istioctl: Fix path for Mixer Config server (#692)

Manager and mixer API server paths are not consistent. Manager path is
prefixed with Istio resource version (i.e. v1alpha1) and mixer path is
not. Short term workaround is to special case this behavior. Long term
solution is to unify API scheme and server implementations.

See istio/api#94 for long term tracking.

Author: ayj

platform/kube/client.go

@@ -411,8 +411,22 @@ func (cl *Client) GetTLSSecret(uri string) (*model.TLSSecret, error) {
 // the a Kubernetes service.
 // (see https://kubernetes.io/docs/concepts/cluster-administration/access-cluster/#discovering-builtin-services)
 func (cl *Client) Request(namespace, service, method, path string, inBody []byte) (int, []byte, error) {
-	absPath := fmt.Sprintf("api/v1/namespaces/%s/services/%s/proxy/%s/%s",
-		namespace, service, IstioResourceVersion, path)
+	// Kubernetes apiserver proxy prefix for the specified namespace and service.
+	absPath := fmt.Sprintf("api/v1/namespaces/%s/services/%s/proxy", namespace, service)
+
+	// TODO(https://github.com/istio/api/issues/94) - Manager and
+	// mixer API server paths are not consistent. Manager path is
+	// prefixed with Istio resource version (i.e. v1alpha1) and mixer
+	// path is not. Short term workaround is to special case this
+	// behavior. Long term solution is to unify API scheme and server
+	// implementations.
+	if strings.HasPrefix(path, "config") {
+		absPath += "/" + IstioResourceVersion // manager api server patha
+	}
+
+	// API server resource path.
+	absPath += "/" + path
+
 	var status int
 	outBody, err := cl.dyn.Verb(method).
 		AbsPath(absPath).