Awesome
PHP dotenv
Loads environment variables from .env
to getenv()
, $_ENV
and $_SERVER
automagically.
Why .env?
You should never store sensitive credentials in your code. Storing configuration in the environment is one of the tenets of a twelve-factor app. Anything that is likely to change between deployment environments – such as database credentials or credentials for 3rd party services – should be extracted from the code into environment variables.
Basically, a .env
file is an easy way to load custom configuration variables
that your application needs without having to modify .htaccess files or
Apache/nginx virtual hosts. This means you won't have to edit any files outside
the project, and all the environment variables are always set no matter how you
run your project - Apache, Nginx, CLI, and even PHP's built-in webserver. It's
WAY easier than all the other ways you know of to set environment variables,
and you're going to love it!
- NO editing virtual hosts in Apache or Nginx
- NO adding
php_value
flags to .htaccess files - EASY portability and sharing of required ENV values
- COMPATIBLE with PHP's built-in web server and CLI runner
PHP dotenv is a PHP version of the original Ruby dotenv.
Installation
Installation is super-easy via Composer:
$ composer require vlucas/phpdotenv
or add it by hand to your composer.json
file.
Upgrading
We follow semantic versioning, which means breaking changes may occur between major releases. We have upgrading guides available for V2 to V3, V3 to V4 and V4 to V5 available here.
Usage
The .env
file is generally kept out of version control since it can contain
sensitive API keys and passwords. A separate .env.example
file is created
with all the required environment variables defined except for the sensitive
ones, which are either user-supplied for their own development environments or
are communicated elsewhere to project collaborators. The project collaborators
then independently copy the .env.example
file to a local .env
and ensure
all the settings are correct for their local environment, filling in the secret
keys or providing their own values when necessary. In this usage, the .env
file should be added to the project's .gitignore
file so that it will never
be committed by collaborators. This usage ensures that no sensitive passwords
or API keys will ever be in the version control history so there is less risk
of a security breach, and production values will never have to be shared with
all project collaborators.
Add your application configuration to a .env
file in the root of your
project. Make sure the .env
file is added to your .gitignore
so it is not
checked-in the code
S3_BUCKET="dotenv"
SECRET_KEY="souper_seekret_key"
Now create a file named .env.example
and check this into the project. This
should have the ENV variables you need to have set, but the values should
either be blank or filled with dummy data. The idea is to let people know what
variables are required, but not give them the sensitive production values.
S3_BUCKET="devbucket"
SECRET_KEY="abc123"
You can then load .env
in your application with:
$dotenv = Dotenv\Dotenv::createImmutable(__DIR__);
$dotenv->load();
To suppress the exception that is thrown when there is no .env
file, you can:
$dotenv = Dotenv\Dotenv::createImmutable(__DIR__);
$dotenv->safeLoad();
Optionally you can pass in a filename as the second parameter, if you would
like to use something other than .env
:
$dotenv = Dotenv\Dotenv::createImmutable(__DIR__, 'myconfig');
$dotenv->load();
All of the defined variables are now available in the $_ENV
and $_SERVER
super-globals.
$s3_bucket = $_ENV['S3_BUCKET'];
$s3_bucket = $_SERVER['S3_BUCKET'];
Putenv and Getenv
Using getenv()
and putenv()
is strongly discouraged due to the fact that
these functions are not thread safe, however it is still possible to instruct
PHP dotenv to use these functions. Instead of calling
Dotenv::createImmutable
, one can call Dotenv::createUnsafeImmutable
, which
will add the PutenvAdapter
behind the scenes. Your environment variables will
now be available using the getenv
method, as well as the super-globals:
$s3_bucket = getenv('S3_BUCKET');
$s3_bucket = $_ENV['S3_BUCKET'];
$s3_bucket = $_SERVER['S3_BUCKET'];
Nesting Variables
It's possible to nest an environment variable within another, useful to cut down on repetition.
This is done by wrapping an existing environment variable in ${…}
e.g.
BASE_DIR="/var/webroot/project-root"
CACHE_DIR="${BASE_DIR}/cache"
TMP_DIR="${BASE_DIR}/tmp"
Immutability and Repository Customization
Immutability refers to if Dotenv is allowed to overwrite existing environment
variables. If you want Dotenv to overwrite existing environment variables,
use createMutable
instead of createImmutable
:
$dotenv = Dotenv\Dotenv::createMutable(__DIR__);
$dotenv->load();
Behind the scenes, this is instructing the "repository" to allow immutability
or not. By default, the repository is configured to allow overwriting existing
values by default, which is relevant if one is calling the "create" method
using the RepositoryBuilder
to construct a more custom repository:
$repository = Dotenv\Repository\RepositoryBuilder::createWithNoAdapters()
->addAdapter(Dotenv\Repository\Adapter\EnvConstAdapter::class)
->addWriter(Dotenv\Repository\Adapter\PutenvAdapter::class)
->immutable()
->make();
$dotenv = Dotenv\Dotenv::create($repository, __DIR__);
$dotenv->load();
The above example will write loaded values to $_ENV
and putenv
, but when
interpolating environment variables, we'll only read from $_ENV
. Moreover, it
will never replace any variables already set before loading the file.
