Single Codeigniter Code Base for Multiple Domains - php

Question

I'm looking for a clear explanation of how to use CodeIgniter for multiple domains. I want a single set of models and config files, with the ability to call different controllers depending on the domain the request is coming from. After doing some research, I am fairly certain the way I currently have this set up is not ideal, and I would like to fix it before I get too far into building. Here's the current set up:
I have three domains that I'm managing:
domainA.com
domainB.com
domainC.com
Each domain points to a different folder on my server:
/domains
/global
/models
/model1.php
/model2.php
/domainA.com <--- domainA.com points here
/application
/controllers
/domainAController1.php
/domainAController2.php
/assets
/system
/index.php
/domainB.com <--- domainB.com points here
/application
/controllers
/domainBController1.php
/domainBController2.php
/assets
/system
/index.php
/domainC.com <--- domainC.com points here
/application
/controllers
/domainCController1.php
/domainCController2.php
/assets
/system
/index.php
Then, in each controller, I add a package path in the constructor function so that the controllers have access to my global models:
$this->load->add_package_path(APPPATH.'../../global/');
This allows me to load models from the controllers as normal with something like:
$this->load->model('model1');
The folder hierarchy I'm showing above is not complete. Inside each of the domain folders, there is a full CI installation. So if I want to define constants or configuration parameters for the entire "app", I essentially have to do it three times. Also, the more I develop, the more I am coming across needs for more advanced features like base models and controllers and I have a feeling this "package path" solution I"m using now is not going to work.
This clearly is not the right way to go about it, and I was hoping someone could offer me a better way to implement this.
I am running CodeIgniter version 2.1.4.
***************************UPDATE***************************
Here's what I ended up doing to get this working. I would love someone's advice on if this is a good or bad idea, meaning, do you foresee any obvious issues using this method?
I used routes and controller subfolders to accomplish what I needed. I now have a single installation of CI, and within my controllers folder I have subfolders for domainA.com, domainB.com and domainC.com.
Then, in my routes.php file, I added this after the reserved routes:
switch($_SERVER['SERVER_NAME']){
case 'domainA.com':
$controllerSubDirectory = 'domainA.com';
break;
case 'domainB.com':
$controllerSubDirectory = 'domainB.com';
break;
case 'domainC.com':
$controllerSubDirectory = 'domainC.com';
break;
default:
$controllerSubDirectory = '';
break;
}
route['(.*)'] = "{$controllerSubDirectory}/$1";
In other words, I just take the incoming request and route it as if it were actually coming in with the appropriate subfolder as it's first URI segment.
Are there any issues with this I am not thinking of? Maybe some sort of security risks?

Answer 1

The short answer: take advantage of CodeIgniter "Third Party Packages" feature.
Your directory structure is not very well organized. It is not necessary to store multiple copies of the CodeIgniter System files, assuming of course that all applications are using the same system (version and no/same modifications to core files).
Check CodeIgniter Docs for more detail.
As mentioned above, you could take advantage of CI's packages to package your common code as a 3rd party package. Then you can just load models and other resources as you normally would, and CI will know how to find them on it's own.