Fix problems with generated user data
diff --git a/xos/openstack_observer/steps/sync_slivers.py b/xos/openstack_observer/steps/sync_slivers.py
index 1774e69..a1ea203 100644
--- a/xos/openstack_observer/steps/sync_slivers.py
+++ b/xos/openstack_observer/steps/sync_slivers.py
@@ -21,8 +21,8 @@
     observes=Sliver
 
     def get_userdata(self, sliver, pubkeys):
-        userdata = 'opencloud:\n   slicename: "%s"\n   hostname: "%s"\n   restapi_hostname: "%s"\n   restapi_port: "%s"\n' % (sliver.slice.name, sliver.node.name, RESTAPI_HOSTNAME, str(RESTAPI_PORT))
-        userdata += 'ssh-authorized-keys:\n'
+        userdata = '#cloud-config\n\nopencloud:\n   slicename: "%s"\n   hostname: "%s"\n   restapi_hostname: "%s"\n   restapi_port: "%s"\n' % (sliver.slice.name, sliver.node.name, RESTAPI_HOSTNAME, str(RESTAPI_PORT))
+        userdata += 'ssh_authorized_keys:\n'
         for key in pubkeys:
             userdata += '  - %s\n' % key
         return userdata