Use a default generated handler URL

Author: marickvantuil

README.md

@@ -78,13 +78,13 @@ Now that the package is installed, the final step is to set the correct environm
 
 Please check the table below on what the values mean and what their value should be.
 
-|Environment variable| Description                                                                                                                                                               |Example
-  |---|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---
-|`STACKKIT_CLOUD_TASKS_PROJECT`| The project your queue belongs to.                                                                                                                                        |`my-project`
-|`STACKKIT_CLOUD_TASKS_LOCATION`| The region where the AppEngine is hosted                                                                                                                                  |`europe-west6`
-|`STACKKIT_CLOUD_TASKS_HANDLER`| The URL that Cloud Tasks will call to process a job. This should be the URL to your Laravel app with the `handle-task` path added                                         |`https://<your website>.com/handle-task`
-|`STACKKIT_CLOUD_TASKS_QUEUE`| The queue a job will be added to                                                                                                                                          |`emails`
-|`STACKKIT_CLOUD_TASKS_SERVICE_EMAIL`| The email address of the AppEngine service account. Important, it should have the correct roles. See the section below which roles. |`[email protected].com`
+| Environment variable                 | Description                                                                                                                                                                                |Example
+--------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---
+| `STACKKIT_CLOUD_TASKS_PROJECT`       | The project your queue belongs to.                                                                                                                                                         |`my-project`
+| `STACKKIT_CLOUD_TASKS_LOCATION`      | The region where the AppEngine is hosted                                                                                                                                                   |`europe-west6`
+| `STACKKIT_CLOUD_TASKS_QUEUE`         | The queue a job will be added to                                                                                                                                                           |`emails`
+| `STACKKIT_CLOUD_TASKS_SERVICE_EMAIL` | The email address of the AppEngine service account. Important, it should have the correct roles. See the section below which roles.                                                        |`[email protected]`
+| `STACKKIT_CLOUD_TASKS_HANDLER` (optional) | The URL that Cloud Tasks will call to process a job. This should be the URL to your Laravel app with the `handle-task` path added. By default we will use the URL that dispatched the job. |`https://<your website>.com/handle-task`
 </details>
 <details>
 <summary>

src/CloudTasksConnector.php

@@ -11,6 +11,18 @@ public function connect(array $config)
     {
         Config::validate($config);
 
+        // The handler is the URL which Cloud Tasks will call with the job payload. This
+        // URL of the handler can be manually set through an environment variable, but
+        // if it is not then we will choose a sensible default (the current app url)
+        if (empty($config['handler'])) {
+            // At this point (during service provider boot) the trusted proxy middleware
+            // has not been set up, and so we are not ready to get the scheme and host
+            // So we wrap it and get it later, after the middleware has been set up.
+            $config['handler'] = function () {
+                return request()->getSchemeAndHttpHost();
+            };
+        }
+
         return new CloudTasksQueue($config, app(CloudTasksClient::class));
     }
 }

src/CloudTasksQueue.php

@@ -100,7 +100,7 @@ protected function pushToCloudTasks($queue, $payload, $delay = 0)
         $availableAt = $this->availableAt($delay);
 
         $httpRequest = $this->createHttpRequest();
-        $httpRequest->setUrl($this->config['handler']);
+        $httpRequest->setUrl(Config::getHandler($this->config['handler']));
         $httpRequest->setHttpMethod(HttpMethod::POST);
         $httpRequest->setBody(
             // Laravel 7+ jobs have a uuid, but Laravel 6 doesn't have it.

src/CloudTasksServiceProvider.php

@@ -7,23 +7,21 @@
 use Illuminate\Queue\Events\JobFailed;
 use Illuminate\Queue\Events\JobProcessed;
 use Illuminate\Queue\Events\JobProcessing;
-use Illuminate\Queue\QueueManager;
-use Illuminate\Routing\Router;
 use Illuminate\Support\ServiceProvider as LaravelServiceProvider;
 use function Safe\file_get_contents;
 use function Safe\json_decode;
 
 class CloudTasksServiceProvider extends LaravelServiceProvider
 {
-    public function boot(QueueManager $queue, Router $router): void
+    public function boot(): void
     {
         $this->registerClient();
-        $this->registerConnector($queue);
+        $this->registerConnector();
         $this->registerConfig();
         $this->registerViews();
         $this->registerAssets();
         $this->registerMigrations();
-        $this->registerRoutes($router);
+        $this->registerRoutes();
         $this->registerDashboard();
     }
 
@@ -37,8 +35,13 @@ private function registerClient(): void
         $this->app->bind('cloud-tasks-api', CloudTasksApiConcrete::class);
     }
 
