Merge pull request #41651 from shashidharatd/kubefed-3

Automatic merge from submit-queue (batch tested with PRs 41401, 41195, 41664, 41521, 41651)

[Federation][kubefed] Add label selector for etcd pvc

Currently, etcd pvc created for federation etcd does not have a label selector. without a label selector etcd pvc will bind to any pv created statically, this may be problematic in real environments comprising multiple pv's.

Also, verified that we can create a pv statically with labels as below
 ```
  labels:
    "app": "federated-cluster"
    "module": "federation-apiserver"
```
and federation etcd pvc will be bound to the pv matching label.
This is one of the side task, that we discussed in [here](https://github.com/kubernetes/kubernetes/issues/41127#issuecomment-278881319)

cc @madhusudancs @kubernetes/sig-federation-bugs

federation/pkg/kubefed/init/init.go

@@ -549,6 +549,7 @@ func createPVC(clientset *client.Clientset, namespace, svcName, etcdPVCapacity s
 					api.ResourceStorage: capacity,
 				},
 			},
+			Selector: &metav1.LabelSelector{MatchLabels: apiserverSvcSelector},
 		},
 	}
 

federation/pkg/kubefed/init/init_test.go

@@ -672,6 +672,7 @@ func fakeInitHostFactory(apiserverServiceType v1.ServiceType, federationName, na
 					v1.ResourceStorage: capacity,
 				},
 			},
+			Selector: &metav1.LabelSelector{MatchLabels: apiserverSvcSelector},
 		},
 	}