Overwatch

This package allows you to define custom metrics for a Laravel application and retrieve them either through an HTTP request or a command.

Installation

You can install the package via composer:

composer require modernmcguire/overwatch

To create a new overwatch secret key for your application, use the following command:

php artisan overwatch:generate

You can publish the config file with:

php artisan vendor:publish --tag="overwatch-config"

This is the contents of the published config file which will include the laravel and php version by default:

<?php

use Modernmcguire\Overwatch\Metrics\PhpVersion;
use Modernmcguire\Overwatch\Metrics\LaravelVersion;

return [

    'secret' => env('OVERWATCH_SECRET'),

    'metrics' => [
        PhpVersion::class,
        LaravelVersion::class,
    ],
];

Usage

Overwatch works by querying your application for Metrics that you want to track. You can create your own metrics by extending the Metric class and implementing the handle() method.

<?php

namespace App\Metrics;

use Modernmcguire\Overwatch\Metric;

class TotalUsers extends Metric
{
    public function handle()
    {
        return User::count();
    }
}

By default the metric will be snake cased and returned as a string. You can customize this by providing a constant KEY in your metrics.

<?php

namespace App\Metrics;

use Modernmcguire\Overwatch\Metric;

class TotalUsers extends Metric
{
    const KEY = 'app_users';

    public function handle()
    {
        return User::count();
    }
}

Now that you have a new metric to watch, let's add it to your config.

<?php

use App\Metric\TotalUsers;
use Modernmcguire\Overwatch\Metrics\PhpVersion;
use Modernmcguire\Overwatch\Metrics\LaravelVersion;

return [
    'metrics' => [
        PhpVersion::class,
        LaravelVersion::class,

        TotalUsers::class,
    ],
];

Security

In order to protect sensitive metrics, Overwatch requires a secret key to be provided in the request. This secret key is used to encrypt the payload and verify the request came from a trusted source.

To generate a secret key, use the following command:

php artisan overwatch:generate

This will generate a new secret key and store it in your .env file. You can also set the secret key manually by adding the following to your .env file:

OVERWATCH_SECRET=your-secret-key

Fetching Data

To get metric data on an application that has Overwatch installed, you can make a POST request to the /overwatch route. The payload should be encrypted using the secret key that was generated for your application.

<?php

use Illuminate\Encryption\Encrypter;

$newEncrypter = new Encrypter(
    $super_secret_key,
    strtolower(config('app.cipher'))
);

// adding a timestamp to the payload helps prevent replay attacks
$payload = json_encode([
    'timestamp' => now()->toDateTimeString()
]);

$metrics = Http::asJson()->post('https://awesome-application.com/overwatch', [
    'payload' => $newEncrypter->encrypt($payload),
])->json();

Command

You can also retrieve metrics from the command line using the overwatch:metrics command.

php artisan overwatch:metrics

This will return a table response of all the metrics that are defined in your config.

+----------------+---------------------+
| Metric         | Value               |
+----------------+---------------------+
| php_version    | 8.0.3               |
| laravel_version| 8.40.0              |
| app_users      | 10                  |
+----------------+---------------------+

Or you can pass in the --json flag to get a json response.

php artisan overwatch:metrics --json

{"php_version": "8.0.3", "laravel_version": "8.40.0", "app_users": 10}

Testing

vendor/bin/pest

Changelog

Please see CHANGELOG for more information on what has changed recently.

Contributing

Please see CONTRIBUTING for details.

Security Vulnerabilities

Please review our security policy on how to report security vulnerabilities.

Credits

• Modern Mcguire
• All Contributors

License

The MIT License (MIT). Please see License File for more information.