Slim Middleware bundle

A Slim 4 Framework useful middlewares.

Features

• health check endpoint;
• info endpoint;
• settings setup;
• exception handler;
• APISIX auto route register;
• Leader election middleware;
• Endpoint protection with X-Api-Token.

Table of contents

• Install
• [Health check endpoint usage](#health check endpoint usage)
• [Info endpoint usage](#info endpoint usage)
• [Settings setup usage](#settings setup usage)
• [Exception handler usage](#exception handler usage)
• [APISIX auto route register usage](#apisix auto route register usage)
• [Leader election usage](#leader election usage)
• [Endpoint protection with X-Api-Token usage](#endpoint protection with X-Api-Token usage)

Install

Via Composer

$ composer require benycode/slim-middleware

Requires Slim 4.

Health check endpoint usage

Use DI to inject the library Middleware classes:

use BenyCode\Slim\Middleware\HealthCheckEndpointMiddleware;

return [
    ......
    HealthCheckEndpointMiddleware::class => function (ContainerInterface $container) {
        return new HealthCheckEndpointMiddleware(
           [
              'health_endpoint' => '/_health', // change if needed other endpoint
           ],
           <<inject you PSR7 logger if needed>>,
        );
    },
    ......
];

add the Middleware to any route at the end of the routes:

use Slim\Exception\HttpNotFoundException;
use BenyCode\Slim\Middleware\HealthCheckEndpointMiddleware;

$app
   ->get(
   '/{any:.*}',
   function (Request $request, Response $response) {
      throw new HttpNotFoundException($request);
   }
   )
   ....
   ->add(HealthCheckEndpointMiddleware::class)
   ->setName('any')
   ;

welcome, your app is within new path:

• /_health or your defined

create health check.

Info endpoint usage

Use DI to inject the library Middleware classes:

use BenyCode\Slim\Middleware\InfoEndpointMiddleware;

return [
    ......
    InfoEndpointMiddleware::class => function (ContainerInterface $container) {
        return new InfoEndpointMiddleware(
           [
              'info_endpoint' => '/_info', // change if needed other endpoint
           ],
           '<<define api version here>>', // example: v0.0.0
        );
    },
    ......
];

add the Middleware to any route at the end of the routes:

use Slim\Exception\HttpNotFoundException;
use BenyCode\Slim\Middleware\InfoEndpointMiddleware;

$app
   ->get(
   '/{any:.*}',
   function (Request $request, Response $response) {
      throw new HttpNotFoundException($request);
   }
   )
   ....
   ->add(InfoEndpointMiddleware::class)
   ->setName('any')
   ;

welcome, your app is within new path:

• /_info

Settings setup usage

add the Middleware to a global list:

use BenyCode\Middleware\SettingsUpMiddleware;

return function (App $app) {
        ...
        $app->add(SettingsUpMiddleware::class);
        ...
};

get the settings:

protected function __invoke(ServerRequestInterface $request, ResponseInterface $response): ResponseInterface {
   $settings = $request
      ->getAttribute('settings')
   ;
}

Exception handler usage

add the Middleware to a global list:

use BenyCode\Middleware\ExceptionMiddleware;

return function (App $app) {
        ...
        $app->add(ExceptionMiddleware::class);
        ...
};

welcome, your app is within new error handler.

APISIX auto route register usage

Idea: Auto create service and routes on the health check procedure.

You can use it with:

• Docker health check;
• k8s health check;
• and more others....

Requires curl and docker/k8s health check mechanism.

Balanced with LeaderElectionMiddleware, bring more stability and activate one instance registration functionality.

