placement: enable required traits from the flavor extra specs

This patch enables the flavor extra spec 'required:[traits]'. The
admin can specifiy a set of traits that a flavor required.

To enable this, the placement 1.17 is required, it added trait
support in the `GET /allocation_candidates` API. So bump the
minimal placement version requirement to 1.17 and update the
check in cmd `nova-status`.

Implement blueprint request-traits-in-nova

Change-Id: Ia51ace951e9a0402f873ce9751a8cd3c0283db08

doc/source/cli/nova-status.rst

@@ -103,7 +103,7 @@ Upgrade
 
   **17.0.0 (Queens)**
 
-  * Checks for the Placement API are modified to require version 1.14.
+  * Checks for the Placement API are modified to require version 1.17.
 
 See Also
 ========

nova/cmd/status.py

@@ -201,7 +201,7 @@ class UpgradeCommands(object):
             # provider support.
             # NOTE: If you bump this version, remember to update the history
             # section in the nova-status man page (doc/source/cli/nova-status).
-            needs_version = pkg_resources.parse_version("1.14")
+            needs_version = pkg_resources.parse_version("1.17")
             if max_version < needs_version:
                 msg = (_('Placement API version %(needed)s needed, '
                          'you have %(current)s.') %

nova/scheduler/client/report.py

@@ -327,16 +327,19 @@ class SchedulerReportClient(object):
         # existing behavior.  Once the GET /allocation_candidates API is
         # prepped to accept the whole shebang, we'll join up all the resources
         # and traits in the query string (via a new method on ResourceRequest).
-        resources = resources.get_request_group(None).resources
+        res = resources.get_request_group(None).resources
+        required_traits = resources.get_request_group(None).required_traits
 
         resource_query = ",".join(
             sorted("%s:%s" % (rc, amount)
-            for (rc, amount) in resources.items()))
+            for (rc, amount) in res.items()))
         qs_params = {
             'resources': resource_query,
         }
+        if required_traits:
+            qs_params['required'] = ",".join(required_traits)
 
-        version = '1.12'
+        version = '1.17'
         url = "/allocation_candidates?%s" % parse.urlencode(qs_params)
         resp = self.get(url, version=version)
         if resp.status_code == 200:
@@ -347,7 +350,7 @@ class SchedulerReportClient(object):
         msg = ("Failed to retrieve allocation candidates from placement API "
                "for filters %(resources)s. Got %(status_code)d: %(err_text)s.")
         args = {
-            'resources': resources,
+            'resources': res,
             'status_code': resp.status_code,
             'err_text': resp.text,
         }

nova/tests/unit/cmd/test_status.py

@@ -210,7 +210,7 @@ class TestPlacementCheck(test.NoDBTestCase):
             "versions": [
                 {
                     "min_version": "1.0",
-                    "max_version": "1.14",
+                    "max_version": "1.17",
                     "id": "v1.0"
                 }
             ]
@@ -230,7 +230,7 @@ class TestPlacementCheck(test.NoDBTestCase):
              "versions": [
                 {
                     "min_version": "1.0",
-                    "max_version": "1.14",
+                    "max_version": "1.17",
                     "id": "v1.0"
                 }
             ]
@@ -251,7 +251,7 @@ class TestPlacementCheck(test.NoDBTestCase):
         }
         res = self.cmd._check_placement()
         self.assertEqual(status.UpgradeCheckCode.FAILURE, res.code)
-        self.assertIn('Placement API version 1.14 needed, you have 0.9',
+        self.assertIn('Placement API version 1.17 needed, you have 0.9',
                       res.details)
 
 

nova/tests/unit/scheduler/client/test_report.py

@@ -1417,12 +1417,37 @@ class TestProviderOperations(SchedulerReportClientTestCase):
                 self.client.get_allocation_candidates(resources)
 
         expected_url = '/allocation_candidates?%s' % parse.urlencode(
-            {'resources': 'MEMORY_MB:1024,VCPU:1'})
+            {'resources': 'MEMORY_MB:1024,VCPU:1',
+             'required': 'CUSTOM_TRAIT1'})
         self.ks_adap_mock.get.assert_called_once_with(
-            expected_url, raise_exc=False, microversion='1.12')
+            expected_url, raise_exc=False, microversion='1.17')
         self.assertEqual(mock.sentinel.alloc_reqs, alloc_reqs)
         self.assertEqual(mock.sentinel.p_sums, p_sums)
 
+    def test_get_allocation_candidates_with_no_trait(self):
+        resp_mock = mock.Mock(status_code=200)
+        json_data = {
+            'allocation_requests': mock.sentinel.alloc_reqs,
+            'provider_summaries': mock.sentinel.p_sums,
+        }
+        resources = scheduler_utils.ResourceRequest.from_extra_specs({
+            'resources:VCPU': '1',
+            'resources:MEMORY_MB': '1024',
+            'resources1:DISK_GB': '30',
+        })
+
+        resp_mock.json.return_value = json_data
+        self.ks_adap_mock.get.return_value = resp_mock
+
+        alloc_reqs, p_sums, allocation_request_version = \
+                self.client.get_allocation_candidates(resources)
+
+        expected_url = '/allocation_candidates?%s' % parse.urlencode(
+            {'resources': 'MEMORY_MB:1024,VCPU:1'})
+        self.ks_adap_mock.get.assert_called_once_with(
+            expected_url, raise_exc=False, microversion='1.17')
+        self.assertEqual(mock.sentinel.alloc_reqs, alloc_reqs)
+
     def test_get_allocation_candidates_not_found(self):
         # Ensure _get_resource_provider() just returns None when the placement
         # API doesn't find a resource provider matching a UUID
@@ -1436,7 +1461,7 @@ class TestProviderOperations(SchedulerReportClientTestCase):
 
         expected_url = '/allocation_candidates?resources=MEMORY_MB%3A1024'
         self.ks_adap_mock.get.assert_called_once_with(
-            expected_url, raise_exc=False, microversion='1.12')
+            expected_url, raise_exc=False, microversion='1.17')
         self.assertIsNone(res[0])
 
     def test_get_resource_provider_found(self):

releasenotes/notes/request-traits-in-nova-ffcb00f76229b6e9.yaml

@@ -0,0 +1,14 @@
+---
+features:
+  - |
+    Add traits support to the Nova. The new flavor extra spec is added to
+    support specifying the required traits. The syntax of extra spec is
+    as below:
+
+    - trait:HW_CPU_X86_AVX2=required
+    - trait:STORAGE_DISK_SSD=required
+
+    The scheduler will pass traits to the GET /allocation_candidates endpoint
+    in the Placement API to filter out resource providers with each of the
+    required traits. Currently the only valid value is required. For any other
+    value will be considered as invalid.