title: confluentinc/cp-zookeeper Docker Image and ZooKeeper's four letter word whitelist
body: <p>ZooKeeper defines the Java property <a href="https://zookeeper.apache.org/doc/current/zookeeperAdmin.html#sc_clusterOptions" rel="nofollow noreferrer">4lw.commands.whitelist</a> to enable certain four letter word commands. Using <a href="https://hub.docker.com/r/confluentinc/cp-zookeeper" rel="nofollow noreferrer">Confluent's</a> ZooKeeper Docker image, how can we specify values for this?</p>
  
  <p>In "docker run", I've tried:</p>
  
  <pre><code>-e ZOOKEEPER_4LW_COMMANDS_WHITELIST=stat
  -e ZOO_4LW_COMMANDS_WHITELIST=stat
  </code></pre>
  
  <p>But looking at the log, these have no effect. Only srvr is enabled.</p>