Add action that returns number of running VMs on the unit.

Closes-Bug: #1911011
Change-Id: If9ae646bc91b6389876830843bbf905596963054
func-test-pr: https://github.com/openstack-charmers/zaza-openstack-tests/pull/535

README.md

@@ -301,6 +301,7 @@ deployed then see file `actions.yaml`.
 * `disable`
 * `enable`
 * `hugepagereport`
+* `instance-count`
 * `list-compute-nodes`
 * `node-name`
 * `openstack-upgrade`

actions.yaml

@@ -12,6 +12,8 @@ register-to-cloud:
     README.md, section 'Cloud downscaling'.
 openstack-upgrade:
   description: Perform openstack upgrades. Config option action-managed-upgrade must be set to True.
+instance-count:
+  description: Return number of VM instances running on this unit.
 list-compute-nodes:
   description: List all nova-compute nodes registered in the Openstack cloud.
 node-name:

actions/cloud.py

@@ -137,6 +137,14 @@ def register_to_cloud():
     })
 
 
+def instance_count():
+    """Implementation of `instance-count` action."""
+    nova = cloud_utils.nova_client()
+    vm_count = cloud_utils.running_vms(nova)
+
+    function_set({'instance-count': vm_count})
+
+
 def list_computes():
     """Implementation of `list-compute-nodes` action."""
     nova = cloud_utils.nova_client()
@@ -156,6 +164,7 @@ ACTIONS = {
     'enable': enable,
     'remove-from-cloud': remove_from_cloud,
     'register-to-cloud': register_to_cloud,
+    'instance-count': instance_count,
     'list-compute-nodes': list_computes,
     'node-name': node_name,
 }

actions/instance-count

@@ -0,0 +1 @@
+cloud.py

unit_tests/test_actions_cloud.py

@@ -247,6 +247,19 @@ class TestRegisterToCloud(_ActionTestCase):
         cloud.function_fail.assert_not_called()
 
 
+class TestInstanceCount(_ActionTestCase):
+    NAME = 'instance-count'
+
+    def test_action_instance_count(self):
+        """Test 'instance-count' action"""
+        running_vms = 2
+        cloud.cloud_utils.running_vms.return_value = 2
+
+        self.call_action()
+
+        cloud.function_set.assert_called_with({'instance-count': running_vms})
+
+
 class TestListComputeNodes(_ActionTestCase):
     NAME = 'list-compute-nodes'