At Flexiant, we had a need for a general websocket to tcp proxy. A cute apache module to do extensible web-sockets programming has been developed by self.disconnect, and is available on github here. I’ve hacked around with this to produce a generic, apache licensed, websocket proxy. A websocket connection is made over HTTP or HTTPS to apache, this calls the websocket module, which in turn calls my module, which makes an outbound tcp connection.
Some features:
- It supports base64 and text format sockets. So it will thus process (for instance) VNC which works using base64 encoding.
- Configuration is supplied through normal apache directory based configuration (see details below).
- It’s extensible (currently by changing the code, rather than calling additional modules)
The configuration section looks like this, in this case set up to proxy VNC using a novnc client:
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<IfModule mod_websocket.c> <Location /vncproxy> SetHandler websocket–handler WebSocketHandler /usr/lib/apache2/modules/mod_websocket_tcp_proxy.so tcp_proxy_init WebSocketTcpProxyBase64 on WebSocketTcpProxyHost 192.168.199.199 WebSocketTcpProxyPort 5900 WebSocketTcpProxyProtocol base64 </Location> </IfModule> |
Note that the parameter you specify for Location must not be a file or directory that exists with your docroot, or you will just get 404 or similar. So, in the above example you must not have a file or directory at ${DOCROOT}/vncproxy.
I discovered that on a default apache install, you may also want to change the RequestReadTimeout, i.e.
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<IfModule reqtimeout_module> RequestReadTimeout body=300,minrate=1 </IfModule> |
I’m going to try and persuade self.disconnect to stick this in the examples directory for apache-websocket, but in the mean time the source is available here. Put it in the examples directory of apache-websocket, then compile, install and enable it with it with:
sudo apxs2 -c -i -a -I.. mod_websocket_tcp_proxy.c
[Update: see new blog post, git repo link here]
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