SyncruleCommand: show number of expected changes

Sample output when there are changes:

    icingaweb2@web:~$ icingacli director syncrule check --id 36
    There are pending changes for this Sync Rule. You should  trigger a new Sync Run.
    Expected modifications: 2x create, 0x modify, 0x delete
    icingaweb2@web:~$ echo $?
    1

...when there are no changes:

    icingaweb2@web:~$ icingacli director syncrule check --id 34
    This Sync Rule is in sync
    icingaweb2@web:~$ echo $?
    0

...and when something failes:

    icingaweb2@web:~$ icingacli director syncrule check --id 32
    This Sync Rule failed: No data has been imported for "Benutzergruppen aus Nagios" yet
    icingaweb2@web:~$ echo $?
    2

fixes #1849

application/clicommands/SyncruleCommand.php

@@ -3,7 +3,9 @@
 namespace Icinga\Module\Director\Clicommands;
 
 use Icinga\Module\Director\Cli\Command;
+use Icinga\Module\Director\Objects\IcingaObject;
 use Icinga\Module\Director\Objects\SyncRule;
+use RuntimeException;
 
 /**
  * Deal with Director Sync Rules
@@ -59,8 +61,47 @@ class SyncruleCommand extends Command
     public function checkAction()
     {
         $rule = $this->getSyncRule();
-        $rule->checkForChanges();
+        $hasChanges = $rule->checkForChanges();
         $this->showSyncStateDetails($rule);
+        if ($hasChanges) {
+            $mods = $this->getExpectedModificationCounts($rule);
+            printf(
+                "Expected modifications: %dx create, %dx modify, %dx delete\n",
+                $mods->modify,
+                $mods->create,
+                $mods->delete
+            );
+        }
+
+        exit($this->getSyncStateExitCode($rule));
+    }
+
+    protected function getExpectedModificationCounts(SyncRule $rule)
+    {
+        $modifications = $rule->getExpectedModifications();
+
+        $create = 0;
+        $modify = 0;
+        $delete = 0;
+
+        /** @var IcingaObject $object */
+        foreach ($modifications as $object) {
+            if ($object->hasBeenLoadedFromDb()) {
+                if ($object->shouldBeRemoved()) {
+                    $delete++;
+                } else {
+                    $modify++;
+                }
+            } else {
+                $create++;
+            }
+        }
+
+        return (object) [
+            'create' => $create,
+            'modify' => $modify,
+            'delete' => $delete,
+        ];
     }
 
     /**
@@ -103,7 +144,6 @@ class SyncruleCommand extends Command
 
     /**
      * @param SyncRule $rule
-     * @throws \Icinga\Exception\IcingaException
      */
     protected function showSyncStateDetails(SyncRule $rule)
     {
@@ -113,7 +153,6 @@ class SyncruleCommand extends Command
     /**
      * @param SyncRule $rule
      * @return string
-     * @throws \Icinga\Exception\IcingaException
      */
     protected function getSyncStateDescription(SyncRule $rule)
     {
@@ -128,6 +167,28 @@ class SyncruleCommand extends Command
                     . '  trigger a new Sync Run.';
             case 'failing':
                 return 'This Sync Rule failed: '. $rule->get('last_error_message');
+            default:
+                throw new RuntimeException('Invalid sync state: ' . $rule->get('sync_state'));
+        }
+    }
+
+    /**
+     * @param SyncRule $rule
+     * @return string
+     */
+    protected function getSyncStateExitCode(SyncRule $rule)
+    {
+        switch ($rule->get('sync_state')) {
+            case 'unknown':
+                return 3;
+            case 'in-sync':
+                return 0;
+            case 'pending-changes':
+                return 1;
+            case 'failing':
+                return 2;
+            default:
+                throw new RuntimeException('Invalid sync state: ' . $rule->get('sync_state'));
         }
     }
 }

library/Director/Objects/SyncRule.php

@@ -4,6 +4,7 @@ namespace Icinga\Module\Director\Objects;
 
 use Icinga\Application\Benchmark;
 use Icinga\Data\Filter\Filter;
+use Icinga\Exception\IcingaException;
 use Icinga\Module\Director\Data\Db\DbObject;
 use Icinga\Module\Director\Db;
 use Icinga\Module\Director\DirectorObject\Automation\ExportInterface;
@@ -184,7 +185,7 @@ class SyncRule extends DbObject implements ExportInterface
 
     /**
      * @return IcingaObject[]
-     * @throws Exception
+     * @throws IcingaException
      */
     public function getExpectedModifications()
     {