Start the http request handler for load balancing as a thread in Governor.

When not running standalone, some better referencing to the Postgresql instance was needed.

governor.py

@@ -2,10 +2,12 @@
 
 import sys, os, yaml, time, urllib2, atexit
 import logging
+import threading
 
 from helpers.etcd import Etcd
 from helpers.postgresql import Postgresql
 from helpers.ha import Ha
+from helpers.statuspage import StatusPage, getHTTPServer
 
 INSTANCE_METADATA_URL = "http://169.254.169.254/latest/meta-data/"
 
@@ -30,6 +32,12 @@ etcd = Etcd(config["etcd"])
 postgresql = Postgresql(config["postgresql"], aws_host_address)
 ha = Ha(postgresql, etcd)
 
+## Start the http_server to serve a simple healthcheck
+http_server = getHTTPServer(postgresql, http_port=8080, listen_address='0.0.0.0')
+http_thread = threading.Thread(target=http_server.serve_forever, args=())
+http_thread.daemon = True
+http_thread.start()
+
 # stop postgresql on script exit
 def stop_postgresql():
     postgresql.stop()

helpers/statuspage.py

@@ -1,7 +1,7 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
-from BaseHTTPServer import BaseHTTPRequestHandler
+from BaseHTTPServer import BaseHTTPRequestHandler, HTTPServer
 
 
 class StatusPage(BaseHTTPRequestHandler):
@@ -9,19 +9,21 @@ class StatusPage(BaseHTTPRequestHandler):
     def do_GET(self):
         try:
             if self.path == '/pg_master':
-                response = (200 if postgresql.is_leader else 503)
+                response = (200 if self.server.postgresql.is_leader else 503)
                 self.send_response(response)
             elif self.path == '/pg_slave':
-                response = (503 if postgresql.is_leader else 200)
+                response = (503 if self.server.postgresql.is_leader else 200)
                 self.send_response(response)
             elif self.path == '/pg_status':
                 self.send_response(200)
                 self.end_headers()
-                self.wfile.write(postgresql.status())
+                self.wfile.write(self.server.postgresql.status())
             else:
                 self.send_response(404)
-        except:
+        except Exception, e:
             self.send_response(500)
+            self.end_headers()
+            self.wfile.write(repr(e))
 
 
 def getHTTPServer(postgresql, http_port=8081, listen_address='0.0.0.0'):