|
| 1 | +.. index:: |
| 2 | + single: Env |
| 3 | + single: Components; Env |
| 4 | + |
| 5 | +The Env Component |
| 6 | +================= |
| 7 | + |
| 8 | + The Env Component parses ``.env`` files to make environment variables |
| 9 | + stored in them accessible via ``getenv()``, ``$_ENV``, or ``$_SERVER``. |
| 10 | + |
| 11 | +Installation |
| 12 | +------------ |
| 13 | + |
| 14 | +You can install the component in 2 different ways: |
| 15 | + |
| 16 | +* :doc:`Install it via Composer </components/using_components>` (``symfony/env`` on `Packagist`_); |
| 17 | +* Use the official Git repository (https://github.com/symfony/env). |
| 18 | + |
| 19 | +.. include:: /components/require_autoload.rst.inc |
| 20 | + |
| 21 | +Usage |
| 22 | +----- |
| 23 | + |
| 24 | +Sensitive information and environment-dependent settings should be defined as |
| 25 | +environment variables (as recommended for `twelve-factor applications |
| 26 | +<http://www.12factor.net/>`_. Using an `.env` file to store those environment |
| 27 | +variables eases development and CI management by keeping them in one "standard" |
| 28 | +place and agnostic of the technology stack you are using (Nginx vs PHP build-in |
| 29 | +server for instance). |
| 30 | + |
| 31 | +.. note:: |
| 32 | + |
| 33 | + PHP has a lot of different implementation of this "pattern". This |
| 34 | + implementation goal is to replicate what ``source .env`` would do. So, it |
| 35 | + tries to be as similar as possible with the default shells behavior, and |
| 36 | + does not do anything not possible via ``source`` (like value validation). |
| 37 | + |
| 38 | +Usage |
| 39 | +----- |
| 40 | + |
| 41 | +First, require Symfony Env via Composer: |
| 42 | + |
| 43 | +.. code-block:: |
| 44 | +
|
| 45 | + composer require symfony/env |
| 46 | +
|
| 47 | +Load an ``.env`` file in your PHP application via ``Dotenv::load()``: |
| 48 | + |
| 49 | +.. code-block:: php |
| 50 | +
|
| 51 | + use Symfony\Component\Env\Dotenv; |
| 52 | +
|
| 53 | + $dotenv = new Dotenv(); |
| 54 | + $dotenv->load(__DIR__.'/.env'); |
| 55 | +
|
| 56 | + // You can also load several files |
| 57 | + $dotenv->load(__DIR__.'/.env', __DIR__.'/.env.dev'); |
| 58 | +
|
| 59 | +Given the following ``.env`` file content: |
| 60 | + |
| 61 | +.. code-block:: bash |
| 62 | +
|
| 63 | + DB_USER=root |
| 64 | + DB_PASS=pass |
| 65 | +
|
| 66 | +Access the value with ``getenv()`` in your code: |
| 67 | + |
| 68 | +.. code-block:: php |
| 69 | +
|
| 70 | + $dbUser = getenv('DB_USER); |
| 71 | + // you can also use ``$_ENV`` or ``$_SERVER`` |
| 72 | +
|
| 73 | +.. note:: |
| 74 | + |
| 75 | + Symfony Env never overwrites existing environment variables. |
| 76 | + |
| 77 | +You should never store a ``.env`` file is your code repository as it might |
| 78 | +contains sensitive information; creates a ``.env.dist`` file with sensible |
| 79 | +defaults instead. |
| 80 | + |
| 81 | +Symfony Env should only be used in development/testing/staging environments. |
| 82 | +For production environments, use "real" environment variables. |
| 83 | + |
| 84 | +As a ``.env`` file is a regular shell script, you can ``source`` it in your own |
| 85 | +shell scripts: |
| 86 | + |
| 87 | +.. code-block:: bash |
| 88 | +
|
| 89 | + source .env |
| 90 | +
|
| 91 | +Add comments by prefixing them with ``#``: |
| 92 | + |
| 93 | +.. code-block:: bash |
| 94 | +
|
| 95 | + # Database credentials |
| 96 | + DB_USER=root |
| 97 | + DB_PASS=pass # This is the secret password |
| 98 | +
|
| 99 | +Use environment variables in values by prefixing variables with ``$``: |
| 100 | + |
| 101 | +.. code-block:: bash |
| 102 | +
|
| 103 | + DB_USER=root |
| 104 | + DB_PASS=${DB_USER}pass # Include the user as a password prefix |
| 105 | +
|
| 106 | +Embed commands via ``$()``: |
| 107 | + |
| 108 | +.. code-block:: bash |
| 109 | +
|
| 110 | + START_TIME=$(date) |
| 111 | +
|
| 112 | +.. note:: |
| 113 | + |
| 114 | + Note that using ``$()`` might not work depending on your shell. |
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