-    private function registerConnector(QueueManager $queue): void
+    private function registerConnector(): void
     {
+        /**
+         * @var \Illuminate\Queue\QueueManager $queue
+         */
+        $queue = $this->app['queue'];
+
         $queue->addConnector('cloudtasks', function () {
             return new CloudTasksConnector;
         });
@@ -85,8 +88,13 @@ private function registerMigrations(): void
         ]);
     }
 
-    private function registerRoutes(Router $router): void
+    private function registerRoutes(): void
     {
+        /**
+         * @var \Illuminate\Routing\Router $router
+         */
+        $router = $this->app['router'];
+
         $router->post('handle-task', [TaskHandler::class, 'handle'])->name('cloud-tasks.handle-task');
 
         if (CloudTasks::dashboardDisabled()) {

src/Config.php

@@ -2,7 +2,10 @@
 
 namespace Stackkit\LaravelGoogleCloudTasksQueue;
 
+use Closure;
 use Error;
+use Exception;
+use Safe\Exceptions\UrlException;
 
 class Config
 {
@@ -16,12 +19,55 @@ public static function validate(array $config): void
             throw new Error(Errors::invalidLocation());
         }
 
-        if (empty($config['handler'])) {
-            throw new Error(Errors::invalidHandler());
-        }
-
         if (empty($config['service_account_email'])) {
             throw new Error(Errors::invalidServiceAccountEmail());
         }
     }
+
+    /**
+     * @param Closure|string $handler
+     */
+    public static function getHandler($handler): string
+    {
+        $handler = value($handler);
+
+        try {
+            $parse = \Safe\parse_url($handler);
+
+            if (empty($parse['host'])) {
+                throw new UrlException();
+            }
+
+            // A mistake which can unknowingly be made is that the task handler URL is
+            // (still) set to localhost. That will never work because Cloud Tasks
+            // should always call a public address / hostname to process tasks.
+            if (in_array($parse['host'], ['localhost', '127.0.0.1', '::1'])) {
+                throw new Exception(sprintf(
+                    'Unable to push task to Cloud Tasks because the handler URL is set to a local host: %s. ' .
+                    'This does not work because Google is not able to call the given local URL. ' .
+                    'If you are developing on locally, consider using Ngrok or Expose for Laravel to expose your local ' .
+                    'application to the internet.',
+                    $handler
+                ));
+            }
+
+            // Versions 1.x and 2.x required the full path (e.g. my-app.com/handle-task). In 3.x and beyond
+            // it is no longer necessary to also include the path and simply setting the handler
+            // URL is enough. If someone upgrades and forgets we will warn them here.
+            if (!empty($parse['path'])) {
+                throw new Exception(
+                    'Unable to push task to Cloud Tasks because the task handler URL (' . $handler . ') is not ' .
+                    'compatible. To fix this, please remove \'' . $parse['path'] . '\' from the URL, ' .
+                    'or copy from here: STACKKIT_CLOUD_TASKS_HANDLER=' . $parse['scheme'] . '://' . $parse['host']
+                );
+            }
+
+            return $handler . '/handle-task';
+        } catch (UrlException $e) {
+            throw new Exception(
+                'Unable to push task to Cloud Tasks because the task handler URL (' . $handler . ') is ' .
+                'malformed. Please inspect the URL closely for any mistakes.'
+            );
+        }
+    }
 }

src/Errors.php

@@ -14,11 +14,6 @@ public static function invalidLocation(): string
         return 'Google Cloud Tasks location not provided. To fix this, set the STACKKIT_CLOUD_TASKS_LOCATION environment variable';
     }
 
-    public static function invalidHandler(): string
-    {
-        return 'Google Cloud Tasks handler not provided. To fix this, set the STACKKIT_CLOUD_TASKS_HANDLER environment variable';
-    }
-
     public static function invalidServiceAccountEmail(): string
     {
         return 'Google Service Account email address not provided. This is needed to secure the handler so it is only accessible by Google. To fix this, set the STACKKIT_CLOUD_TASKS_SERVICE_EMAIL environment variable';

src/TaskHandler.php

@@ -57,7 +57,7 @@ private function loadQueueConnectionConfiguration(array $task): void
          * @var stdClass $command
          */
         $command = unserialize($task['data']['command']);
-        $connection = $command->command ?? config('queue.default');
+        $connection = $command->connection ?? config('queue.default');
         $this->config = array_merge(
             (array) config("queue.connections.{$connection}"),
             ['connection' => $connection]

tests/ConfigTest.php

@@ -31,7 +31,7 @@ public function location_is_required()
     }
 
     /** @test */
-    public function handler_is_required()
+    public function there_is_a_sensible_handler_default()
     {
         $this->setConfigValue('handler', '');