Resources for Developers

Deploying WordPress on Scalingo

Detection

When a PHP application is deployed, we’re looking if the wp-settings.php file is present at the root folder of your app.

During the deployment process you’ll see the following output, mentioning that the framework has correctly been detected.

-----> Detected WordPress
...
-----> Setting up WordPress

Configuration

By default WordPress uses a configuration file to configure a deployed application. In order to add environment variables support, you must edit the wp-config.php file to read the DATABASE_URL environment variable.

This can be done by adding those lines:

$mysql_url = parse_url($_ENV["DATABASE_URL"]);
$db = substr($mysql_url['path'], 1);

And changing the DB_* definitions to:

define('DB_NAME', $db);
define('DB_USER', $mysql_url['user']);
define('DB_PASSWORD', $mysql_url['pass']);
define('DB_HOST', $mysql_url['host'] . ":" . $mysql_url['port']);

You must do the same things for all your salts and keys. We recommend using a common environment variable and set it to a random string. You must adapt your wp-config.php to use this variable:

$key = $_ENV["SECURE_KEY"];
define('AUTH_KEY',         $key);
define('SECURE_AUTH_KEY',  $key);
define('LOGGED_IN_KEY',    $key);
define('NONCE_KEY',        $key);
define('AUTH_SALT',        $key);
define('SECURE_AUTH_SALT', $key);
define('LOGGED_IN_SALT',   $key);
define('NONCE_SALT',       $key);

The only thing left is to define the SECURE_KEY from the dashboard or by using our CLI:

scalingo -a myapp env-set SECURE_KEY=A_RANDOM_TOKEN_HERE

HTTPS

By default, WordPress tries to detect if the website is reached with HTTPS. However in an environment like Scalingo, applications are behind a routing layer which acts as proxy, which prevent WordPress to correctly detect the use of HTTPS.

To fix this problem, you need to add the following in your wp-config.php file (official documentation):

if (isset($_SERVER['HTTP_X_FORWARDED_PROTO']) && $_SERVER['HTTP_X_FORWARDED_PROTO'] == 'https')
    $_SERVER['HTTPS'] = 'on';

Thanks to this snippet, WordPress will look at the HTTP header X-Forwarded-Proto set by our router to ‘http’ or ‘https’ whether the website is accessed with HTTP or HTTPS. Have a look at our routing documentation for more information about this header.

Plugins and updates

Since the container file system is volatile, plugins and addon should be installed and updated within your Git repository and never via the web interface. You must de-activate auto-update of all your WordPress components.

To do that add the following line to your wp-config.php:

define( 'AUTOMATIC_UPDATER_DISABLED', true );

Uploads

The container file system is volatile and not synchronized through all your instances. So the uploads should not be stored on the file system itself. We recommend using an external service like the Amazon service: AWS S3 to store them.

You may want to have a look at a plugin such as S3 Uploads to ease the storage of your uploads on S3. As usual, this plugin must be downloaded locally and pushed to our Git repository, never via the web interface.


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