Add interface for installers

refs #7163

library/Icinga/Web/Setup/Installer.php

@@ -0,0 +1,32 @@
+<?php
+// {{{ICINGA_LICENSE_HEADER}}}
+// {{{ICINGA_LICENSE_HEADER}}}
+
+namespace Icinga\Web\Setup;
+
+/**
+ * Interface for installers providing a summary and action report
+ */
+interface Installer
+{
+    /**
+     * Run the installation and return whether it succeeded
+     *
+     * @return  bool
+     */
+    public function run();
+
+    /**
+     * Return a summary of all actions designated to run
+     *
+     * @return  array
+     */
+    public function getSummary();
+
+    /**
+     * Return a report of all actions that were run
+     *
+     * @return  array
+     */
+    public function getReport();
+}