Fix issues in fab on xenial

1. Check that the services list is not empty in install_xenial_prerequisites
   so that empty string is not added to list of services
2. Change verify_service to use systemctl is-active and check the return code
   on xenial

Change-Id: Ie6ef9c653ac854d4c4bd25e99f32ac0dcf44f28a
Closes-Bug: #1662393

fabfile/tasks/install.py

@@ -39,13 +39,16 @@ def disable_sysv_auto_generation():
 @parallel(pool_size=20)
 @roles('all')
 def install_xenial_prerequisites():
+    services_list = []
     contrail_systemd_services = run("ls -l /etc/systemd/system | grep .service | grep contrail | awk '{print $9}'")
-    services_list = contrail_systemd_services.split('\r\n')
+    if contrail_systemd_services:
+        services_list = contrail_systemd_services.split('\r\n')
 
     nova_systemd_services = run("ls -l /etc/systemd/system | grep .service | grep nova | awk '{print $9}'")
-    nova_services_list =  nova_systemd_services.split('\r\n')
-    for svc in nova_services_list:
-         services_list.append(svc)
+    if nova_systemd_services:
+        nova_services_list =  nova_systemd_services.split('\r\n')
+        for svc in nova_services_list:
+            services_list.append(svc)
 
     other_services = ['cassandra.service', 'ifmap.service', 'zookeeper.service']
     for svc in other_services:

fabfile/tasks/verify.py

@@ -10,11 +10,15 @@
 class OpenStackSetupError(Exception):
     pass
 
-def verify_service(service, initd_service=False):
+def verify_service(service, check_return_code=False):
     for x in xrange(10):
         with settings(warn_only=True):
-            output = sudo("service %s status" % service)
-        if initd_service:
+            if is_xenial_or_above():
+                output = sudo("systemctl is-active %s" % service)
+                check_return_code = True
+            else:
+                output = sudo("service %s status" % service)
+        if check_return_code:
             if output.succeeded or re.search('Active:.*active', output):
                 return
             else:
@@ -31,7 +35,7 @@ def verify_service(service, initd_service=False):
 def verify_database():
     if not is_xenial_or_above():
         verify_service("supervisor-database")
-    verify_service("contrail-database", initd_service=True)
+    verify_service("contrail-database", check_return_code=True)
 
 @task
 @roles('webui')
@@ -66,7 +70,7 @@ def verify_openstack():
 def verify_cfgm():
     verify_service("zookeeper")
     if manage_config_db():
-        verify_service("contrail-database", initd_service=True)
+        verify_service("contrail-database", check_return_code=True)
     if not is_xenial_or_above():
         verify_service("supervisor-config")
     verify_service("contrail-api")