IcingaCommand: do not allow to delete while in use

fixes #1443

doc/82-Changelog.md

@@ -24,6 +24,7 @@ before switching to a new version.
 * FEATURE: A Service Set can now be assigned to multiple hosts at once #1281
 * FEATURE: Commands can now be filtered by usage (#1480)
 * FIX: Don't suggest Command templates where Commands are required (#1414)
+* FIX: Do not allow to delete Commands being used by other objects (#1443)
 
 ### CLI
 * FEATURE: Director Health Check Plugin (#1278)

library/Director/Objects/IcingaCommand.php

@@ -5,6 +5,7 @@ namespace Icinga\Module\Director\Objects;
 use Icinga\Module\Director\IcingaConfig\IcingaConfigHelper as c;
 use Icinga\Module\Director\IcingaConfig\IcingaLegacyConfigHelper as c1;
 use Icinga\Module\Director\Objects\Extension\Arguments;
+use Zend_Db_Select as DbSelect;
 
 class IcingaCommand extends IcingaObject implements ObjectWithArguments
 {
@@ -149,6 +150,41 @@ class IcingaCommand extends IcingaObject implements ObjectWithArguments
         return true;
     }
 
+    public function countDirectUses()
+    {
+        $db = $this->getDb();
+        $id = (int) $this->get('id');
+
+        $qh = $db->select()->from(
+            array('h' => 'icinga_host'),
+            array('cnt' => 'COUNT(*)')
+        )->where('h.check_command_id = ?', $id)
+         ->orWhere('h.event_command_id = ?', $id);
+        $qs = $db->select()->from(
+            array('s' => 'icinga_service'),
+            array('cnt' => 'COUNT(*)')
+        )->where('s.check_command_id = ?', $id)
+            ->orWhere('s.event_command_id = ?', $id);
+        $qn = $db->select()->from(
+            array('n' => 'icinga_notification'),
+            array('cnt' => 'COUNT(*)')
+        )->where('n.command_id = ?', $id);
+        $query = $db->select()->union(
+            [$qh, $qs, $qn],
+            DbSelect::SQL_UNION_ALL
+        );
+
+        return $db->fetchOne($db->select()->from(
+            ['all_cnts' => $query],
+            ['cnt' => 'SUM(cnt)']
+        ));
+    }
+
+    public function isInUse()
+    {
+        return $this->countDirectUses() > 0;
+    }
+
     protected function renderCommand()
     {
         $command = $this->command;

library/Director/Web/Form/DirectorObjectForm.php

@@ -11,6 +11,7 @@ use Icinga\Module\Director\Exception\NestingError;
 use Icinga\Module\Director\IcingaConfig\StateFilterSet;
 use Icinga\Module\Director\IcingaConfig\TypeFilterSet;
 use Icinga\Module\Director\Objects\IcingaTemplateChoice;
+use Icinga\Module\Director\Objects\IcingaCommand;
 use Icinga\Module\Director\Objects\IcingaObject;
 use Icinga\Module\Director\Util;
 use Icinga\Module\Director\Web\Form\Validate\NamePattern;
@@ -885,6 +886,15 @@ abstract class DirectorObjectForm extends DirectorForm
                     )
                 );
             }
+        } elseif ($object instanceof IcingaCommand && $object->isInUse()) {
+            $el->setAttrib('disabled', 'disabled');
+            $el->setAttrib(
+                'title',
+                sprintf(
+                    $this->translate('This Command is still in use by %d other objects'),
+                    $object->countDirectUses()
+                )
+            );
         }
 
         $this->addElement($el);