Auto detect internal/external development environment

Question

We use the following function to auto detect if we are on a machine internally or on a live server and then choose the appropriate configs for various components:

Answer 1

Create and later look for a file that only exists on the live server's filesystem.

Granted, your environments should be as similar as possible; what I'm suggesting is something like this: in directory /var/environment/, have a file named {devel|test|qa|staging|live}, depending on the server you're on - then just check the filename.

Of course, you need to exclude this file from version control and from whatever build process you may have.

Answer 2

Set an environment variable in your Apache virtual host configuration. This is the way the Zend Framework does it.

See the ZF quick start guide for an example (the "Create a Virtual Host" section.)

In your httpd.conf or a .htaccess file, put:

SetEnv APPLICATION_ENV "development"

Then in your application, use the getenv function to get the value:

$environment = getenv("APPLICATION_ENV");
if ($environment == "development")
{
    // do development stuff
}
else if ($environment == "live")
{
    // do live stuff
}

Answer 3

'127.0.0.1' == $_SERVER["REMOTE_ADDR"]

This will never evaluate as TRUE on your live system. :)

Answer 4

Of course, if you have use virtual host locally like example.com then the function will be tricked.

Also if the host is not local but uses a widlcard or default vhost defn and the user adds the IP address to the hosts file locally.

I would recommend having a directory on the include path which also exists on live but is not replicated there - and simply store:

function getEnv(){
  return 'Live';
}

or

function getEnv(){
  return 'Test';
}

If both envs are on the same server - you can still do this by setting the include_path in Apache config or .htaccess.

This also allows you to seperate potentially sensitive env specific data - like database hosts/passwords and encyption keys.

C.

Answer 5

Adding to Andy Shellam's answer..

If you are using mod_vhost_alias, or have various domains with the same (virtual) document root, you can set the variable dependent upon parameters, e.g.

SetEnvIf SERVER_ADDR x.x.x.x APPLICATION_ENV=development
SetEnvIf HTTP_HOST abc.example.com APPLICATION_ENV=development