This document contains information about using Cloud Platform environment variables in your application.

Cloud Platform makes environment variables available for your use in both your application code and Drush commands. With these variables, you can write code that responds to the environment in which it runs. For example, you may want to run certain commands only in your production environment, but not in the development or staging environment.

Additional environment variables are available for Pipelines.

if (file_exists('/var/www/site-php')) {
   require '/var/www/site-php/sitename/sitename-settings.inc';
  }

In addition to the environment variables provided by Cloud Platform, you can provide information to your application by creating custom environment variables in the Cloud Platform interface, or by storing private information in the file system.

Available environment variables¶

Cloud Platform includes the following environment variables:

Environment variables in .htaccess¶

You can also use environment variables in your .htaccess file. In the following example, we redirect HTTP requests to HTTPS only on the production environment, and not in the development or staging environments:

RewriteCond %{HTTPS} off
RewriteCond %{HTTP:X-Forwarded-Proto} !https
RewriteCond %{ENV:AH_SITE_ENVIRONMENT} prod
// Site Factory may require a different value for
// %{ENV:AH_SITE_ENVIRONMENT} depending on site configuration
RewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]

For more information, see Excluding Acquia domains and non-production environments.

Faking your environment variables for local testing¶

During testing, you may want to force a Cloud Platform environment variable to contain a specific value by making a change to your local settings.php file. The following example sets the AH_SITE_ENVIRONMENT variable to the dev environment:

$_ENV['AH_SITE_ENVIRONMENT'] = 'dev';

For an example of this technique’s use, see Overriding Solr index connection switching.

Examples¶

For example, the following statement would let you switch code based on the environment:

if (isset($_ENV['AH_SITE_ENVIRONMENT'])) {
   switch ($_ENV['AH_SITE_ENVIRONMENT']) {
     case 'dev':
       // do something on dev
       break;
     case 'test':
       // do something on staging
       break;
     case 'prod':
       // do something on prod
       // Site Factory may require a different value depending
       // on site configuration
       break;
     case 'ra':
       // do something on ra - necessary if a
       // Remote Administration environment is present
       break;
     }
    }
    else {
    // do something for a non-Acquia-hosted application
    // (like a local dev install).
; }

To make Acquia Search read-only on your Development and Staging environments, so the search index doesn’t have duplicate copies of content:

// place this after the Acquia require line
if (!isset($_ENV['AH_SITE_ENVIRONMENT'])  ||
  'prod' != $_ENV['AH_SITE_ENVIRONMENT'])     {
  $settings['acquia_search']['read_only'] = TRUE;
}

For another example, see Setting base URLs.