Configuring Apache2 to proxy WebSocket?

There is now a module in the Apache trunk called mod_proxy_wstunnel which allows mod_proxy (ProxyPass/ProxyPassReverse) to pass through WebSocket traffic. Someone wrote a blog post about back-porting mod_proxy_wstunnel to Apache 2.4/2.2 and provided a patch to do so.

I figured out concrete instructions to set up mod_proxy_wstunnel on Ubuntu (tested with Ubuntu Server 11.10 and Apache 2.2.20) and posted them on my blog. I have copied them below:

# Check apache version (should be 2.2.20 as of writing, if not adjust the next step)
dpkg -s apache2

# Checkout apache source
svn checkout http://svn.apache.org/repos/asf/httpd/httpd/tags/2.2.20/ httpd-2.2.20

# Get patch and apply it
wget http://cafarelli.fr/gentoo/apache-2.2.24-wstunnel.patch
cd httpd-2.2.20
patch -p1 < ../apache-2.2.24-wstunnel.patch

# Build Apache 
svn co http://svn.apache.org/repos/asf/apr/apr/branches/1.4.x srclib/apr
svn co http://svn.apache.org/repos/asf/apr/apr-util/branches/1.3.x srclib/apr-util
./buildconf
./configure --enable-proxy=shared --enable-proxy_wstunnel=shared
make

# Copy the module and recompiled mod_proxy (for new symbols) to the ubuntu apache installation and update the permissions to match the other modules
sudo cp modules/proxy/.libs/mod_proxy{_wstunnel,}.so /usr/lib/apache2/modules/
sudo chmod 644 /usr/lib/apache2/modules/mod_proxy{_wstunnel,}.so
echo -e "# Depends: proxy\nLoadModule proxy_wstunnel_module /usr/lib/apache2/modules/mod_proxy_wstunnel.so" | sudo tee -a /etc/apache2/mods-available/proxy_wstunnel.load

# Enable the module (also make any configuration changes you need)
sudo a2enmod proxy_wstunnel
sudo service apache2 restart

There is nothing to indicate Apache httpd will support them anytime soon.

If you must run websockets through apache, try mod_pywebsocket. I have tried it, and it does work.

Here are a few alternatives I prefer:

  • serve websockets on a different port, avoiding the Apache httpd altogether.
  • try haproxy as suggested here.
  • switch to Nginx, use tcp proxy module, read article.

Looks like with a combination of the disconnect plugin and some extra code this is now possible:

http://blog.alex.org.uk/2012/02/16/using-apache-websocket-to-proxy-tcp-connection/


Please take a look at http://github.com/disconnect/apache-websocket

The apache-websocket module is an Apache 2.x server module that may be used to process requests using the WebSocket protocol by an Apache 2.x server.