Enable WebSockets

How to enable WebSockets, when configuring the Knox Gateway. Enabling WebSockets for Knox allows you to proxy applications that use WebSocket connections (e.g., Zeppelin.)

WebSocket is a communication protocol that allows full duplex communication over single TCP connection. Knox provides out-of-the-box support for WebSocket protocol, but currently, only text-based messages are supported.

By default, WebSocket functionality is disabled. WebSocket functionality must be enabled for Zeppelin UI (<role>ZEPPELINUI</role>) service definition to work.

In /conf/gateway-site.xml, change gateway.websocket.feature.enabled to true:

<property>
      <name>gateway.websocket.feature.enabled</name>
      <value>true</value>
      <description>Enable/Disable websocket feature.</description>
  </property>

In /conf/{topology}.xml, change the topology rule:

<service>
      <role>WEBSOCKET</role>
      <url>ws://myhost:9999/ws</url>
  </service>

Restart the gateway:

cd $gateway bin/gateway.sh stop bin/gateway.sh start