fixes moby#23983

mavenugo · Tibor Vass · commit b74b71ecb31e · 2016-07-08T15:33:29.000-07:00
Signed-off-by: Madhu Venugopal <madhu@docker.com> (cherry picked from commit 6a4b21b) Signed-off-by: Tibor Vass <tibor@docker.com>
diff --git a/api/server/router/network/network_routes.go b/api/server/router/network/network_routes.go
@@ -81,6 +81,10 @@ func (n *networkRouter) postNetworkCreate(ctx context.Context, w http.ResponseWr
 		return err
 	}
 
+	if _, err := n.clusterProvider.GetNetwork(create.Name); err == nil {
+		return libnetwork.NetworkNameError(create.Name)
+	}
+
 	nw, err := n.backend.CreateNetwork(create)
 	if err != nil {
 		if _, ok := err.(libnetwork.ManagerRedirectError); !ok {
