How do I run multiple websites on the same server with the same code base in PHP?

Question

I have created a custom, specialized CMS with a number of clients on it, each with their own domain name, website, admin area and database, but all residing on the same server.

Whenever I get a new client, I simply copy all of the code over, change 3 lines in a config file, and then all of their styles/data is taken out of the database or from uploads they post to the server from their own admin area.

Sounds great so far right?

Well when I recently decided to update all of the clients sites, this became a major pain. Obviously i had to change the code on each install. For a major update this is fine, but for frequent tweaks or the like, duplicating the effort of uploading becomes very annoying....I hope to someday have dozens or hundreds of clients, so the code will eventually have to be centralized so that changing it in one place updates it everywhere...how does one do that?

Answer 1

A easy solution would be to put the source code in a subdirectory, except the files, which should be altered for each client (for example, the config file).

You can then put this source code directory somewhere out and just create symlinks to it.

For example, your directory structure might look like:

/var/www/src/index.php
/var/www/src/more_source.php
/var/www/clients/client_a/settings.php
/var/www/clients/client_a/src -> ../../src/
/var/www/clients/client_b/settings.php
/var/www/clients/client_b/src -> ../../src/

If you choose this structure, the only thing you would need to change, would be the include for settings.php (e.g. from require "settings.php" to require "../settings.php").

Answer 2

Personally, I have a client table on the database that holds the current version number of the code that they're running. When a user logs in, it sets a cookie called CodeVersion indicating the code version for that client (e.g. "v5-09-00"). In the Apache .htaccess, I have:

RewriteEngine on

RewriteCond %{HTTP_COOKIE} CodeVersion=([^;]+) [NC]
RewriteRule ^(.*)$ http://v%1.%{HTTP_HOST}/${escape:$1} [R=302,P,L]

and within the local hosts file, I have:

127.0.0.1    myservername       myservername.myserverdomain.com

127.0.0.1    v5-08-00.myservername  v5-08-00.myservername.myserverdomain.com
127.0.0.1    v5-09-00.myservername  v5-09-00.myservername.myserverdomain.com
127.0.0.1    v5-10-00.myservername  v5-10-00.myservername.myserverdomain.com

which handles local redirection within Apache to an entry in vhosts

The vhosts file sets the environment for each version of the code:

<VirtualHost *:80>
    ServerAdmin [email protected]
    DocumentRoot /usr/local/apache/htdocs_5-09-00
    ServerName v5-09-00.myservername.myserverdomain.com
    ServerAlias v5-09-00.myservername
    ErrorLog logs/myservername-error_log_5-09-00
    CustomLog logs/myservername-access_log_5-09-00 common
    php_value include_path ".:/php/includes:/usr/local/include/5-09-00/API:/usr/local/include/5-09-00/library:/usr/local/include/5-09-00/businesslogic:/usr/local/include/5-09-00/configuration:/usr/local/include/5-09-00/library/PHPExcel/Classes"
</VirtualHost>

<Directory "/usr/local/apache/htdocs_5-09-00">
    Options Indexes FollowSymLinks ExecCGI
    AllowOverride All
    Order allow,deny
    Allow from all
</Directory>

Within each set of directories, I can have symbolic links pointing to common code, and actual php/ini files for client-specific code or configuration.