Run the sitemap_generate cron job correctly

Author: James Halsall

app/code/Magento/Sitemap/Model/Observer.php

@@ -20,7 +20,7 @@ class Observer
     /**
      * Cronjob expression configuration
      */
-    const XML_PATH_CRON_EXPR = 'crontab/default/jobs/generate_sitemaps/schedule/cron_expr';
+    const XML_PATH_CRON_EXPR = 'crontab/default/jobs/sitemap_generate/schedule/cron_expr';
 
     /**
      * Error email template configuration
@@ -64,25 +64,33 @@ class Observer
      */
     protected $inlineTranslation;
 
+    /**
+     * @var \Magento\Cron\Model\ScheduleFactory
+     */
+    private $scheduleFactory;
+
     /**
      * @param \Magento\Framework\App\Config\ScopeConfigInterface $scopeConfig
      * @param \Magento\Sitemap\Model\ResourceModel\Sitemap\CollectionFactory $collectionFactory
      * @param \Magento\Store\Model\StoreManagerInterface $storeManager
      * @param \Magento\Framework\Mail\Template\TransportBuilder $transportBuilder
      * @param \Magento\Framework\Translate\Inline\StateInterface $inlineTranslation
+     * @param \Magento\Cron\Model\ScheduleFactory $scheduleFactory
      */
     public function __construct(
         \Magento\Framework\App\Config\ScopeConfigInterface $scopeConfig,
         \Magento\Sitemap\Model\ResourceModel\Sitemap\CollectionFactory $collectionFactory,
         \Magento\Store\Model\StoreManagerInterface $storeManager,
         \Magento\Framework\Mail\Template\TransportBuilder $transportBuilder,
-        \Magento\Framework\Translate\Inline\StateInterface $inlineTranslation
+        \Magento\Framework\Translate\Inline\StateInterface $inlineTranslation,
+        \Magento\Cron\Model\ScheduleFactory $scheduleFactory
     ) {
         $this->_scopeConfig = $scopeConfig;
         $this->_collectionFactory = $collectionFactory;
         $this->_storeManager = $storeManager;
         $this->_transportBuilder = $transportBuilder;
         $this->inlineTranslation = $inlineTranslation;
+        $this->scheduleFactory = $scheduleFactory;
     }
 
     /**
@@ -105,6 +113,14 @@ public function scheduledGenerateSitemaps()
             return;
         }
 
+        $schedule = $this->scheduleFactory->create();
+        $schedule->setScheduledAt(date('Y-m-d H:i:s'));
+        $schedule->setCronExpr($this->_scopeConfig->getValue(self::XML_PATH_CRON_EXPR));
+
+        if (!$schedule->trySchedule()) {
+            return;
+        }
+
         $collection = $this->_collectionFactory->create();
         /* @var $collection \Magento\Sitemap\Model\ResourceModel\Sitemap\Collection */
         foreach ($collection as $sitemap) {

app/code/Magento/Sitemap/etc/crontab.xml

@@ -7,6 +7,8 @@
 -->
 <config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Cron:etc/crontab.xsd">
     <group id="default">
-        <job name="sitemap_generate" instance="Magento\Sitemap\Model\Observer" method="scheduledGenerateSitemaps" />
+        <job name="sitemap_generate" instance="Magento\Sitemap\Model\Observer" method="scheduledGenerateSitemaps">
+            <schedule>* * * * *</schedule>
+        </job>
     </group>
 </config>