Add post-init hook for workers

Allows a config specifying a function after a worker has been initialized and before the run loop

gunicorn/config.py

@@ -1162,6 +1162,24 @@ class Postfork(Setting):
         """
 
 
+class Postinit(Setting):
+    name = "post_init"
+    section = "Server Hooks"
+    validator = validate_callable(1)
+    type = six.callable
+
+    def post_init(worker):
+        pass
+
+    default = staticmethod(post_init)
+    desc = """\
+        Called just after a worker has initialized the application.
+
+        The callable needs to accept one instance variable for the initialized
+        Worker.
+        """
+
+
 class PreExec(Setting):
     name = "pre_exec"
     section = "Server Hooks"

gunicorn/workers/base.py

@@ -99,6 +99,8 @@ class Worker(object):
 
         self.wsgi = self.app.wsgi()
 
+        self.cfg.post_init(self)
+
         # Enter main run loop
         self.booted = True
         self.run()