How to: Multi-site CodeIgniter Set-up
Written by: Phil Sturgeon
Hello, I am Phil and I have been developing websites since 1999. I started my career freelancing then ran a small web development team for over a year. Now I work as a developer for HargreavesLansdown and use my spare time to develop, write articles about programming and create slightly intoxicated screencasts. For more of my antics follow me on twitter @PhilSturgeon.In last nights Coder.eu chat session a few people suggested they would like to see a tutorial showing how to run CodeIgniter on multiple sites from the same code-base.
To get this working I took a little code from PyroCMS and modded a previous article “How to: Support multiple production environments in CodeIgniter” and found a relatively simple solution.
Setting the base URL
The first step of getting CodeIgniter working anywhere automatically is curing it of it’s most pointless configuration setting. It seems CodeIgniter would like to be told where it is, which really doesn’t need to happen. We could solve this in many ways, but instead of extending or replacing any core code, I would preffer to put a little snippet of code into the main application/config/config.php. Enter this code into the file and it will automatically support pretty much any kind of URL.
/*
|--------------------------------------------------------------------------
| Base Site URL
|--------------------------------------------------------------------------
|
| URL to your CodeIgniter root. Typically this will be your base URL,
| WITH a trailing slash:
|
| http://www.your-site.com/
|
*/
if(isset($_SERVER['HTTP_HOST']))
{
$config['base_url'] = isset($_SERVER['HTTPS']) && strtolower($_SERVER['HTTPS']) == 'on' ? 'https' : 'http';
$config['base_url'] .= '://'. $_SERVER['HTTP_HOST'];
$config['base_url'] .= str_replace(basename($_SERVER['SCRIPT_NAME']), '', $_SERVER['SCRIPT_NAME']);
}
else
{
$config['base_url'] = 'http://localhost/';
}
Setting a SITE constant
So the website URL is now set and links are fully working around the site. Next we need a way to work out throughout our code which site is currently being used. Amongst other things, this will help us with selecting the right database settings later.
/*
|--------------------------------------------------------------------------
| Site
| Set a constant for whichever site you happen to be running, if its not here
| it will fatal error.
|--------------------------------------------------------------------------
*/
switch($_SERVER['HTTP_HOST'])
{
case 'example.com':
case 'www.example.com':
define('SITE', 'example');
break;
case 'example2.com':
case 'www.example2.com':
define('SITE', 'example2');
break;
default:
define('SITE', 'default');
break;
}
Domain based database settings
Now that CodeIgniter has its links working and it knows what site it is trying to run, it needs to know the database configuration for this domain. To do that, we can break down our config into domain specific “Database groups”.
< ?php if (!defined('BASEPATH')) exit('No direct script access allowed');
/*
| -------------------------------------------------------------------
| DATABASE CONNECTIVITY SETTINGS
| -------------------------------------------------------------------
| This file will contain the settings needed to access your database.
|
| For complete instructions please consult the "Database Connection"
| page of the User Guide.
|
| -------------------------------------------------------------------
| EXPLANATION OF VARIABLES
| -------------------------------------------------------------------
|
| ['hostname'] The hostname of your database server.
| ['username'] The username used to connect to the database
| ['password'] The password used to connect to the database
| ['database'] The name of the database you want to connect to
| ['dbdriver'] The database type. ie: mysql. Currently supported:
mysql, mysqli, postgre, odbc, mssql
| ['dbprefix'] You can add an optional prefix, which will be added
| to the table name when using the Active Record class
| ['pconnect'] TRUE/FALSE - Whether to use a persistent connection
| ['db_debug'] TRUE/FALSE - Whether database errors should be displayed.
| ['active_r'] TRUE/FALSE - Whether to load the active record class
| ['cache_on'] TRUE/FALSE - Enables/disables query caching
| ['cachedir'] The path to the folder where cache files should be stored
|
| The $active_group variable lets you choose which connection group to
| make active. By default there is only one group (the "default" group).
