Merge pull request #60464 from roycaihw/loadconfig

Automatic merge from submit-queue (batch tested with PRs 63598, 63913, 63459, 63963, 60464). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Client-go raises error on duplicated name in kubeconfig

(for NamedCluster, NamedContext, NamedUser, NamedExtension)

**What this PR does / why we need it**:
Client should detect duplicated name when loading `name-value` based lists in kubeconfig: `users`, `clusters`, `contexts`. Currently if there are multiple value with same name, `client-python` will pick the first one, while `client-go` will pick the last.

**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
ref: kubernetes-client/python#445, kubernetes-client/python-base#47

**Special notes for your reviewer**:

**Release note**:

```release-note
kubectl and client-go now detects duplicated name for user, cluster and context when loading kubeconfig and reports error
```

/sig api-machinery

cc @brendandburns @mbohlool

Kubernetes-commit: 7909712ca574c536901bc7858dfbf72a3a6ee7dd

Author: k8s-publishing-bot

Godeps/Godeps.json

@@ -17,6 +17,7 @@ limitations under the License.
 package v1
 
 import (
+	"fmt"
 	"sort"
 
 	"k8s.io/apimachinery/pkg/conversion"
@@ -105,7 +106,11 @@ func addConversionFuncs(scheme *runtime.Scheme) error {
 				if err := s.Convert(&curr.Cluster, newCluster, 0); err != nil {
 					return err
 				}
-				(*out)[curr.Name] = newCluster
+				if (*out)[curr.Name] == nil {
+					(*out)[curr.Name] = newCluster
+				} else {
+					return fmt.Errorf("error converting *[]NamedCluster into *map[string]*api.Cluster: duplicate name \"%v\" in list: %v", curr.Name, *in)
+				}
 			}
 
 			return nil
@@ -136,7 +141,11 @@ func addConversionFuncs(scheme *runtime.Scheme) error {
 				if err := s.Convert(&curr.AuthInfo, newAuthInfo, 0); err != nil {
 					return err
 				}
-				(*out)[curr.Name] = newAuthInfo
+				if (*out)[curr.Name] == nil {
+					(*out)[curr.Name] = newAuthInfo
+				} else {
+					return fmt.Errorf("error converting *[]NamedAuthInfo into *map[string]*api.AuthInfo: duplicate name \"%v\" in list: %v", curr.Name, *in)
+				}
 			}
 
 			return nil
@@ -167,7 +176,11 @@ func addConversionFuncs(scheme *runtime.Scheme) error {
 				if err := s.Convert(&curr.Context, newContext, 0); err != nil {
 					return err
 				}
-				(*out)[curr.Name] = newContext
+				if (*out)[curr.Name] == nil {
+					(*out)[curr.Name] = newContext
+				} else {
+					return fmt.Errorf("error converting *[]NamedContext into *map[string]*api.Context: duplicate name \"%v\" in list: %v", curr.Name, *in)
+				}
 			}
 
 			return nil
@@ -198,7 +211,11 @@ func addConversionFuncs(scheme *runtime.Scheme) error {
 				if err := s.Convert(&curr.Extension, &newExtension, 0); err != nil {
 					return err
 				}
-				(*out)[curr.Name] = newExtension
+				if (*out)[curr.Name] == nil {
+					(*out)[curr.Name] = newExtension
+				} else {
+					return fmt.Errorf("error converting *[]NamedExtension into *map[string]runtime.Object: duplicate name \"%v\" in list: %v", curr.Name, *in)
+				}
 			}
 
 			return nil