Merge branch 'zacksleo-feature-on-one-server'

README.md

@@ -29,8 +29,8 @@ This project is inspired by the Laravel's Schedule component and tries to bring
 Quote from Laravel's documentation:
 
 ```
-In the past, developers have generated a Cron entry for each console command they wished to schedule. 
-However, this is a headache. Your console schedule is no longer in source control, 
+In the past, developers have generated a Cron entry for each console command they wished to schedule.
+However, this is a headache. Your console schedule is no longer in source control,
 and you must SSH into your server to add the Cron entries. Let's make our lives easier.
 ```
 
@@ -153,6 +153,32 @@ $schedule->command('foo')->withoutOverlapping();
 ```
 Used by default yii\mutex\FileMutex or 'mutex' application component (http://www.yiiframework.com/doc-2.0/yii-mutex-mutex.html)
 
+**Running Tasks On One Server**
+
+>To utilize this feature, you must config mutex in the application component, except the FileMutex:  `yii\mutex\MysqlMutex`,`yii\mutex\PgsqlMutex`,`yii\mutex\OracleMutex` or `yii\redis\Mutex`. In addition, all servers must be communicating with the same central db/cache server.
+
+Below shows the redis mutex demo:
+
+```php
+'components' => [
+    'mutex' => [
+        'class' => 'yii\redis\Mutex',
+        'redis' => [
+            'hostname' => 'localhost',
+            'port' => 6379,
+            'database' => 0,
+        ]
+    ],
+],
+```
+
+```php
+$schedule->command('report:generate')
+                ->fridays()
+                ->at('17:00')
+                ->onOneServer();
+```
+
 How to use this extension in your application?
 ----------------------------------------------
 

src/Event.php

@@ -8,9 +8,10 @@
 use yii\base\Application;
 use yii\base\Component;
 use yii\base\InvalidCallException;
+use yii\base\InvalidConfigException;
 use yii\mail\MailerInterface;
 use yii\mutex\Mutex;
-
+use yii\mutex\FileMutex;
 
 /**
  * Class Event
@@ -518,6 +519,20 @@ public function withoutOverlapping()
         });
     }
 
+    /**
+     * Allow the event to only run on one server for each cron expression.
+     *
+     * @return $this
+     */
+    public function onOneServer()
+    {
+        if ($this->_mutex instanceof FileMutex) {
+            throw new InvalidConfigException('You must config mutex in the application component, except the FileMutex.');
+        }
+
+        return $this->withoutOverlapping();
+    }
+
     /**
      * Register a callback to further filter the schedule.
      *