Add timeout to prevent cloudbase-init service being stuck in offline state
for long time.
This has not been committed upstream, but has been filed in launchpad:

https://bugs.launchpad.net/cloudbase-init/+bug/1630006

--- cloudbase-init-0.9.9/cloudbaseinit/metadata/services/httpservice.py.orig	2016-09-06 14:29:04.416253079 +0000
+++ cloudbase-init-0.9.9/cloudbaseinit/metadata/services/httpservice.py	2016-09-06 14:39:14.807656387 +0000
@@ -58,7 +58,7 @@
 
     def _get_response(self, req):
         try:
-            return request.urlopen(req)
+            return request.urlopen(req, timeout=1)
         except error.HTTPError as ex:
             if ex.code == 404:
                 raise base.NotExistingMetadataException()
--- cloudbase-init-0.9.9/cloudbaseinit/metadata/services/ec2service.py.orig	2016-09-06 14:29:11.956815039 +0000
+++ cloudbase-init-0.9.9/cloudbaseinit/metadata/services/ec2service.py	2016-09-06 14:40:09.253600964 +0000
@@ -60,7 +60,7 @@
 
     def _get_response(self, req):
         try:
-            return request.urlopen(req)
+            return request.urlopen(req, timeout=1)
         except error.HTTPError as ex:
             if ex.code == 404:
                 raise base.NotExistingMetadataException()
--- cloudbase-init-0.9.9/cloudbaseinit/metadata/services/maasservice.py.orig	2016-09-06 14:29:26.753303424 +0000
+++ cloudbase-init-0.9.9/cloudbaseinit/metadata/services/maasservice.py	2016-09-06 14:40:40.454202962 +0000
@@ -79,7 +79,7 @@
 
     def _get_response(self, req):
         try:
-            return request.urlopen(req)
+            return request.urlopen(req, timeout=1)
         except error.HTTPError as ex:
             if ex.code == 404:
                 raise base.NotExistingMetadataException()
--- cloudbase-init-0.9.9/cloudbaseinit/metadata/services/cloudstack.py.orig	2016-09-22 14:25:30.411026974 +0000
+++ cloudbase-init-0.9.9/cloudbaseinit/metadata/services/cloudstack.py	2016-09-22 14:26:29.615140081 +0000
@@ -90,7 +90,7 @@
         """Get content for received url."""
         LOG.debug('Getting metadata from:  %s', url)
         request = urllib.request.Request(url, **kwargs)
-        response = urllib.request.urlopen(request)
+        response = urllib.request.urlopen(request, timeout=1)
         return response.read()
 
     def _get_data(self, path):