Added ability to host behind PHP-CGI/FPM

Author: davidcole1340

README.md

@@ -70,8 +70,8 @@ Now that you have registered commands, you can set up an HTTP server to listen f
 
 There are a few ways to set up an HTTP server to listen for requests:
 - The built-in ReactPHP HTTP server.
-- Using an external HTTP server such as Apache or nginx (documentation to come).
-- Using the built-in ReactPHP HTTP server without HTTPS and using Apache or nginx as a reverse proxy.
+- Using an external HTTP server such as Apache or nginx.
+- Using the built-in ReactPHP HTTP server without HTTPS and using Apache or nginx as a reverse proxy (recommended).
 
 Whatever path you choose, the server **must** be protected with HTTPS - Discord will not accept regular HTTP.
 
@@ -157,6 +157,37 @@ $client->registerCommand('my_cool_command', function (Interaction $interaction,
 $discord->run();
 ```
 
+### Running behing PHP-CGI/PHP-FPM
+
+To run behind CGI/FPM and a webserver, the `kambo/httpmessage` package is required:
+
+```sh
+$ composer require kambo/httpmessage
+```
+
+The syntax is then exactly the same as if you were running with the ReactPHP http server, except for the last line:
+
+```php
+<?php
+
+include 'vendor/autoload.php';
+
+use Discord\Slash\Client;
+
+$client = new Client([
+    'public_key' => '???????',
+    'uri' => null, // note the null uri - signifies to not register the socket
+]);
+
+// register your commands like normal
+$client->registerCommand(...);
+
+// note the difference here - runCgi instead of run
+$client->runCgi();
+```
+
+Do note that the regular DiscordPHP client will not run on CGI or FPM, so your mileage may vary.
+
 ### Setting up Apache2 as a reverse proxy
 
 Assuming you already have Apache2 installed and the SSL certificates on your server:

composer.json

@@ -24,5 +24,8 @@
     },
     "require-dev": {
         "symfony/var-dumper": "^5.2"
+    },
+    "suggest": {
+        "kambo/httpmessage": "Required for hosting the command server behind a CGI/FPM server."
     }
 }

src/Discord/Client.php

@@ -7,8 +7,11 @@
 use Discord\InteractionType;
 use Discord\Slash\Parts\Interaction;
 use Discord\Slash\Parts\RegisteredCommand;
+use Exception;
 use InvalidArgumentException;
-use React\Http\MEssage\Response;
+use Kambo\Http\Message\Environment\Environment;
+use Kambo\Http\Message\Factories\Environment\ServerRequestFactory;
+use React\Http\Message\Response;
 use Monolog\Handler\StreamHandler;
 use Monolog\Logger;
 use Psr\Http\Message\ServerRequestInterface;
@@ -116,14 +119,14 @@ private function resolveOptions(array $options): array
      */
     private function registerServer()
     {
+        // no uri => cgi/fpm
+        if (is_null($this->options['uri'])) {
+            return;
+        }
+
         $this->server = new HttpServer($this->getLoop(), [$this, 'handleRequest']);
         $this->socket = new SocketServer($this->options['uri'], $this->getLoop(), $this->options['socket_options']);
-
-        // future tick so that the socket won't listen
-        // when running in CGI mode
-        $this->getLoop()->futureTick(function () {
-            $this->server->listen($this->socket);
-        });
+        $this->server->listen($this->socket);
     }
 
     /**
@@ -138,7 +141,7 @@ public function handleRequest(ServerRequestInterface $request)
         $timestamp = $request->getHeaderLine('X-Signature-Timestamp');
 
         if (empty($signature) || empty($timestamp) || ! DiscordInteraction::verifyKey((string) $request->getBody(), $signature, $timestamp, $this->options['public_key'])) {
-            return new Response(401, [0], 'Not verified');
+            return \React\Promise\Resolve(new Response(401, [0], 'Not verified'));
         }
 
         $interaction = new Interaction(json_decode($request->getBody(), true));
@@ -182,7 +185,7 @@ private function handleApplicationCommand(Interaction $interaction): void
     {
         $checkCommand = function ($command) use ($interaction, &$checkCommand) {
             if (isset($this->commands[$command['name']])) {
-                if ($this->commands[$command['name']]->execute($command['options'], $interaction)) return true;
+                if ($this->commands[$command['name']]->execute($command['options'] ?? [], $interaction)) return true;
             }
 
             foreach ($command['options'] ?? [] as $option) {
@@ -221,6 +224,28 @@ public function registerCommand($name, callable $callback = null): RegisteredCom
         return $this->commands[$baseCommand]->addSubCommand($name, $callback);
     }
 
+    /**
+     * Runs the client on a CGI/FPM server.
+     */
+    public function runCgi()
+    {
+        if (empty($_SERVER['REMOTE_ADDR'])) {
+            throw new Exception('The `runCgi()` method must only be called from PHP-CGI/FPM.');
+        }
+        
+        if (! class_exists(Environment::class)) {
+            throw new Exception('The `kambo/httpmessage` package must be installed to handle slash command interactions with a CGI/FPM server.');
+        }
+
+        $environment = new Environment($_SERVER, fopen('php://input', 'w+'), $_POST, $_COOKIE, $_FILES);
+        $serverRequest = (new ServerRequestFactory())->create($environment);
+    
+        $this->handleRequest($serverRequest)->then(function (Response $response) {
+            http_response_code($response->getStatusCode());
+            echo (string) $response->getBody();
+        });
+    }
+
     /**
      * Starts the ReactPHP event loop.
      */