Add additional capabilities for computes

This allows compute hosts to advertise additional capabilities
for use by custom schedulers. This is an interim solution to
provide this functionality until it is replaced by more general
HostAggregate functionality later in Folsom.

Change-Id: Ia288146fa92aec61f50641c2e4f7a3580ab03a32

2 files changed, 58 insertions, 3 deletions

diff --git a/nova/compute/manager.py b/nova/compute/manager.py
index 0fe261948..0366b4568 100644
--- a/nova/compute/manager.py
+++ b/nova/compute/manager.py
@@ -124,7 +124,15 @@ compute_opts = [
     cfg.IntOpt("heal_instance_info_cache_interval",
                default=60,
                help="Number of seconds between instance info_cache self "
-                        "healing updates")
+                        "healing updates"),
+    cfg.ListOpt('additional_compute_capabilities',
+               default=[],
+               help='a list of additional capabilities for this compute '
+               'host to advertise. Valid entries are name=value pairs '
+               'this functionality will be replaced when HostAggregates '
+               'become more funtional for general grouping in Folsom. (see: '
+               'http://etherpad.openstack.org/FolsomNovaHostAggregates-v2)'),
+
     ]
 
 FLAGS = flags.FLAGS
@@ -190,6 +198,21 @@ def _get_image_meta(context, image_ref):
     return image_service.show(context, image_id)
 
 
+def _get_additional_capabilities():
+    """Return additional capabilities to advertise for this compute host
+    This will be replaced once HostAggrgates are able to handle more general
+    host grouping for custom schedulers."""
+    capabilities = {}
+    for cap in FLAGS.additional_compute_capabilities:
+        if '=' in cap:
+            name, value = cap.split('=', 1)
+        else:
+            name = cap
+            value = True
+        capabilities[name] = value
+    return capabilities
+
+
 class ComputeManager(manager.SchedulerDependentManager):
     """Manages the running instances from creation to destruction."""
 
@@ -2265,8 +2288,9 @@ class ComputeManager(manager.SchedulerDependentManager):
             LOG.info(_("Updating host status"))
             # This will grab info about the host and queue it
             # to be sent to the Schedulers.
-            self.update_service_capabilities(
-                self.driver.get_host_stats(refresh=True))
+            capabilities = _get_additional_capabilities()
+            capabilities.update(self.driver.get_host_stats(refresh=True))
+            self.update_service_capabilities(capabilities)
 
     @manager.periodic_task(ticks_between_runs=10)
     def _sync_power_states(self, context):
diff --git a/nova/tests/test_compute.py b/nova/tests/test_compute.py
index adb50806d..348a7af0f 100644
--- a/nova/tests/test_compute.py
+++ b/nova/tests/test_compute.py
@@ -56,6 +56,7 @@ LOG = logging.getLogger(__name__)
 FLAGS = flags.FLAGS
 flags.DECLARE('stub_network', 'nova.compute.manager')
 flags.DECLARE('live_migration_retry_count', 'nova.compute.manager')
+flags.DECLARE('additional_compute_capabilities', 'nova.compute.manager')
 
 
 orig_rpc_call = rpc.call
@@ -1616,6 +1617,36 @@ class ComputeTestCase(BaseTestCase):
         self.compute.add_instance_fault_from_exc(ctxt, instance_uuid,
                                                  NotImplementedError('test'))
 
+    def test_get_additional_capabilities(self):
+        self.flags(additional_compute_capabilities=['test3=xyzzy',
+                                                    'test4',
+                                                    'nothertest=blat'])
+        caps = compute_manager._get_additional_capabilities()
+        all_caps = dict(test3='xyzzy',
+                        test4=True,
+                        nothertest='blat')
+        for c, val in all_caps.items():
+            self.assertTrue(c in caps, c)
+            self.assertEquals(val, caps[c])
+
+    def test_report_driver_status(self):
+        test_caps = dict(test1=1024, test2='foo', nothertest='bar')
+        self.flags(additional_compute_capabilities=['test3=xyzzy',
+                                                    'test4',
+                                                    'nothertest=blat'])
+        self.mox.StubOutWithMock(self.compute.driver, 'get_host_stats')
+        self.compute.driver.get_host_stats(refresh=True).AndReturn(test_caps)
+        self.compute._last_host_check = 0
+        self.mox.ReplayAll()
+
+        self.compute._report_driver_status(context)
+        caps = self.compute.last_capabilities
+        all_caps = dict(test1=1024, test2='foo', test3='xyzzy',
+                        test4=True, nothertest='bar')
+        for c, val in all_caps.items():
+            self.assertTrue(c in caps, c)
+            self.assertEquals(val, caps[c])
+
     def test_cleanup_running_deleted_instances(self):
         admin_context = context.get_admin_context()
         deleted_at = utils.utcnow() - datetime.timedelta(hours=1, minutes=5)