Add a configuration option for the default resource class

If no resource class is provided in a creation request, the value of
the new ``default_resource_class`` configuration option is used.

While this feature is implemented on the API level, it's not a part of
the API contract, so it's not covered by a microversion. It's particularly
important, because it allows this change to apply even to requests
using an old API version, thus making these versions usable after
the mandatory switch to resource classes in nova.

Change-Id: I58232d9c92d6ffca49d334e5fb7078bce19f1cb4
Closes-Bug: #1732190

ironic/api/controllers/v1/node.py

@@ -1643,6 +1643,9 @@ class NodesController(rest.RestController):
             self._check_names_acceptable([node.name], error_msg)
         node.provision_state = api_utils.initial_node_provision_state()
 
+        if not node.resource_class:
+            node.resource_class = CONF.default_resource_class
+
         new_node = objects.Node(context, **node.as_dict())
         notify.emit_start_notification(context, new_node, 'create',
                                        chassis_uuid=node.chassis_uuid)

ironic/conf/default.py

@@ -69,6 +69,9 @@ api_opts = [
                 default=False,
                 help=_('Enable pecan debug mode. WARNING: this is insecure '
                        'and should not be used in a production environment.')),
+    cfg.StrOpt('default_resource_class',
+               help=_('Resource class to use for new nodes when no resource '
+                      'class is provided in the creation request.')),
 ]
 
 driver_opts = [

ironic/tests/unit/api/controllers/v1/test_node.py

@@ -2267,6 +2267,37 @@ class TestPost(test_api_base.BaseApiTest):
         self.assertEqual(ndict['uuid'], result['uuid'])
         self.assertEqual(states.ENROLL, result['provision_state'])
 
+    def test_create_node_no_default_resource_class(self):
+        ndict = test_api_utils.post_get_test_node()
+        self.post_json('/nodes', ndict)
+
+        # newer version is needed to see the resource_class field
+        result = self.get_json('/nodes/%s' % ndict['uuid'],
+                               headers={api_base.Version.string: "1.21"})
+        self.assertIsNone(result['resource_class'])
+
+    def test_create_node_with_default_resource_class(self):
+        self.config(default_resource_class='class1')
+
+        ndict = test_api_utils.post_get_test_node()
+        self.post_json('/nodes', ndict)
+
+        # newer version is needed to see the resource_class field
+        result = self.get_json('/nodes/%s' % ndict['uuid'],
+                               headers={api_base.Version.string: "1.21"})
+        self.assertEqual('class1', result['resource_class'])
+
+    def test_create_node_explicit_resource_class(self):
+        self.config(default_resource_class='class1')
+
+        ndict = test_api_utils.post_get_test_node(resource_class='class2')
+        self.post_json('/nodes', ndict,
+                       headers={api_base.Version.string: "1.21"})
+
+        result = self.get_json('/nodes/%s' % ndict['uuid'],
+                               headers={api_base.Version.string: "1.21"})
+        self.assertEqual('class2', result['resource_class'])
+
     def test_create_node_doesnt_contain_id(self):
         # FIXME(comstud): I'd like to make this test not use the
         # dbapi, however, no matter what I do when trying to mock

releasenotes/notes/default-resource-class-e11bacfb01d6841b.yaml

@@ -0,0 +1,6 @@
+---
+features:
+  - |
+    Adds new configuration option ``[DEFAULT]default_resource_class`` that
+    specifies the resource class to use for new nodes when no resource class
+    is provided in the node creation request.