Zero downtime config reload (log handling)

Pick up changes to log configuration on reload.

Closes-bug: 1436274
Change-Id: I80dabe93729dd5ba7a27515aa78e5457413d0084

glance/common/wsgi.py

@@ -392,6 +392,10 @@ class Server(object):
         os.killpg(self.pgid, signal.SIGHUP)
         self.stale_children = self.children
         self.children = set()
+
+        # Ensure any logging config changes are picked up
+        logging.setup(CONF, 'glance')
+
         self.configure(old_conf, has_changed)
         self.start_wsgi()
 

glance/tests/functional/test_reload.py

@@ -238,3 +238,16 @@ class TestReload(functional.FunctionalTest):
         response = requests.get(path)
         self.assertEqual(300, response.status_code)
         del response
+
+        # Test logging configuration change
+        # This recycles the existing socket
+        conf_dir = os.path.join(self.test_dir, 'etc')
+        log_file = conf_dir + 'new.log'
+        self.assertFalse(os.path.exists(log_file))
+        set_config_value(self._conffile('api'), 'log_file', log_file)
+        cmd = "kill -HUP %s" % self._get_parent('api')
+        execute(cmd, raise_error=True)
+        msg = 'No new log file created'
+        for _ in self.ticker(msg):
+            if os.path.exists(log_file):
+                break