From d5d1d3b45a449b8b84aea0478712475bfb7ba26e Mon Sep 17 00:00:00 2001
From: Yun Xu <yunx@zillowgroup.com>
Date: Tue, 8 Aug 2017 21:58:10 -0700
Subject: [PATCH] add trigger before_start events in create_server

---
 sanic/app.py | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/sanic/app.py b/sanic/app.py
index f0ccad86..7587c0c2 100644
--- a/sanic/app.py
+++ b/sanic/app.py
@@ -633,14 +633,28 @@ class Sanic:
                 warnings.simplefilter('default')
             warnings.warn("stop_event will be removed from future versions.",
                           DeprecationWarning)
+
         server_settings = self._helper(
             host=host, port=port, debug=debug, ssl=ssl, sock=sock,
             loop=get_event_loop(), protocol=protocol,
             backlog=backlog, run_async=True,
             has_log=log_config is not None)
 
+        # Trigger before_start events
+        await self.trigger_events(server_settings.get('before_start', []), server_settings.get('loop'))
+
         return await serve(**server_settings)
 
+    async def trigger_events(self, events, loop):
+        """Trigger events (functions or async)
+        :param events: one or more sync or async functions to execute
+        :param loop: event loop
+        """
+        for event in events:
+            result = event(loop)
+            if isawaitable(result):
+                await result
+
     async def _run_request_middleware(self, request):
         # The if improves speed.  I don't know why
         if self.request_middleware: