title: Kafka user authentication using SASL_PLAINTEXT
body: <p>I'm trying to implement security in Kafka to authenticate the clients using username and password. The jaas config file is configured properly. I'm starting zookeeper first and then starting just one kafka node. However kafka fails to start with the below error:</p>
  
  <pre><code>[2017-08-07 13:07:08,029] INFO Registered broker 0 at path /brokers/ids/0 with addresses: EndPoint(localhost,9092,ListenerName(SASL_PLAINTEXT),SASL_PLAINTEXT) (kafka.utils.ZkUtils) 
  [2017-08-07 13:07:08,035] INFO Kafka version : 0.11.0.0 (org.apache.kafka.common.utils.AppInfoParser) [2017-08-07 13:07:08,036] INFO Kafka commitId : cb8625948210849f (org.apache.kafka.common.utils.AppInfoParser) 
  [2017-08-07 13:07:08,037] INFO [Kafka Server 0], started (kafka.server.KafkaServer)    
  [2017-08-07 13:07:08,447] WARN Connection to node 0 terminated during authentication. This may indicate that authentication failed due to invalid credentials. (org.apache.kafka.clients.NetworkClient) 
  [2017-08-07 13:07:08,554] WARN Connection to node 0 terminated during authentication. This may indicate that authentication failed due to invalid credentials. (org.apache.kafka.clients.NetworkClient) 
  [2017-08-07 13:07:08,662] WARN Connection to node 0 terminated during authentication. This may indicate that authentication failed due to invalid credentials. (org.apache.kafka.clients.NetworkClient)
  </code></pre>