Laravel Authentication Proxy Controller for CouchDB/PouchDB Syncing

api.php

<?php

use Illuminate\Http\Request;
use Illuminate\Support\Facades\Auth;

/*
|--------------------------------------------------------------------------
| API Routes
|--------------------------------------------------------------------------
|
| Here is where you can register API routes for your application. These
| routes are loaded by the RouteServiceProvider within a group which
| is assigned the "api" middleware group. Enjoy building your API!
|
*/

Route::group(['middleware' => 'auth:api'], function($router) {
	Route::any('/sync/{path?}', 'SyncController')->where(['path' => '.*']);
});

SyncController.php

<?php
//
//	SyncController
//
//	A controller for Laravel authentication when performing CouchDB syncing.
//
//	This controller assumes a user per database approach and that when a user registers with the Laravel 
//	web app a couchdb_username is generated and stored in the user record. This name is used for the 
//	creation of a corresponding couchdb user and database.
//
//	To use set up the appropriate routes (shown in api.php below) and have the client (e.g. PouchDB) sync 
//	to a url like https://example.app/api/sync/db/<database_name>.
//
//	Dependent packages - "jenssegers/proxy": "v3.0.0-beta2"
//

namespace App\Http\Controllers;

use App\User;
use Illuminate\Support\Facades\Auth;
use App\Http\Controllers\Controller;
use Proxy\Proxy;
use Proxy\Adapter\Guzzle\GuzzleAdapter;
use Zend\Diactoros\ServerRequestFactory;

class SyncController extends Controller
{
    public function __invoke($path = null)
    {
	    $couchUrl = env('COUCHDB_URL', 'http://localhost:5984/');
		$user_pass = '';

		if($path === null)	// i.e. not trying to hit a database
		{
			$_SERVER['REQUEST_URI'] = str_replace("api/sync/", "", $_SERVER['REQUEST_URI']);
		}
		else
		{
			$user = Auth::user();

			$couchSecret = env('COUCHDB_SECRET');
			$username = $user->couch_username;
			$password = hash_hmac('sha256', $username, $couchSecret);
			$user_pass = $username . ':' . $password;

			// Edit the request uri for couchdb and user database
			// The /db is required as pouchdb tries to hit api/sync to check if couch is around (the db is acting as a dummy database name)
			$_SERVER['REQUEST_URI'] = '/' . $username . str_replace("api/sync/db/", "", $_SERVER['REQUEST_URI']);
		}

		$request = ServerRequestFactory::fromGlobals();

		// Set Authorisation headers
		$request = $request->withHeader('Authorization', 'Basic ' . base64_encode($user_pass));

		// Create a guzzle client
		$guzzle = new \GuzzleHttp\Client();

		// Create the proxy instance
		$proxy = new Proxy(new GuzzleAdapter($guzzle));

		try
		{
			// Forward the request and get the response.
			$response = $proxy->forward($request)->to($couchUrl);

			// Output response to the client.
			return response($response->getBody(), $response->getStatusCode());
		}
		catch (\GuzzleHttp\Exception\ClientException $e)
		{
			$status = $e->getResponse()->getStatusCode();

		    return response($e->getResponse()->getBody(true), $status);
		}
    }
}