RequestHandler: optionally return stack traces

fixes #2570

doc/70-REST-API.md

@@ -123,6 +123,7 @@ Icinga Objects
 | withServices   | Show services attached to a host. `resolved` and `withNull` |
 |                | are applied for services too                                |
 | allowOverrides | Set variable overrides for virtual Services                 |
+| showStacktrace | Returns the related stack trace, in case an error occurs    |
 
 #### Resolve object properties
 

doc/82-Changelog.md

@@ -23,6 +23,7 @@ v1.10.0 (unreleased)
 
 ### REST API
 * FIX: addressing service templates by name has been fixed (#2487)
+* FEATURE: Stack traces can now be requested (#2570)
 
 ### CLI
 * FIX: config deploy doesn't try to wait in case of no deployment (#2522)

library/Director/RestApi/RequestHandler.php

@@ -58,7 +58,11 @@ abstract class RequestHandler
         }
 
         $response->sendHeaders();
-        $this->sendJson((object) ['error' => $message]);
+        $result = ['error' => $message];
+        if ($this->request->getUrl()->getParam('showStacktrace')) {
+            $result['trace'] = $error->getTraceAsString();
+        }
+        $this->sendJson((object) $result);
     }
 
     // TODO: just return json_last_error_msg() for PHP >= 5.5.0