NodeJs Error during WebSocket handshake - node.js

Question

I am able to establish a websocket connection, from a clienJS to NodeJs. But fails to connect websocket, when the request pass through apache httpd.
Using Httpd2.4.7, I am getting the below error. Please let me know what needs to be corrected.
WebSocket connection to 'ws://172.27.38.86/socket.io/1/websocket/_uW8Sv7lgQfrZncTSzKu' failed: Error during WebSocket handshake: Unexpected response code: 502
Thanks & Regards
Jawahar

Answer 1

Apache SUCKS at handling websockets through proxies. I recommend either getting rid of the Apache layer, or modifying your socket.io settings to use XHR polling.

Answer 2

After 2.4.5, apache included a module called proxy_wstunnel on their trunk, not available yet on current ubuntu production versions of apache (2.4.7). It was somehow painful, but following roughly the steps listed on this blog-post I managed to install the module and use it successfully.
dpkg -s apache2 //this gives you the version of apache in my case "2.4.7-1ubuntu4.1"
//then you checkout that version of apache
svn co http://svn.apache.org/viewvc/httpd/httpd/tags/2.4.7/
//you get into the directory just checked out
cd 2.4.7
//in there you checkout the Apache Portable Runtime Project and utils
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
//you compile with the corresponding modules flags
./buildconf
./configure --enable-proxy=shared --enable-proxy_wstunnel=shared
make
//You copy the modules (mod_proxy and mod_proxy_wstunnel) to your apache working copy
//It could be advisable to backup the old mods first
sudo cp modules/proxy/.libs/mod_proxy{_wstunnel,}.so /usr/lib/apache2/modules/
sudo chmod 644 /usr/lib/apache2/modules/mod_proxy{_wstunnel,}.so
sudo 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
//you then enable your module and restart your apache... so now the module is ready to use
sudo a2enmod proxy_wstunnel
sudo service apache2 restart
and after all that, researching a little bit I found this page I configured my apache vhost file accordingly like this
<VirtualHost *:80>
ServerAdmin yourmail#mail.com
ServerName yoursubdomain.yourdomain.info
Redirect permanent / https://yoursubdomain.yourdomain.info
</VirtualHost>
<VirtualHost *:443>
ServerAdmin yourmail#mail.com
ServerName yoursubdomain.yourdomain.info
ProxyRequests off
<Proxy *>
Order deny,allow
Allow from all
</Proxy>
ProxyPreserveHost On
//these next two lines are to enable the wstunnel
ProxyPass /socket.io/1/websocket ws://localhost:9091/socket.io/1/websocket
ProxyPassReverse /socket.io/1/websocket ws://localhost:9091/socket.io/1/websocket
//this line is to retrieve the socket.io.js to use
ProxyPass /socket.io/ http://localhost:9091/socket.io/
SSLEngine on
SSLCertificateFile /etc/ssl/certs/yourcert.crt
SSLCertificateKeyFile /etc/ssl/private/yourcert.key
SSLCertificateChainFile /etc/ssl/certs/your_bundle.crt
//your logs
CustomLog /var/log/apache2/yoursubdomain.yourdomain.info.log combined
ErrorLog /var/log/apache2/yoursubdomain.yourdomain.info.error.log
</VirtualHost>
And TaDaaa... I have a working node websocket responding on port 9091 through an apache proxy that gets everything trough the 443 standard ssl port.
I suppose ubuntu will soon include this module on their production version, but meanwhile this is the way to go

Answer 3

I had to setup ws tunnel in CentOs, where apache 2.2.15 was installed by default.
I have tried patching proxy_wstunnel module with apache 2.2.15. But no help. Finally I have decided to remove apache 2.2.15 and install apache 2.4 by following the official documentation from http://httpd.apache.org/docs/2.4/install.html
After installation (I have installed in the default location /usr/local/apache2/), I did the following to get tunneling work
uncomment the following lines from /usr/local/apache2/conf/httpd.conf
LoadModule proxy_module modules/mod_proxy.so
LoadModule proxy_wstunnel_module modules/mod_proxy_wstunnel.so
Add a virtual host for tunneling websocket requests
<VirtualHost *:80>
ServerName subdomain.mydomain.com
ProxyPass / ws://localhost:8081/
ProxyPassReverse / ws://localhost:8081/
</VirtualHost>
from my frontend the websocket is connected via ws://subdomain.mydomain.com:80
restart apache using
sudo /usr/local/apache2/bin/apachectl -k restart