restore old cached client behavior

pkg/kubectl/cmd/testing/fake.go

@@ -420,7 +420,7 @@ func (f *TestFactory) DiscoveryClient() (discovery.CachedDiscoveryInterface, err
 	fakeClient := f.Client.(*fake.RESTClient)
 
 	cacheDir := filepath.Join("", ".kube", "cache", "discovery")
-	cachedClient, err := discovery.NewCachedDiscoveryClientForConfig(f.ClientConfigVal, cacheDir, time.Duration(10*time.Minute))
+	cachedClient, err := discovery.NewCachedDiscoveryClientForConfig(f.ClientConfigVal, cacheDir, "", time.Duration(10*time.Minute))
 	if err != nil {
 		return nil, err
 	}

pkg/kubectl/cmd/util/config_flags.go

@@ -52,6 +52,8 @@ const (
 	flagHTTPCacheDir     = "cache-dir"
 )
 
+var defaultCacheDir = filepath.Join(homedir.HomeDir(), ".kube", "http-cache")
+
 // TODO(juanvallejo): move to pkg/kubectl/genericclioptions once
 // the dependency on cmdutil is broken here.
 // ConfigFlags composes the set of values necessary
@@ -176,8 +178,15 @@ func (f *ConfigFlags) ToDiscoveryClient() (discovery.CachedDiscoveryInterface, e
 	// double it just so we don't end up here again for a while.  This config is only used for discovery.
 	config.Burst = 100
 
-	cacheDir := computeDiscoverCacheDir(filepath.Join(homedir.HomeDir(), ".kube", "cache", "discovery"), config.Host)
-	return discovery.NewCachedDiscoveryClientForConfig(config, cacheDir, time.Duration(10*time.Minute))
+	// retrieve a user-provided value for the "cache-dir"
+	// defaulting to ~/.kube/http-cache if no user-value is given.
+	httpCacheDir := defaultCacheDir
+	if f.CacheDir != nil {
+		httpCacheDir = *f.CacheDir
+	}
+
+	discoveryCacheDir := computeDiscoverCacheDir(filepath.Join(homedir.HomeDir(), ".kube", "cache", "discovery"), config.Host)
+	return discovery.NewCachedDiscoveryClientForConfig(config, discoveryCacheDir, httpCacheDir, time.Duration(10*time.Minute))
 }
 
 // RESTMapper returns a mapper.
@@ -271,6 +280,7 @@ func NewConfigFlags() *ConfigFlags {
 		Timeout:    stringptr("0"),
 		KubeConfig: stringptr(""),
 
+		CacheDir:         stringptr(defaultCacheDir),
 		ClusterName:      stringptr(""),
 		AuthInfoName:     stringptr(""),
 		Context:          stringptr(""),

staging/src/k8s.io/client-go/discovery/cached_discovery.go

@@ -239,10 +239,18 @@ func (d *CachedDiscoveryClient) Invalidate() {
 }
 
 // NewCachedDiscoveryClientForConfig creates a new DiscoveryClient for the given config, and wraps
-// the created client in a CachedDiscoveryClient. The provided configuration is upddated with a
+// the created client in a CachedDiscoveryClient. The provided configuration is updated with a
 // custom transport that understands cache responses.
-func NewCachedDiscoveryClientForConfig(config *restclient.Config, cacheDirectory string, ttl time.Duration) (*CachedDiscoveryClient, error) {
-	if len(cacheDirectory) > 0 {
+// We receive two distinct cache directories for now, in order to preserve old behavior
+// which makes use of the --cache-dir flag value for storing cache data from the CacheRoundTripper,
+// and makes use of the hardcoded destination (~/.kube/cache/discovery/...) for storing
+// CachedDiscoveryClient cache data. If httpCacheDir is empty, the restconfig's transport will not
+// be updated with a roundtripper that understands cache responses.
+// If discoveryCacheDir is empty, cached server resource data will be looked up in the current directory.
+// TODO(juanvallejo): the value of "--cache-dir" should be honored. Consolidate discoveryCacheDir with httpCacheDir
+// so that server resources and http-cache data are stored in the same location, provided via config flags.
+func NewCachedDiscoveryClientForConfig(config *restclient.Config, discoveryCacheDir, httpCacheDir string, ttl time.Duration) (*CachedDiscoveryClient, error) {
+	if len(httpCacheDir) > 0 {
 		// update the given restconfig with a custom roundtripper that
 		// understands how to handle cache responses.
 		wt := config.WrapTransport
@@ -250,7 +258,7 @@ func NewCachedDiscoveryClientForConfig(config *restclient.Config, cacheDirectory
 			if wt != nil {
 				rt = wt(rt)
 			}
-			return newCacheRoundTripper(cacheDirectory, rt)
+			return newCacheRoundTripper(httpCacheDir, rt)
 		}
 	}
 
@@ -259,7 +267,7 @@ func NewCachedDiscoveryClientForConfig(config *restclient.Config, cacheDirectory
 		return nil, err
 	}
 
-	return newCachedDiscoveryClient(discoveryClient, cacheDirectory, ttl), nil
+	return newCachedDiscoveryClient(discoveryClient, discoveryCacheDir, ttl), nil
 }
 
 // NewCachedDiscoveryClient creates a new DiscoveryClient.  cacheDirectory is the directory where discovery docs are held.  It must be unique per host:port combination to work well.

staging/src/k8s.io/metrics/Godeps/Godeps.json

@@ -82,6 +82,10 @@
 			"ImportPath": "github.com/modern-go/reflect2",
 			"Rev": "05fbef0ca5da472bbf96c9322b84a53edc03c9fd"
 		},
+		{
+			"ImportPath": "github.com/peterbourgon/diskv",
+			"Rev": "5f041e8faa004a95c88a202771f4cc3e991971e6"
+		},
 		{
 			"ImportPath": "golang.org/x/crypto/ssh/terminal",
 			"Rev": "49796115aa4b964c318aad4f3084fdb41e9aa067"

test/integration/apiserver/print_test.go

@@ -165,7 +165,7 @@ func TestServerSidePrint(t *testing.T) {
 		os.Remove(cacheDir)
 	}()
 
-	cachedClient, err := discovery.NewCachedDiscoveryClientForConfig(restConfig, cacheDir, time.Duration(10*time.Minute))
+	cachedClient, err := discovery.NewCachedDiscoveryClientForConfig(restConfig, cacheDir, "", time.Duration(10*time.Minute))
 	if err != nil {
 		t.Errorf("unexpected error: %v", err)
 	}