NRPE services is a list not a string

Pass charm-helpers' nrpe.add_init_service_checks() a list of services
as its second argument, instead of a string.

Additionally adjust amulet tests to configure hacluster's cluster_count
when > 1 unit is configured.

Change-Id: Ib48a31e17c1e8d8c68e774b64fcf52c0ee99bef5
Closes-Bug: 1643855

hooks/percona_hooks.py

@@ -699,7 +699,7 @@ def update_nrpe_config():
     hostname = nrpe.get_nagios_hostname()
     current_unit = nrpe.get_nagios_unit_name()
     nrpe_setup = nrpe.NRPE(hostname=hostname)
-    nrpe.add_init_service_checks(nrpe_setup, 'mysql', current_unit)
+    nrpe.add_init_service_checks(nrpe_setup, ['mysql'], current_unit)
     nrpe_setup.add_check(
         shortname='mysql_proc',
         description='Check MySQL process {%s}' % current_unit,

tests/basic_deployment.py

@@ -72,6 +72,7 @@ class BasicDeployment(OpenStackAmuletDeployment):
 
         configs = {'percona-cluster': cfg_percona}
         if self.units > 1:
+            cfg_ha['cluster_count'] = str(self.units)
             configs['hacluster'] = cfg_ha
 
         return configs

unit_tests/test_percona_hooks.py

@@ -192,3 +192,18 @@ class TestHostResolution(CharmTestCase):
         self.resolve_network_cidr.return_value = '192.168.20.2/24'
         self.assertEqual(hooks.get_db_host('myclient'), '192.168.20.200')
         self.network_get_primary_address.assert_called_with('shared-db')
+
+
+class TestNRPERelation(CharmTestCase):
+    def setUp(self):
+        patch_targets_nrpe = TO_PATCH[:]
+        patch_targets_nrpe.remove("update_nrpe_config")
+        patch_targets_nrpe.append("nrpe")
+        patch_targets_nrpe.append("apt_install")
+        CharmTestCase.setUp(self, hooks, patch_targets_nrpe)
+
+    def test_mysql_monitored(self):
+        """The mysql service is monitored by Nagios."""
+        hooks.update_nrpe_config()
+        self.nrpe.add_init_service_checks.assert_called_once_with(
+            mock.ANY, ["mysql"], mock.ANY)