integration: test namespacing on proxy layer

Hardcode a namespace over the testing grpcproxy.

integration/cluster_proxy.go

@@ -20,6 +20,7 @@ import (
 	"sync"
 
 	"github.com/coreos/etcd/clientv3"
+	"github.com/coreos/etcd/clientv3/namespace"
 	pb "github.com/coreos/etcd/etcdserver/etcdserverpb"
 	"github.com/coreos/etcd/proxy/grpcproxy"
 	"github.com/coreos/etcd/proxy/grpcproxy/adapter"
@@ -30,6 +31,8 @@ var (
 	proxies map[*clientv3.Client]grpcClientProxy = make(map[*clientv3.Client]grpcClientProxy)
 )
 
+const proxyNamespace = "proxy-namespace"
+
 type grpcClientProxy struct {
 	grpc    grpcAPI
 	wdonec  <-chan struct{}
@@ -44,9 +47,16 @@ func toGRPC(c *clientv3.Client) grpcAPI {
 	if v, ok := proxies[c]; ok {
 		return v.grpc
 	}
+
+	// test namespacing proxy
+	c.KV = namespace.NewKV(c.KV, proxyNamespace)
+	c.Watcher = namespace.NewWatcher(c.Watcher, proxyNamespace)
+	c.Lease = namespace.NewLease(c.Lease, proxyNamespace)
+	// test coalescing/caching proxy
 	kvp, kvpch := grpcproxy.NewKvProxy(c)
 	wp, wpch := grpcproxy.NewWatchProxy(c)
 	lp, lpch := grpcproxy.NewLeaseProxy(c)
+
 	grpc := grpcAPI{
 		pb.NewClusterClient(c.ActiveConnection()),
 		adapter.KvServerToKvClient(kvp),