|
*/
$active_record = TRUE;
$db['default']['hostname'] = "localhost";
$db['default']['username'] = "";
$db['default']['password'] = "";
$db['default']['database'] = "";
$db['default']['dbdriver'] = "mysql";
$db['default']['dbprefix'] = "";
$db['default']['pconnect'] = TRUE;
$db['default']['db_debug'] = TRUE;
$db['default']['cache_on'] = FALSE;
$db['default']['cachedir'] = "";
$db['default']['char_set'] = "utf8";
$db['default']['dbcollat'] = "utf8_general_ci";
// example
$db['example']['hostname'] = "localhost";
$db['example']['username'] = "root";
$db['example']['password'] = "";
$db['example']['database'] = "example";
$db['example']['dbdriver'] = "mysql";
$db['example']['dbprefix'] = "";
$db['example']['active_r'] = TRUE;
$db['example']['pconnect'] = TRUE;
$db['example']['db_debug'] = TRUE;
$db['example']['cache_on'] = FALSE;
$db['example']['cachedir'] = "";
$db['example']['char_set'] = "utf8";
$db['example']['dbcollat'] = "utf8_general_ci";
// Example 2
$db['example2']['hostname'] = "localhost";
$db['example2']['username'] = "root";
$db['example2']['password'] = "root";
$db['example2']['database'] = "testfoo";
$db['example2']['dbdriver'] = "mysql";
$db['example2']['dbprefix'] = "";
$db['example2']['active_r'] = TRUE;
$db['example2']['pconnect'] = TRUE;
$db['example2']['db_debug'] = TRUE;
$db['example2']['cache_on'] = FALSE;
$db['example2']['cachedir'] = "";
$db['example2']['char_set'] = "utf8";
$db['example2']['dbcollat'] = "utf8_general_ci";
// Check the configuration group in use exists, if not use the default
$active_group = (defined('SITE') && array_key_exists(SITE, $db)) ? SITE : 'default';
?>
The little snippet of code at the bottom will check to see if the SITE constant you have set matches up with a database group. If it doesn’t, it will use the default configuration group.
Your CodeIgniter set-up should now work with any domain you happen to point to it. You even run simple little
if(SITE == 'example2')
checks anywhere within your code to do special code for a certian site, although I would not reccomend you doing this too heavily.
Tags: CodeIgniter, PHP, tutorial
This posts latest comments
The most dumb tutorial ever.
If you’re going to post something, at least post something useful instead of being a Troll.
I meant dumb because the tutorial states obvious things.
And for the $_SERVER['HTTP_HOST'] solution:
This solution won’t work for multidomain hosts and for raw IPs and even if you fill in all possible values you can’t be sure IP is still valid after some time (it can change).
The most simple solution is to add site designation into small text file (ie. site/site.txt) or even a folder name. Every time you update site files this one doesn’t change. Even when the site is accessed using other valid domain name the site works because it doesn’t guess. It still works even if IP changes.
You have missed the point of this entirely. If you use a raw IP to access your website or have multiple domains accessing the same content, then you would not want to be doing this. This is a tutorial explaining how you can run one code-base with multiple domains accessing different content.
If your IP changes, it doesn’t matter as you are using the HTTP_HOST setting which uses the domain name. HTTP_HOST is a standard $_SERVER item and will be populated by any standard Apache installation. The only time I have known it to be missing is accessing PHP via the command line and of course I had no expectation for it to be there.
I thank you for your suggestions but you have clearly misunderstood what this tutorial was meant to achieve. Perhaps you could write up a tutorial explaining your goals and methods for us to publish here?
Update: Thinking about it the example already shows you how different domains can access the same content or different content. It is all based on the cases set in the database.php config file. example.com and http://www.example.com could be replaced with examplea.com and exampleb.com. They would be different domains looking at the same data, while the other cases in the switch are looking for different domains and different data.
Ok. So you should write it is for the same CODE-BASE FILES and not for just several CODE-BASE copies. I misunderstood you want to copy your code-base files to different servers and not just one server.
The article was aimed at having a single shared codebase with several domains pointing to it, but of course, you could do either as this code would work either way.