Apache 2.2 Websocket Proxying on Ubuntu with mod_proxy_wstunnel

Until recently, I was running a Node.js web application using Websockets with socket.io alongside an Apache web server. I wanted Apache to run on port 80 and serve both sites using name-based virtual hosting. However, Apache httpd mod_proxy couldn’t proxy Websockets correctly.

I discovered that there is a new mod_proxy_wstunnel module in the Apache httpd source trunk in an article describing how to backport mod_proxy_wstunnel to Apache 2.4 or 2.2. I figured out the specific steps for doing this on Ubuntu (tested on 11.10 with Apache httpd 2.2.20). I wanted to add them as a comment, but they were disabled on that blog.

Here are the steps, see the original blog post of the patch author for more information:

# 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 # EDIT: Some commenters noted that buildconf should be run before the configure
./configure --enable-proxy=shared --enable-proxy_wstunnel=shared

# 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

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