title: Can not get data with etcdctl but Can do with curl
body: <p>I can get data from etcd with curl, like follow:</p>
  
  <pre><code>core ~ $ curl http://10.12.1.105:2379/v2/keys/zk/codis/db_test
         {"action":"get","node":   {"key":"/zk/codis/db_test","dir":true,"expiration":"2016-09-   18T06:35:35.892545267Z","ttl":31535019,"nodes":    [{"key":"/zk/codis/db_test/ActionResponse","dir":true,"expiration":"2016-09-   18T06:40:45.162912721Z","ttl":31535328,"modifiedIndex":10,"createdIndex":10},
  {"key":"/zk/codis/db_test/LOCK","dir":true,"expiration":"2016-09-18T06:48:07.460467703Z","ttl":31535770,"modifiedIndex":5130,"createdIndex":5130},
  {"key":"/zk/codis/db_test/servers","dir":true,"modifiedIndex":5132,"createdIndex":5132},
  {"key":"/zk/codis/db_test/dashboard","value":"{\"addr\": \"10.12.1.101:18087\", \"pid\": 9}","expiration":"2016-09-18T06:35:35.90202187Z","ttl":31535019,"modifiedIndex":6,"createdIndex":6},{"key":"/zk/codis/db_test/migrate_tasks","dir":true,"expiration":"2016-09-18T06:35:35.909309855Z","ttl":31535019,"modifiedIndex":7,"createdIndex":7},
  {"key":"/zk/codis/db_test/slots","dir":true,"modifiedIndex":8,"createdIndex":8},
  {"key":"/zk/codis/db_test/actions","dir":true,"expiration":"2016-09-18T06:40:45.15502607Z","ttl":31535328,"modifiedIndex":9,"createdIndex":9}],"modifiedIndex":5,"createdIndex":5}}
  </code></pre>
  
  <p>But I Can not get data from etcd2 with etcdctl :</p>
  
  <pre><code>core@hack-day-master ~ $ etcdctl -C 10.12.1.105:2379 ls
  /coreos.com
  </code></pre>
  
  <p>Who can help me?</p>