Use ServiceGroup API to show node liveness

Previously it's direct db access. Now we use the servicegroup
API to show node liveness. Note that db access is still needed
to get other service attributes such as `disabled'.

Change-Id: I65ef3a136fd90036a8d009ed97a5f48ae461d8d9

bin/nova-manage

@@ -87,6 +87,7 @@ from nova.openstack.common import rpc
 from nova.openstack.common import timeutils
 from nova import quota
 from nova.scheduler import rpcapi as scheduler_rpcapi
+from nova import servicegroup
 from nova import utils
 from nova import version
 
@@ -624,6 +625,7 @@ class ServiceCommands(object):
         """
         Show a list of all running services. Filter by host & service name.
         """
+        servicegroup_api = servicegroup.API()
         ctxt = context.get_admin_context()
         now = timeutils.utcnow()
         services = db.service_get_all(ctxt)
@@ -641,8 +643,7 @@ class ServiceCommands(object):
                     _('State'),
                     _('Updated_At'))
         for svc in services:
-            delta = now - (svc['updated_at'] or svc['created_at'])
-            alive = abs(utils.total_seconds(delta)) <= CONF.service_down_time
+            alive = servicegroup_api.service_is_up(svc)
             art = (alive and ":-)") or "XXX"
             active = 'enabled'
             if svc['disabled']: