Merge "Block deleting compute services which are hosting instances" into stable/queens

1 files changed, 17 insertions, 1 deletions

diff --git a/nova/api/openstack/compute/services.py b/nova/api/openstack/compute/services.py
index 07db925dea..608d783c18 100644
--- a/nova/api/openstack/compute/services.py
+++ b/nova/api/openstack/compute/services.py
@@ -24,6 +24,7 @@ from nova import availability_zones
 from nova import compute
 from nova import exception
 from nova.i18n import _
+from nova import objects
 from nova.policies import services as services_policies
 from nova import servicegroup
 from nova import utils
@@ -189,7 +190,7 @@ class ServiceController(wsgi.Controller):
         return action(body, context)
 
     @wsgi.response(204)
-    @wsgi.expected_errors((400, 404))
+    @wsgi.expected_errors((400, 404, 409))
     def delete(self, req, id):
         """Deletes the specified service."""
         context = req.environ['nova.context']
@@ -211,6 +212,21 @@ class ServiceController(wsgi.Controller):
             service = self.host_api.service_get_by_id(context, id)
             # remove the service from all the aggregates in which it's included
             if service.binary == 'nova-compute':
+                # Check to see if there are any instances on this compute host
+                # because if there are, we need to block the service (and
+                # related compute_nodes record) delete since it will impact
+                # resource accounting in Placement and orphan the compute node
+                # resource provider.
+                # TODO(mriedem): Use a COUNT SQL query-based function instead
+                # of InstanceList.get_uuids_by_host for performance.
+                instance_uuids = objects.InstanceList.get_uuids_by_host(
+                    context, service['host'])
+                if instance_uuids:
+                    raise webob.exc.HTTPConflict(
+                        explanation=_('Unable to delete compute service that '
+                                      'is hosting instances. Migrate or '
+                                      'delete the instances first.'))
+
                 aggrs = self.aggregate_api.get_aggregates_by_host(context,
                                                                   service.host)
                 for ag in aggrs: