The Dotenv Component
The Dotenv Component¶
The Dotenv Component parses.env
files to make environment variables stored in them accessible viagetenv()
,$_ENV
or$_SERVER
.
New in version 3.3: The Dotenv component was introduced in Symfony 3.3.
Installation¶
You can install the component in 2 different ways:
- Install it via Composer (
symfony/dotenv
on Packagist); - Use the official Git repository (https://github.com/symfony/dotenv).
Then, require the vendor/autoload.php
file to enable the autoloading mechanism
provided by Composer. Otherwise, your application won't be able to find the classes
of this Symfony component.
Usage¶
Sensitive information and environment-dependent settings should be defined as
environment variables (as recommended for twelve-factor applications). Using
a .env
file to store those environment variables eases development and CI
management by keeping them in one "standard" place and agnostic of the
technology stack you are using (Nginx vs PHP built-in server for instance).
Note
PHP has a lot of different implementations of this "pattern". This
implementation's goal is to replicate what source .env
would do. It
tries to be as similar as possible with the standard shell's behavior (so
no value validation for instance).
Load a .env
file in your PHP application via Dotenv::load()
:
1 2 3 4 5 6 7 | use Symfony\Component\Dotenv\Dotenv;
$dotenv = new Dotenv();
$dotenv->load(__DIR__.'/.env');
// You can also load several files
$dotenv->load(__DIR__.'/.env', __DIR__.'/.env.dev');
|
Given the following .env
file content:
1 2 3 | # .env
DB_USER=root
DB_PASS=pass
|
Access the value with getenv()
in your code:
$dbUser = getenv('DB_USER');
// you can also use ``$_ENV`` or ``$_SERVER``
Note
Symfony Dotenv never overwrites existing environment variables.
You should never store a .env
file in your code repository as it might
contain sensitive information; create a .env.dist
file with sensible
defaults instead.
Symfony Dotenv should only be used in development/testing/staging environments. For production environments, use "real" environment variables.
As a .env
file is a regular shell script, you can source
it in your own
shell scripts:
1 | source .env
|
Add comments by prefixing them with #
:
1 2 3 | # Database credentials
DB_USER=root
DB_PASS=pass # This is the secret password
|
Use environment variables in values by prefixing variables with $
:
1 2 | DB_USER=root
DB_PASS=${DB_USER}pass # Include the user as a password prefix
|
Embed commands via $()
(not supported on Windows):
1 | START_TIME=$(date)
|
Note
Note that using $()
might not work depending on your shell.
This work, including the code samples, is licensed under a Creative Commons BY-SA 3.0 license.