TransportConfigForm: Add `instance' form field

refs #9651

modules/monitoring/application/forms/Config/TransportConfigForm.php

@@ -163,6 +163,19 @@ class TransportConfigForm extends ConfigForm
      */
     public function createElements(array $formData)
     {
+        $this->addElement(
+            'text',
+            'instance',
+            array(
+                'placeholder'   => 'default',
+                'label'         => $this->translate('Instance Name'),
+                'description'   => $this->translate(
+                    'The name of the Icinga instance this transport should transfer commands to. You do not '
+                    . 'need to adjust this if you\'re not using a different instance name than the default.'
+                )
+            )
+        );
+
         $this->addElement(
             'text',
             'name',

modules/monitoring/application/forms/Setup/TransportPage.php

@@ -22,6 +22,7 @@ class TransportPage extends Form
         $transportConfigForm = new TransportConfigForm();
         $this->addSubForm($transportConfigForm, 'transport_form');
         $transportConfigForm->create($formData);
+        $transportConfigForm->removeElement('instance');
         $transportConfigForm->getElement('name')->setValue('icinga2');
     }