Laravel Unleash

A simple Unleash component for Laravel. It is compatible with the Unlesah-hosted.com SaaS offering, Unleash Open-Source, and GitLab's Feature Flag system, which is built on Unleash.

V2 of this package is a wrapper and extension of the Unleash PHP SDK that is compatible with Laravel.

Getting started

1. Install the Laravel Unleash via Composer

composer require j-webb/laravel-unleash

2. Configure

Create local configuration (optional)

php artisan vendor:publish --provider="JWebb\Unleash\Providers\ServiceProvider"

Required .env values

# Your Unleash instance endpoint
UNLEASH_URL=https://app.unleash-hosted.com/

Optional .env values

# Enable or disable the Laravel Unleash client. If disabled, all feature checks will return false
UNLEASH_ENABLED=true

# For compatibility with Unleash V4, or other authentcation methods. Appends itself to the `Authorization` header for each request
UNLEASH_API_KEY=123456

# Instance id for this application (typically hostname, podId or similar)
UNLEASH_INSTANCE_ID=default 

# The Unleash environment name, which can be used to as a parameter for enabling/disabling features for local or development environments
# See: https://docs.getunleash.io/advanced/strategy_constraints#constrain-on-a-specific-environment
UNLEASH_ENVIRONMENT=production 

# Automatically registers the client instance with the unleash server
UNLEASH_AUTOMATIC_REGISTRATION=true 

# Enable/Disable metrics
UNLEASH_METRICS=true 

# Enable/Disable failsafe cache for data
# See: https://docs.getunleash.io/client-specification#system-overview
UNLEASH_CACHE_ENABLED=true 
UNLEASH_CACHE_TTL=30 

Setting up the Middleware

The module comes bundled with middleware for you to perform a feature check on routes and/or controllers.

#/app/Http/Kernal.php
protected $routeMiddleware = [
    ...
    'feature' => \JWebb\Unleash\Middleware\CheckFeature::class,
    ...
];

Once added to your Kernal.php file, you can use this in any area where middleware is applicable. As an example, you could use this in a controller.

public function __construct()
{
    $this->middleware('feature:your_feature_name');
}

See the Laravel Docs for more information.

Setting up a custom cache handler

If the cache option is enabled, by default the component will use the Laravel Cache module. By utilizing the UnleashCacheHandlerInterface, you can create your own PSR-16 compatible implementation and override the unleash.cache.handler config value with your handler class.

Setting up custom strategies

To add your own strategy, you can override or create your own Strategies Provider. A UnleashStrategiesProviderInterface is included for convenience. Once your custom class is build, you should modify the unleash.strategy_provider config value.

Usage

Checking individual features

if (Unleash::isEnabled('your_feature')) {
    // Your feature is enabled
}

Using array of features.

// List of all features, enabled or disabled
$allFeatures = Unleash::getFeatures();
Result: [
    'toggles' => [
        'feature_1' => [
            'enabled' => true,
            'name' => 'feature_1'
        ],
        'feature_2' => [
            'enabled' => false,
            'name' => 'feature_2'
        ]
    ]
]

// List of all enabled features
$enabledFeatures = Unleash::getFeatures(true);
Result: [
    'toggles' => [
        'feature_1' => [
            'enabled' => true,
            'name' => 'feature_1'
        ]
    ]
]

Note: The result matches that which would be returned from the official Unleash Proxy instances. This means you could use your Laravel application as an Unleash Proxy endpoint, which is compatible with the official client-side Unleash Proxy SDKs

Using middleware on a controller

class ExampleController extends Controller
{
    public function __construct()
    {
        ...
        $this->middleware('feature:your_feature');
    }
}

Using middleware on a route

Route::get('/', function () {
    //
})->middleware('feature:your_feature');

Because the component is a wrapper of the official Unleash Client SDK, you can pass relevant context to your checks:

$context = (new UnleashContext())
    ->setCurrentUserId('some-user-id-from-app')
    ->setIpAddress('127.0.0.1')
    ->setSessionId('sess-123456');
$enabled = Unleash::isEnabled('some-feature', $context);

Note: User ID information is automatically added to the context using the Laravel Auth module

Or get variant information

$variant = $unleash->getVariant('nonexistentFeature');
assert($variant->isEnabled() === false);