Make xenapi capabilities['enabled'] use service enabled

filters.compute_filter is enabled by default along with libvirt, but the
capabilities['enabled'] section of it is only supported by XenAPI.
This used to work by adding a parameter to capabilities, but since
the capabilities RPC is being removed, use conductor.service_update to tell
the scheduler which host is disabled.

service_update is already the way to tell the scheduler about other
disabled hosts, so to keep backwards compatibility keep host_enabled but
use service_update underneath.

Part of bp no-compute-fanout-to-scheduler

Change-Id: Ica1919cfe9a2402b2107c557c10d47e01a6c430b

nova/scheduler/filters/compute_filter.py

@@ -36,7 +36,6 @@ class ComputeFilter(filters.BaseHostFilter):
 
     def host_passes(self, host_state, filter_properties):
         """Returns True for only active compute nodes."""
-        capabilities = host_state.capabilities
         service = host_state.service
 
         alive = self.servicegroup_api.service_is_up(service)
@@ -44,8 +43,4 @@ class ComputeFilter(filters.BaseHostFilter):
             LOG.debug(_("%(host_state)s is disabled or has not been "
                     "heard from in a while"), {'host_state': host_state})
             return False
-        if not capabilities.get("enabled", True):
-            LOG.debug(_("%(host_state)s is disabled via capabilities"),
-                    {'host_state': host_state})
-            return False
         return True

nova/tests/scheduler/test_host_filters.py

@@ -671,17 +671,6 @@ class HostFiltersTestCase(test.NoDBTestCase):
                  'service': service})
         self.assertFalse(filt_cls.host_passes(host, filter_properties))
 
-    def test_compute_filter_fails_on_capability_disabled(self):
-        self._stub_service_is_up(True)
-        filt_cls = self.class_map['ComputeFilter']()
-        filter_properties = {'instance_type': {'memory_mb': 1024}}
-        capabilities = {'enabled': False}
-        service = {'disabled': False}
-        host = fakes.FakeHostState('host1', 'node1',
-                {'free_ram_mb': 1024, 'capabilities': capabilities,
-                 'service': service})
-        self.assertFalse(filt_cls.host_passes(host, filter_properties))
-
     def test_image_properties_filter_passes_same_inst_props(self):
         self._stub_service_is_up(True)
         filt_cls = self.class_map['ImagePropertiesFilter']()