silverstripe-framework/docs/en/00_Getting_Started/03_Environment_Management.md

Environment management

As part of website development and hosting it is natural for our sites to be hosted on several different environments. These can be our laptops for local development, a testing server for customers to test changes on, or a production server.

For each of these environments we may require slightly different configurations for our servers. This could be our debug level, caching backends, or - of course - sensitive information such as database credentials.

To solve this problem of setting variables per environment we use environment variables with the help of the PHPDotEnv library by Vance Lucas.

Security considerations

Sensitive credentials should not be stored in a VCS or project code and should only be stored on the environment in question. When using live environments the use of .env files is discouraged and instead one should use "first class" environment variables.

If you do use a .env file on your servers, you must ensure that external access to .env files is blocked by the webserver.

Managing environment variables with .env files

By default the .env must be placed in your project root (ie: same folder as you composer.json) or the parent directory. If this file exists, it will be automatically loaded by the framework and the environment variables will be set. An example .env file is included in the default installer named.env.example.

Managing environment variables with Apache

You can set "real" environment variables using Apache. Please see the Apache docs for more information

How to access the environment variables

Accessing the environment varaibles is easy and can be done using the getenv method or in the $_ENV and $_SERVER super-globals:

getenv('SS_DATABASE_CLASS');
$_ENV['SS_DATABASE_CLASS'];
$_SERVER['SS_DATABASE_CLASS'];

Including an extra .env file

Sometimes it may be useful to include an extra .env file - on a shared local development environment where all database credentials could be the same. To do this, you can add this snippet to your mysite/_config.php file:

try {
	(new \Dotenv\Dotenv('/path/to/env/'))->load();
} catch (\Dotenv\Exception\InvalidPathException $e) {
	// no file found
}

Core environment variables

SilverStripe core environment variables are listed here, though you're free to define any you need for your application.

Name	Description
SS_DATABASE_CLASS	The database class to use, MySQLPDODatabase, MySQLDatabase, MSSQLDatabase, etc. defaults to MySQLPDODatabase.
SS_DATABASE_SERVER	The database server to use, defaulting to localhost.
SS_DATABASE_USERNAME	The database username (mandatory).
SS_DATABASE_PASSWORD	The database password (mandatory).
SS_DATABASE_PORT	The database port.
SS_DATABASE_SUFFIX	A suffix to add to the database name.
SS_DATABASE_PREFIX	A prefix to add to the database name.
SS_DATABASE_TIMEZONE	Set the database timezone to something other than the system timezone.
SS_DATABASE_NAME	Set the database name. Assumes the $database global variable in your config is missing or empty.
SS_DATABASE_CHOOSE_NAME	Boolean/Int. If defined, then the system will choose a default database name for you if one isn't give in the $database variable. The database name will be "SS_" followed by the name of the folder into which you have installed SilverStripe. If this is enabled, it means that the phpinstaller will work out of the box without the installer needing to alter any files. This helps prevent accidental changes to the environment. If SS_DATABASE_CHOOSE_NAME is an integer greater than one, then an ancestor folder will be used for the database name. This is handy for a site that's hosted from /sites/examplesite/www or /buildbot/allmodules-2.3/build. If it's 2, the parent folder will be chosen; if it's 3 the grandparent, and so on.
SS_DEPRECATION_ENABLED	Enable deprecation notices for this environment.
SS_ENVIRONMENT_TYPE	The environment type: dev, test or live.
SS_DEFAULT_ADMIN_USERNAME	The username of the default admin. This is a user with administrative privileges.
SS_DEFAULT_ADMIN_PASSWORD	The password of the default admin. This will not be stored in the database.
SS_USE_BASIC_AUTH	Protect the site with basic auth (good for test sites). When using CGI/FastCGI with Apache, you will have to add the RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}] rewrite rule to your .htaccess file
SS_SEND_ALL_EMAILS_TO	If you define this constant, all emails will be redirected to this address.
SS_SEND_ALL_EMAILS_FROM	If you define this constant, all emails will be sent from this address.
SS_ERROR_LOG	Relative path to the log file.
SS_PROTECTED_ASSETS_PATH	Path to secured assets - defaults to ASSET_PATH/.protected
SS_DATABASE_MEMORY	Used for SQLite3 DBs
SS_TRUSTED_PROXY_IPS	IP address or CIDR range to trust proxy headers from. If left blank no proxy headers are trusted. Can be set to 'none' (trust none) or '*' (trust all)
SS_ALLOWED_HOSTS	A comma deliminated list of hostnames the site is allowed to respond to
SS_MANIFESTCACHE	The manifest cache to use (defaults to file based caching). Must be a CacheInterface or CacheFactory class name
SS_IGNORE_DOT_ENV	If set the .env file will be ignored. This is good for live to mitigate any performance implications of loading the .env file
SS_BASE_URL	The url to use when it isn't determinable by other means (eg: for CLI commands)