feature request: allow to configure middleware on the handler

[dbu]

In our application, we have some clients where we use specific middleware services. We configure them as symfony service. To allow us to configure them in an eightpoints guzzle client, i found no way to do that and ended up writing a plugin. The plugin is so simple that i think it would make sense to integrate it directly into the bundle to allow a configuration section middleware on each client.

if there is interest, i can do a pull request to integrate middleware configuration. but maybe it is not currently supported on purpose?

The whole code for the plugin is this:

use EightPoints\Bundle\GuzzleBundle\PluginInterface;
use Symfony\Component\Config\Definition\Builder\ArrayNodeDefinition;
use Symfony\Component\DependencyInjection\ContainerBuilder;
use Symfony\Component\DependencyInjection\Definition;
use Symfony\Component\DependencyInjection\Reference;

/**
 * A plugin to allow adding middleware service definitions to clients.
 */
class EightPointsGuzzleMiddlewarePlugin implements PluginInterface
{
    public function getPluginName(): string
    {
        return 'middleware';
    }

    public function addConfiguration(ArrayNodeDefinition $pluginNode): void
    {
        $pluginNode->prototype('scalar');
    }

    public function load(array $configs, ContainerBuilder $container): void
    {
    }

    public function loadForClient(array $config, ContainerBuilder $container, string $clientName, Definition $handler): void
    {
        foreach ($config as $middleware) {
            $handler->addMethodCall('push', [new Reference($middleware)]);
        }
    }

    public function build(ContainerBuilder $container)
    {
    }

    public function boot()
    {
    }
}

and then in the configuration, i can do:

eight_points_guzzle:
    clients:
        my-client:
            base_url: https://example.org
            options:
                connect_timeout: '5'
                headers:
                    Accept: 'application/json'
            plugin:
                middleware:
                    - 'my-custom-guzzle-middleware-service'