WebSockets and Apache proxy : how to configure mod_proxy_wstunnel?

Question

I have :

1. Apache 2.4 on port 80 of my server, with mod_proxy and mod_proxy_wstunnel enabled

2. Node.js + socket.io on port 3001 of the same server

Accessing example.com (with port 80) redirects to 2. thanks to this method with the following Apache configuration:

<VirtualHost *:80>
    ServerName example.com
    ProxyPass / http://localhost:3001/
    ProxyPassReverse / http://localhost:3001/
    ProxyPass / ws://localhost:3001/
    ProxyPassReverse / ws://localhost:3001/
</VirtualHost>

It works for everything, except the websocket part : ws://... are not transmitted like it should by the proxy.

When I access the page on example.com, I have:

Impossible to connect ws://example.com/socket.io/?EIO=3&transport=websocket&sid=n30rqg9AEqZIk5c9AABN.

Question: How to make Apache proxy the WebSockets as well?

Answer 1

I finally managed to do it, thanks to this topic. TODO:

1) Have Apache 2.4 installed (doesn't work with 2.2), and do:

a2enmod proxy
a2enmod proxy_http
a2enmod proxy_wstunnel

2) Have nodejs running on port 3001

3) Do this in the Apache config

<VirtualHost *:80>
  ServerName example.com

  RewriteEngine On
  RewriteCond %{REQUEST_URI}  ^/socket.io            [NC]
  RewriteCond %{QUERY_STRING} transport=websocket    [NC]
  RewriteRule /(.*)           ws://localhost:3001/$1 [P,L]

  ProxyPass / http://localhost:3001/
  ProxyPassReverse / http://localhost:3001/
</VirtualHost>

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Note: if you have more than one service on the same server that uses websockets, you might want to do this to separate them.