Make ComputeCapabilitiesFilter work with Ironic

It is not currently possible to selectively associate a Nova flavor
with certain nodes in Ironic, beyond variances in the cpu/ram/disk.

The ComputeCapabilitiesFilter exists in Nova for just this purpose,
but the nova.virt.ironic driver is not propagating the correct
data up to the scheduler.

This patch parses the node.properties['capabilities'] as a series of
comma-separated k:v pairs and passes them up to Nova so that it can
be matched against flavor.extra_specs['capabilities'] by the
scheduler filter.

Co-Author: Matthew Gilliard <matthew.gilliard@hp.com>
DocImpact: adds the ability to specify multiple capabilities
           to a node for scheduling purposes
Closes-bug: 1339816
Change-Id: Ide39f4a2796b169025bf0083e021166ae35f30f8

2 files changed, 50 insertions, 4 deletions

diff --git a/ironic/nova/tests/virt/ironic/test_driver.py b/ironic/nova/tests/virt/ironic/test_driver.py
index ec5921b66..1699fd525 100644
--- a/ironic/nova/tests/virt/ironic/test_driver.py
+++ b/ironic/nova/tests/virt/ironic/test_driver.py
@@ -150,6 +150,30 @@ class IronicDriverTestCase(test.NoDBTestCase):
         self.assertEqual(node_uuid, result['hypervisor_hostname'])
         self.assertEqual(stats, jsonutils.loads(result['stats']))
 
+    def test__node_resource_exposes_capabilities(self):
+        props = _get_properties()
+        props['capabilities'] = 'test:capability'
+        node = ironic_utils.get_test_node(properties=props)
+        result = self.driver._node_resource(node)
+        stats = jsonutils.loads(result['stats'])
+        self.assertIsNone(stats.get('capabilities'))
+        self.assertEqual('capability', stats.get('test'))
+
+    def test__node_resource_no_capabilities(self):
+        props = _get_properties()
+        props['capabilities'] = None
+        node = ironic_utils.get_test_node(properties=props)
+        result = self.driver._node_resource(node)
+        self.assertIsNone(jsonutils.loads(result['stats']).get('capabilities'))
+
+    def test__node_resource_malformed_capabilities(self):
+        props = _get_properties()
+        props['capabilities'] = 'test:capability,:no_key,no_val:'
+        node = ironic_utils.get_test_node(properties=props)
+        result = self.driver._node_resource(node)
+        stats = jsonutils.loads(result['stats'])
+        self.assertEqual('capability', stats.get('test'))
+
     def test__node_resource_no_instance_uuid(self):
         node_uuid = uuidutils.generate_uuid()
         props = _get_properties()
diff --git a/ironic/nova/virt/ironic/driver.py b/ironic/nova/virt/ironic/driver.py
index c67d63911..0a3544565 100644
--- a/ironic/nova/virt/ironic/driver.py
+++ b/ironic/nova/virt/ironic/driver.py
@@ -167,12 +167,9 @@ class IronicDriver(virt_driver.ComputeDriver):
         super(IronicDriver, self).__init__(virtapi)
 
         self.firewall_driver = firewall.load_driver(default=_FIREWALL_DRIVER)
-        # TODO(deva): sort out extra_specs and nova-scheduler interaction
         extra_specs = {}
         extra_specs["ironic_driver"] = \
             "ironic.nova.virt.ironic.driver.IronicDriver"
-        # cpu_arch set per node.
-        extra_specs['cpu_arch'] = ''
         for pair in CONF.ironic.instance_type_extra_specs:
             keyval = pair.split(':', 1)
             keyval[0] = keyval[0].strip()
@@ -201,9 +198,34 @@ class IronicDriver(virt_driver.ComputeDriver):
         memory_mb = int(node.properties.get('memory_mb', 0))
         local_gb = int(node.properties.get('local_gb', 0))
         cpu_arch = str(node.properties.get('cpu_arch', 'NotFound'))
-        nodes_extra_specs = self.extra_specs
+
+        nodes_extra_specs = self.extra_specs.copy()
+
+        # NOTE(deva): In Havana and Icehouse, the flavor was required to link
+        # to an arch-specific deploy kernel and ramdisk pair, and so the flavor
+        # also had to have extra_specs['cpu_arch'], which was matched against
+        # the ironic node.properties['cpu_arch'].
+        # With Juno, the deploy image(s) may be referenced directly by the
+        # node.driver_info, and a flavor no longer needs to contain any of
+        # these three extra specs, though the cpu_arch may still be used
+        # in a heterogeneous environment, if so desired.
         nodes_extra_specs['cpu_arch'] = cpu_arch
 
+        # NOTE(gilliard): To assist with more precise scheduling, if the
+        # node.properties contains a key 'capabilities', we expect the value
+        # to be of the form "k1:v1,k2:v2,etc.." which we add directly as
+        # key/value pairs into the node_extra_specs to be used by the
+        # ComputeCapabilitiesFilter
+        capabilities = node.properties.get('capabilities')
+        if capabilities:
+            for capability in str(capabilities).split(','):
+                parts = capability.split(':')
+                if len(parts) == 2 and parts[0] and parts[1]:
+                    nodes_extra_specs[parts[0]] = parts[1]
+                else:
+                    LOG.warn(_LW("Ignoring malformed capability '%s'. "
+                                 "Format should be 'key:val'."), capability)
+
         vcpus_used = 0
         memory_mb_used = 0
         local_gb_used = 0