Merge pull request #46326 from xilabao/add-role-to-describe-command

Automatic merge from submit-queue (batch tested with PRs 46432, 46701, 46326, 40848, 46396)

add role/clusterrole to describe.go

**What this PR does / why we need it**:
```
# ./cluster/kubectl.sh describe clusterrole system:kube-scheduler 
Name:		system:kube-scheduler
Labels:		kubernetes.io/bootstrapping=rbac-defaults
Annotations:	rbac.authorization.kubernetes.io/autoupdate=true
PolicyRule:
  Resources			Non-Resource URLs	Resource Names		Verbs
  ---------			-----------------	--------------		-----
  bindings			[]			[]			[create]
  endpoints			[]			[]			[create]
  endpoints			[]			[kube-scheduler]	[delete]
  endpoints			[]			[kube-scheduler]	[get]
  endpoints			[]			[kube-scheduler]	[patch]
  endpoints			[]			[kube-scheduler]	[update]
  events			[]			[]			[create patch update]
  nodes				[]			[]			[get list watch]
  persistentvolumeclaims	[]			[]			[get list watch]
  persistentvolumes		[]			[]			[get list watch]
  pods				[]			[]			[get list watch]
  pods/binding			[]			[]			[create]
  pods/status			[]			[]			[update]
  replicasets.extensions	[]			[]			[get list watch]
  replicationcontrollers	[]			[]			[get list watch]
  services			[]			[]			[get list watch]
  statefulsets.apps		[]			[]			[get list watch]

```
**Which issue this PR fixes**: 

**Special notes for your reviewer**:

**Release note**:

```release-note
NONE
```

pkg/apis/rbac/helpers.go

@@ -124,6 +124,38 @@ func SubjectsStrings(subjects []Subject) ([]string, []string, []string, []string
 	return users, groups, sas, others
 }
 
+func (r PolicyRule) String() string {
+	return "PolicyRule" + r.CompactString()
+}
+
+// CompactString exposes a compact string representation for use in escalation error messages
+func (r PolicyRule) CompactString() string {
+	formatStringParts := []string{}
+	formatArgs := []interface{}{}
+	if len(r.Resources) > 0 {
+		formatStringParts = append(formatStringParts, "Resources:%q")
+		formatArgs = append(formatArgs, r.Resources)
+	}
+	if len(r.NonResourceURLs) > 0 {
+		formatStringParts = append(formatStringParts, "NonResourceURLs:%q")
+		formatArgs = append(formatArgs, r.NonResourceURLs)
+	}
+	if len(r.ResourceNames) > 0 {
+		formatStringParts = append(formatStringParts, "ResourceNames:%q")
+		formatArgs = append(formatArgs, r.ResourceNames)
+	}
+	if len(r.APIGroups) > 0 {
+		formatStringParts = append(formatStringParts, "APIGroups:%q")
+		formatArgs = append(formatArgs, r.APIGroups)
+	}
+	if len(r.Verbs) > 0 {
+		formatStringParts = append(formatStringParts, "Verbs:%q")
+		formatArgs = append(formatArgs, r.Verbs)
+	}
+	formatString := "{" + strings.Join(formatStringParts, ", ") + "}"
+	return fmt.Sprintf(formatString, formatArgs...)
+}
+
 // +k8s:deepcopy-gen=false
 // PolicyRuleBuilder let's us attach methods.  A no-no for API types.
 // We use it to construct rules in code.  It's more compact than trying to write them
@@ -341,3 +373,11 @@ func (r *RoleBindingBuilder) Binding() (RoleBinding, error) {
 
 	return r.RoleBinding, nil
 }
+
+type SortableRuleSlice []PolicyRule
+
+func (s SortableRuleSlice) Len() int      { return len(s) }
+func (s SortableRuleSlice) Swap(i, j int) { s[i], s[j] = s[j], s[i] }
+func (s SortableRuleSlice) Less(i, j int) bool {
+	return strings.Compare(s[i].String(), s[j].String()) < 0
+}