Use DI to inject the library Middleware classes:

use BenyCode\Slim\Middleware\APISIXRegisterMiddleware;

return [
    ......
    APISIXRegisterMiddleware::class => function (ContainerInterface $container) {
       return new APISIXRegisterMiddleware(
       [
          'register_endpoint' => '/_health', // change if needed other endpoint
          'service_id' => '<<describe your service name>>',
          'service' => [
             'upstream' => [
                'type' => 'roundrobin',
                'nodes' => [
                   '<<describe working endpoint>>:<<describe working port>>' => 1, // example: books-microservice:80
                ],
             ],
          ],
          'route' => [
             'uri' => "<<describe working path>>", // example: /books/*
             'service_id' => '<<describe service id>>', // example: books-microservice
          ],
          'api_admin_secret' => '<<describe APISIX admin secret>>',
          'api_endpoint' => '<<describe APISIX API endpoint url>>', // example: http://api-gateway:9180
        ],
	<<inject you PSR7 logger if needed>>,
        );
    },
    ......
];

add the Middleware to any route at the end of the routes:

use Slim\Exception\HttpNotFoundException;
use BenyCode\Slim\Middleware\APISIXRegisterMiddleware;

$app
   ->get(
   '/{any:.*}',
   function (Request $request, Response $response) {
      throw new HttpNotFoundException($request);
   }
   )
   ....
   ->add(APISIXRegisterMiddleware::class)
   ->setName('any')
   ;

create health check /_health or your defined.

welcome, your app will be auto (re)registered in the APISIX on the every health check.

Leader election usage

Idea: in the microservice world can be more then one instance who can execute the relevant commands and there is a need for those commands to be executed only by one. Vote for the leader using health check mechanizm!

Balanced with the APISIXRegisterMiddleware.

You can use it with:

• Docker health check;
• k8s health check;
• and more others....

Requires curl, docker/k8s health check mechanism and ETCD v3.

Use DI to inject the library Middleware classes:

use BenyCode\Slim\Middleware\LeaderElectionMiddleware;

return [
    ......
    LeaderElectionMiddleware::class => function (ContainerInterface $container) {
       return new LeaderElectionMiddleware(
          [
             'leader_election_endpoint' => '/_health', // change if needed other endpoint
             'etcd_endpoint' => '<<etcd endpoint>>',
             'alection_frequency' => 5, // alection frequence in seconds
              <<inject you PSR7 logger if needed>>,
          ],
        );
    },
    ......
];

add the Middleware to any route at the end of the routes:

use Slim\Exception\HttpNotFoundException;
use BenyCode\Slim\Middleware\LeaderElectionMiddleware;

$app
   ->get(
   '/{any:.*}',
   function (Request $request, Response $response) {
      throw new HttpNotFoundException($request);
   }
   )
   ....
   ->add(LeaderElectionMiddleware::class)
   ->setName('any')
   ;

get the leader status:

protected function __invoke(ServerRequestInterface $request, ResponseInterface $response): ResponseInterface {
   $leader = $request
      ->getAttribute('im_leader')
   ;

   if($leader) {
      // the leader code
   }
}

Endpoint protection with X-Api-Token usage

Idea: Protect you endpoints like health check with Api token.

Use DI to inject the library Middleware classes:

use BenyCode\Slim\Middleware\OnePathXApiTokenProtectionMiddleware;

return [
    ......
    OnePathXApiTokenProtectionMiddleware::class => function (ContainerInterface $container) {
       return new OnePathXApiTokenProtectionMiddleware(
          [
             'path' => '/_health', // change if needed other endpoint
             'x-api-token' => '4bfdb81c03f42600d9018103a4df878b', // change to yours
              <<inject you PSR7 logger if needed>>,
          ],
        );
    },
    ......
];

add the Middleware to any route at the end of the routes:

use Slim\Exception\HttpNotFoundException;
use BenyCode\Slim\Middleware\OnePathXApiTokenProtectionMiddleware;

$app
   ->get(
   '/{any:.*}',
   function (Request $request, Response $response) {
      throw new HttpNotFoundException($request);
   }
   )
   ....
   ->add(OnePathXApiTokenProtectionMiddleware::class)
   ->setName('any')
   ;