 		for _, r := range compactRules {
-			w.Write(LEVEL_1, "%s\t%v\t%v\t%v\n", combineResourceGroup(r.Resources, r.APIGroups), r.NonResourceURLs, r.ResourceNames, r.Verbs)
+			w.Write(LEVEL_1, "%s\t%v\t%v\t%v\n", CombineResourceGroup(r.Resources, r.APIGroups), r.NonResourceURLs, r.ResourceNames, r.Verbs)
 		}
 
 		return nil
 	})
 }
 
-func combineResourceGroup(resource, group []string) string {
+func CombineResourceGroup(resource, group []string) string {
 	if len(resource) == 0 {
 		return ""
 	}