Configure Reverse Proxy In cPanel

Setting up a reverse proxy or a regular CentOS server is quite straight forward, however when you have cPanel included in the equation, you need to be aware of a few things. That is why I've decided to write this short post here.

Here is what you need to do in order to get the reverse proxy working on a cPanel server:

Prerequisites

1. cPanel Server
2. Apache Modules
   1. mod_proxy -- Required
   2. mod_proxy_http -- Required
   3. mod_proxy_connect -- Required
   4. mod_proxy_wstunnel -- Optional. enable if you want to use WebSockets

Lets Get Started

Setup Apache Modules

Login to WHM and navigate To Home » Software » EasyApache 4

Click Customize On Currently Installed Packages

Once it loaded click Apache Modules In the Left-side Menu

Select All REQUIRED Proxy Modules That Mentioned Above

Once you have selected the modules click Review in the left menu.

And click Provision To install & Setup the apache modules.

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Creating A Reverse Proxy

Create a new file if not already exists in the below locations

STD -- Runs Without SSL

/usr/local/apache/conf/userdata/ssl/2_4/{user}/yourdomain.com/proxy_pass.conf

SSL -- Runs With SSL

/usr/local/apache/conf/userdata/std/2_4/{user}/yourdomain.com/proxy_pass.conf

(change '{user}' with the actual cPanel username')

Enable custom VHost file by running the below cmd

/scripts/ensure_vhost_includes --user={user}

After that you can then add the custom rules at the custom Vhost files which we created before.

Add below config to those VHosts file. which will forword all the requests for a domain to the given IP and also allows cPanel to handle SSL if it uses WEB ROOT to fetch SSL

###### DO NOT REMOVE BELOW LINE. IT USED TO AUTO RENEW SSL VIA CPANEL ######
ProxyPass "/.well-known"  !
###### DO NOT REMOVE ABOVE LINE. IT USED TO AUTO RENEW SSL VIA CPANEL ######

ProxyPass "/"  "http://10.0.3.2:80/"
ProxyPassReverse "/"  "http://10.0.3.2:80/"

Next step is to make sure that the written config is valid. run the below cmd

service httpd configtest

If you get 'Syntax OK' then run the below cmds to rebuild apache config & restart the Apache service

/scripts/rebuildhttpdconf 

service httpd restart

This pretty much it. All of this is required because you would lose all of your changes if you add them directly to your main httpd conf file.

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I have also create a simple script which can handle creation of reverse proxy config in cPanel

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