From 7c58f94edcced7169784aa4fd1e6e63dc5ed3029 Mon Sep 17 00:00:00 2001
From: Muhammed Uluyol <uluyol@google.com>
Date: Tue, 18 Aug 2015 14:25:38 -0700
Subject: [PATCH] Create an experimental client cache.

Previously, we would initialize the experimental client at factory creation
time. This is problematic because the clientConfig loader has values populated
from the command-line flag parsing, and these are not populated until after
Factory creation. Introduce an ExperimentalClientCache to create (and reuse)
ExperimentalClients.
---
 pkg/kubectl/cmd/util/clientcache.go | 25 +++++++++++++++++++++++++
 pkg/kubectl/cmd/util/factory.go     | 18 ++++++------------
 2 files changed, 31 insertions(+), 12 deletions(-)

diff --git a/pkg/kubectl/cmd/util/clientcache.go b/pkg/kubectl/cmd/util/clientcache.go
index c43fcca264e..49253b7e3da 100644
--- a/pkg/kubectl/cmd/util/clientcache.go
+++ b/pkg/kubectl/cmd/util/clientcache.go
@@ -89,3 +89,28 @@ func (c *ClientCache) ClientForVersion(version string) (*client.Client, error) {
 	c.clients[config.Version] = client
 	return client, nil
 }
+
+type ExperimentalClientCache struct {
+	loader clientcmd.ClientConfig
+	client *client.ExperimentalClient
+	err    error
+	init   bool
+}
+
+func NewExperimentalClientCache(loader clientcmd.ClientConfig) *ExperimentalClientCache {
+	return &ExperimentalClientCache{loader: loader}
+}
+
+func (cc *ExperimentalClientCache) Client() (*client.ExperimentalClient, error) {
+	if cc.init {
+		return cc.client, cc.err
+	}
+	cfg, err := cc.loader.ClientConfig()
+	if err != nil {
+		cc.err = err
+	} else {
+		cc.client, cc.err = client.NewExperimental(cfg)
+	}
+	cc.init = true
+	return cc.client, cc.err
+}
diff --git a/pkg/kubectl/cmd/util/factory.go b/pkg/kubectl/cmd/util/factory.go
index fed40ad8273..b429ea582cc 100644
--- a/pkg/kubectl/cmd/util/factory.go
+++ b/pkg/kubectl/cmd/util/factory.go
@@ -110,14 +110,7 @@ func NewFactory(optionalClientConfig clientcmd.ClientConfig) *Factory {
 	}
 
 	clients := NewClientCache(clientConfig)
-
-	// Initialize the experimental client (if possible). Failing here is non-fatal, errors
-	// will be returned when an experimental client is explicitly requested.
-	var experimentalClient *client.ExperimentalClient
-	cfg, experimentalClientErr := clientConfig.ClientConfig()
-	if experimentalClientErr == nil {
-		experimentalClient, experimentalClientErr = client.NewExperimental(cfg)
-	}
+	expClients := NewExperimentalClientCache(clientConfig)
 
 	noClientErr := errors.New("could not get client")
 	getBothClients := func(group string, version string) (client *client.Client, expClient *client.ExperimentalClient, err error) {
@@ -126,7 +119,7 @@ func NewFactory(optionalClientConfig clientcmd.ClientConfig) *Factory {
 		case "api":
 			client, err = clients.ClientForVersion(version)
 		case "experimental":
-			expClient, err = experimentalClient, experimentalClientErr
+			expClient, err = expClients.Client()
 		}
 		return
 	}
@@ -146,7 +139,7 @@ func NewFactory(optionalClientConfig clientcmd.ClientConfig) *Factory {
 			return clients.ClientForVersion("")
 		},
 		ExperimentalClient: func() (*client.ExperimentalClient, error) {
-			return experimentalClient, experimentalClientErr
+			return expClients.Client()
 		},
 		ClientConfig: func() (*client.Config, error) {
 			return clients.ClientConfigForVersion("")
@@ -164,7 +157,7 @@ func NewFactory(optionalClientConfig clientcmd.ClientConfig) *Factory {
 				}
 				return client.RESTClient, nil
 			case "experimental":
-				client, err := experimentalClient, experimentalClientErr
+				client, err := expClients.Client()
 				if err != nil {
 					return nil, err
 				}
@@ -260,7 +253,8 @@ func NewFactory(optionalClientConfig clientcmd.ClientConfig) *Factory {
 				if err != nil {
 					return nil, err
 				}
-				return &clientSwaggerSchema{client, experimentalClient, api.Scheme}, nil
+				expClient, _ := expClients.Client()
+				return &clientSwaggerSchema{client, expClient, api.Scheme}, nil
 			}
 			return validation.NullSchema{}, nil
 		},