Apache Module mod_proxy_wstunnel

Summary

This module requires the service of mod_proxy. It provides support for the tunnelling of web socket connections to a backend websockets server. The connection is automatically upgraded to a websocket connection:

Upgrade: WebSocket
Connection: Upgrade

Proxying requests to a websockets server like echo.websocket.org can be done using the ProxyPass directive:

ProxyPass "/ws2/"  "ws://echo.websocket.org/"
ProxyPass "/wss2/" "wss://echo.websocket.org/"

Proxying both HTTP and websockets at the same time, with a specific set of URL's being websocket-only, can be done by specifying the websockets ProxyPass directive before the HTTP directive:

ProxyPassMatch ^/(myApp/ws)$  ws://backend.example.com:9080/$1
ProxyPass / http://backend.example.com:9080/

Proxying both HTTP and websockets at the same time, where the websockets URL's are not websocket-only or not known in advance can be done by using the RewriteRule directive to configure the websockets proxying:

ProxyPass / http://example.com:9080/
RewriteEngine on
RewriteCond %{HTTP:Upgrade} websocket [NC]
RewriteCond %{HTTP:Connection} upgrade [NC]
RewriteRule ^/?(.*) "ws://example.com:9080/$1" [P,L]

Load balancing for multiple backends can be achieved using mod_proxy_balancer.

In fact the module can be used to upgrade to other protocols, you can set the upgrade parameter in the ProxyPass directive to allow the module to accept other protocol. NONE means you bypass the check for the header but still upgrade to WebSocket. ANY means that Upgrade will read in the request headers and use in the response Upgrade

Directives

• ProxyWebsocketFallbackToProxyHttp

Bugfix checklist

• httpd changelog
• Known issues
• Report a bug

See also

• mod_proxy
• Comments