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Reading Pantheon Environment Configuration

Learn about the separation of configuration and code within Pantheon's runtime container environment.

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This section provides information on how to use database credentials for Object Cache (Redis) authentication.

You should never copy and paste credentials from your Dashboard into any of your site's code.

Database credentials, Object Cache authentication, and other configuration data is provided as part of the runtime container environment. It is present in PHP's $_ENV superglobal.

<?php var_dump($_ENV); ?>
array(13) {
  ["FRAMEWORK"]=>
  string(7) "drupal"
  ["DOCROOT"]=>
  string(1) "/"
  ["FILEMOUNT"]=>
  string(19) "sites/default/files"
  ["DRUPAL_HASH_SALT"]=>
  string(44) "xCoEVpEAOYv0OhG6QIpr+Z+oDIV+qwGcz79AAGssLlA="
  ["DB_HOST"]=>
  string(9) "XXX.XXX.XXX.XXX"
  etc...

The code you need to load this configuration and boot your app should already be pre-configured if you are using a common CMS framework. However, if you need any type of custom configuration, you can work with environmental configuration directly.

Platform Considerations

Connections will change from time to time due to the containerized nature of the platform. For security reasons, using the $_ENV superglobal inside PHP applications is not supported. As an alternative, consider using a Bash script and Terminus connection. You can view an example in the Create Secure Connection to MySQL using TLS documentation.

Drupal

Warning

Unless you're implementing Domain Access, using something other than the standard bootstrap process, or performing Drupal core development, you won't need to manually read the environment configuration. See configuring settings.php for details.

Pantheon uses Pressflow to automatically read the environmental configuration. If you're working with a vanilla Drupal site or want to pass the credentials and configuration such as the database credentials and temporary directory location to another application, you'll need to manually extract the configuration. You can do this in settings.php file in Drupal.

<?php
extract(json_decode($_SERVER['PRESSFLOW_SETTINGS'], TRUE));

Domain Access

Place Domain Access setup routine above any Object Cache configurations in settings.php. For example, in Drupal:

// All Pantheon Environments.
if (defined('PANTHEON_ENVIRONMENT')) {

  // Extract Pantheon environmental configuration for Domain Access
  extract(json_decode($_SERVER['PRESSFLOW_SETTINGS'], TRUE));
  // All $conf variables and Redis configuration go after extract()

  // If using Redis add appropriate settings per /docs/guides/object-cache/

  // Add other $conf variables, for example for Fast 404 pages

  /**
  * Add the domain module setup routine to the end of settings.php
  */
  include DRUPAL_ROOT . '/sites/all/modules/domain/settings.inc';
}
Note

Adding this snippet may cause the Status tab to show that Fast 404 pages are not enabled, when if configured properly, they actually are.

WordPress

Pantheon's default wp-config.php includes code to read from the $_ENV superglobal so no additional configuration should be required.

Refer to configuring wp-config.php for more information.

Hard-coded Directory References and $_ENV['HOME']

As a general best-practice, the home directory should be referenced through the $_ENV variable:

$_ENV['HOME']

Using $_SERVER

When incorporating custom configurations on Pantheon, use $_ENV instead of $_SERVER wherever possible. $_SERVER is generally unavailable when executing code via the command line (for example, Terminus, Drush, or WP-CLI), which can cause failures for things like clearing cache. The few exceptions include HTTP_HOST and REMOTE_ADDR, or things pertaining directly to the web request in progress such as redirects.

For debugging modules or plugins, it may be beneficial to review the values within the $_SERVER variable versus the value used by the plugin/module code. If $_SERVER variables are used, there may be instances where you need to alter the variable assignments to get a module or plugin to work properly as outlined in Server Name and Server Port.

Note

The $_SERVER variable contains sensitive data about a site and should not be publicly exposed. In the same way that you would not leave the output of phpinfo(); displayed on a site, don't leave this open to public viewing.

This is a partial example from a WordPress site homepage:

<?php var_dump($_SERVER);  ?>
array(63) {
    ["SERVER_SOFTWARE"]=>
    string(11) "nginx/1.4.7"
    ["REQUEST_URI"]=>
    string(1) "/"
    ["USER"]=>
    string(32) "non-static-binding-string-inserted-here"
    ["HOME"]=>
    string(46) "/"
    ["SCRIPT_NAME"]=>
    string(10) "/index.php"
    ["DOCUMENT_URI"]=>
    string(10) "/index.php"
    ["DOCUMENT_ROOT"]=>
    string(51) "/code"
    ["SERVER_PROTOCOL"]=>
    string(8) "HTTP/1.1"
    ["GATEWAY_INTERFACE"]=>
    string(7) "CGI/1.1"
    ["REMOTE_ADDR"]=>
    string(12) "72.188.192.8"  <= NOT A SITE IP ADDRESS
    ["REMOTE_PORT"]=>
    string(5) "55982"
    ["SERVER_ADDR"]=>
    string(13) "10.223.192.37"  <= NOT A SITE IP ADDRESS
    ["SERVER_PORT"]=>
    string(5) "11846"
    ["SERVER_NAME"]=>
    string(31) "endpointe7208f3b.chios.panth.io"
    ["REDIRECT_STATUS"]=>
    string(3) "200"
    ["PATH_TRANSLATED"]=>
    string(51) "/code"
    ["HTTPS"]=>
    string(3) "OFF"
    ["SCRIPT_FILENAME"]=>
    string(62) "/code//index.php"
    ["HTTP_HOST"]=>
    string(25) "example-wp-site.pantheonsite.io"
    ["HTTP_USER_AGENT"]=>
    string(120) "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/537.36 (KHTML, like Gecko)         Chrome/46.0.2490.80 Safari/537.36"
    ["HTTP_ACCEPT"]=>
    string(74) "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8"
    ["HTTP_ACCEPT_LANGUAGE"]=>
    string(14) "en-US,en;q=0.8"
    etc...
}

Setting Environment Variables

You can use the Terminus Secrets Manager Plugin to write the secrets to Pantheon's secure storage system. The secrets are encrypted at rest and follow all standard practices for the storing of sensitive values.

Learn more about this new feature by exploring our new Pantheon Secrets Guide:

More Resources