By means of another example, one can also specify a set of variables to be allow listed. That is, only the variables in the allow list will be loaded:
$repository = Dotenv\Repository\RepositoryBuilder::createWithDefaultAdapters()
->allowList(['FOO', 'BAR'])
->make();
$dotenv = Dotenv\Dotenv::create($repository, __DIR__);
$dotenv->load();
Requiring Variables to be Set
PHP dotenv has built in validation functionality, including for enforcing the presence of an environment variable. This is particularly useful to let people know any explicit required variables that your app will not work without.
You can use a single string:
$dotenv->required('DATABASE_DSN');
Or an array of strings:
$dotenv->required(['DB_HOST', 'DB_NAME', 'DB_USER', 'DB_PASS']);
If any ENV vars are missing, Dotenv will throw a RuntimeException
like this:
One or more environment variables failed assertions: DATABASE_DSN is missing
Empty Variables
Beyond simply requiring a variable to be set, you might also need to ensure the variable is not empty:
$dotenv->required('DATABASE_DSN')->notEmpty();
If the environment variable is empty, you'd get an Exception:
One or more environment variables failed assertions: DATABASE_DSN is empty
Integer Variables
You might also need to ensure that the variable is of an integer value. You may do the following:
$dotenv->required('FOO')->isInteger();
If the environment variable is not an integer, you'd get an Exception:
One or more environment variables failed assertions: FOO is not an integer.
One may only want to enforce validation rules when a variable is set. We support this too:
$dotenv->ifPresent('FOO')->isInteger();
Boolean Variables
You may need to ensure a variable is in the form of a boolean, accepting "true", "false", "On", "1", "Yes", "Off", "0" and "No". You may do the following:
$dotenv->required('FOO')->isBoolean();
If the environment variable is not a boolean, you'd get an Exception:
One or more environment variables failed assertions: FOO is not a boolean.
Similarly, one may write:
$dotenv->ifPresent('FOO')->isBoolean();
Allowed Values
It is also possible to define a set of values that your environment variable should be. This is especially useful in situations where only a handful of options or drivers are actually supported by your code:
$dotenv->required('SESSION_STORE')->allowedValues(['Filesystem', 'Memcached']);
If the environment variable wasn't in this list of allowed values, you'd get a similar Exception:
One or more environment variables failed assertions: SESSION_STORE is not an allowed value.
It is also possible to define a regex that your environment variable should be.
$dotenv->required('FOO')->allowedRegexValues('([[:lower:]]{3})');
Comments
You can comment your .env
file using the #
character. E.g.
# this is a comment
VAR="value" # comment
VAR=value # comment
Parsing Without Loading
Sometimes you just wanna parse the file and resolve the nested environment variables, by giving us a string, and have an array returned back to you. While this is already possible, it is a little fiddly, so we have provided a direct way to do this:
// ['FOO' => 'Bar', 'BAZ' => 'Hello Bar']
Dotenv\Dotenv::parse("FOO=Bar\nBAZ=\"Hello \${FOO}\"");
This is exactly the same as:
Dotenv\Dotenv::createArrayBacked(__DIR__)->load();
only, instead of providing the directory to find the file, you have directly provided the file contents.
Usage Notes
When a new developer clones your codebase, they will have an additional
one-time step to manually copy the .env.example
file to .env
and fill-in
their own values (or get any sensitive values from a project co-worker).
Troubleshooting
In certain server setups (most commonly found in shared hosting), PHP might deactivate superglobals like $_ENV
or $_SERVER
. If these variables are not set, review the variables_order
in the php.ini
file. See php.net/manual/en/ini.core.php#ini.variables-order.
Security
If you discover a security vulnerability within this package, please send an email to security@tidelift.com. All security vulnerabilities will be promptly addressed. You may view our full security policy here.
License
PHP dotenv is licensed under The BSD 3-Clause License.
For Enterprise
Available as part of the Tidelift Subscription
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and thousands of other packages are working with Tidelift to deliver commercial support and maintenance for the open source dependencies you use to build your applications. Save time, reduce risk, and improve code health, while paying the maintainers of the exact dependencies you use. Learn more.