Add support for showing scheduler_hints in server details

Nova currently lacks a straightforward way to expose scheduler hints
associated with a server. This change extends existing Nova's
API to allow users to retrieve this information when it is available.
It adds a new API microversion to support returning the associated
scheduler_hints in ``GET /servers/{server_id}``, `GET /servers/detail``,
``PUT /servers/{server_id}`` and ``POST /server/{server_id}/action``
(rebuild) responses.

Implements: blueprint show-scheduler-hints-in-server-details
Change-Id: If0070cfbc218e0515bf3b58fc8c5067ae22c7072

api-ref/source/parameters.yaml

@@ -6127,6 +6127,14 @@ running_vms_total:
   in: body
   required: true
   type: integer
+scheduler_hints:
+  description: |
+    The dictionary of hints sent to the scheduler during server
+    creation time.
+  in: body
+  required: true
+  type: object
+  min_version: 2.100
 secgroup_default_rule_id:
   description: |
     The security group default rule ID.

api-ref/source/servers-actions.inc

@@ -675,10 +675,15 @@ Response
   - os-extended-volumes:volumes_attached.delete_on_termination: os-extended-volumes:volumes_attached.delete_on_termination_update_rebuild
   - OS-SRV-USG:launched_at: OS-SRV-USG:launched_at_update_rebuild
   - OS-SRV-USG:terminated_at: OS-SRV-USG:terminated_at_update_rebuild
+  - scheduler_hints: scheduler_hints
   - security_groups: security_groups_obj_update_rebuild
   - security_group.name: name_update_rebuild
   - host_status: host_status_update_rebuild
 
+**Example Rebuild Server (rebuild Action) (v2.100)**
+
+.. literalinclude:: /../../doc/api_samples/servers/v2.100/server-action-rebuild-resp.json
+
 **Example Rebuild Server (rebuild Action) (v2.98)**
 
 .. literalinclude:: ../../doc/api_samples/servers/v2.98/server-action-rebuild-resp.json

api-ref/source/servers.inc

@@ -671,6 +671,7 @@ Response
   - fault.details: fault_details
   - pinned_availability_zone: pinned_availability_zone
   - progress: progress
+  - scheduler_hints: scheduler_hints
   - security_groups: security_groups_obj_optional
   - security_group.name: name
   - servers_links: servers_links
@@ -681,6 +682,11 @@ Response
   - trusted_image_certificates: server_trusted_image_certificates_resp
   - locked_reason: locked_reason_resp
 
+**Example List Servers Detailed (2.100)**
+
+.. literalinclude:: /../../doc/api_samples/servers/v2.100/servers-details-resp.json
+   :language: javascript
+
 **Example List Servers Detailed (2.98)**
 
 .. literalinclude:: /../../doc/api_samples/servers/v2.98/servers-details-resp.json
@@ -806,6 +812,7 @@ Response
   - fault.details: fault_details
   - pinned_availability_zone: pinned_availability_zone
   - progress: progress
+  - scheduler_hints: scheduler_hints
   - security_groups: security_groups_obj_optional
   - security_group.name: name
   - locked: locked
@@ -816,6 +823,11 @@ Response
   - server_groups: server_groups_2_71
   - locked_reason: locked_reason_resp
 
+**Example Show Server Details (2.100)**
+
+.. literalinclude:: ../../doc/api_samples/servers/v2.100/server-get-resp.json
+   :language: javascript
+
 **Example Show Server Details (2.98)**
 
 .. literalinclude:: ../../doc/api_samples/servers/v2.98/server-get-resp.json

doc/api_samples/servers/v2.100/server-action-rebuild-resp.json

@@ -0,0 +1,97 @@
+{
+    "server": {
+        "OS-DCF:diskConfig": "AUTO",
+        "OS-EXT-AZ:availability_zone": "us-west",
+        "OS-EXT-SRV-ATTR:hostname": "updated-hostname.example.com",
+        "OS-EXT-STS:power_state": 1,
+        "OS-EXT-STS:task_state": null,
+        "OS-EXT-STS:vm_state": "active",
+        "OS-SRV-USG:launched_at": "2021-08-19T15:16:22.177882",
+        "OS-SRV-USG:terminated_at": null,
+        "accessIPv4": "1.2.3.4",
+        "accessIPv6": "80fe::",
+        "addresses": {
+            "private": [
+                {
+                    "OS-EXT-IPS-MAC:mac_addr": "00:0c:29:0d:11:74",
+                    "OS-EXT-IPS:type": "fixed",
+                    "addr": "192.168.1.30",
+                    "version": 4
+                }
+            ]
+        },
+        "adminPass": "seekr3t",
+        "config_drive": "",
+        "created": "2019-04-23T17:10:22Z",
+        "description": null,
+        "flavor": {
+            "disk": 1,
+            "ephemeral": 0,
+            "extra_specs": {},
+            "original_name": "m1.tiny",
+            "ram": 512,
+            "swap": 0,
+            "vcpus": 1
+        },
+        "hostId": "2091634baaccdc4c5a1d57069c833e402921df696b7f970791b12ec6",
+        "id": "0c37a84a-c757-4f22-8c7f-0bf8b6970886",
+        "image": {
+            "id": "70a599e0-31e7-49b7-b260-868f441e862b",
+            "links": [
+                {
+                    "href": "http://openstack.example.com/6f70656e737461636b20342065766572/images/70a599e0-31e7-49b7-b260-868f441e862b",
+                    "rel": "bookmark"
+                }
+            ],
+            "properties": {
+                "architecture": "x86_64",
+                "auto_disk_config": "True",
+                "base_image_ref": "70a599e0-31e7-49b7-b260-868f441e862b",
+                "container_format": "ova",
+                "disk_format": "vhd",
+                "kernel_id": "nokernel",
+                "min_disk": "1",
+                "min_ram": "0",
+                "ramdisk_id": "nokernel"
+            }
+        },
+        "key_name": null,
+        "links": [
+            {
+                "href": "http://openstack.example.com/v2.1/6f70656e737461636b20342065766572/servers/0c37a84a-c757-4f22-8c7f-0bf8b6970886",
+                "rel": "self"
+            },
+            {
+                "href": "http://openstack.example.com/6f70656e737461636b20342065766572/servers/0c37a84a-c757-4f22-8c7f-0bf8b6970886",
+                "rel": "bookmark"
+            }
+        ],
+        "locked": false,
+        "locked_reason": null,
+        "metadata": {
+            "meta_var": "meta_val"
+        },
+        "name": "foobar",
+        "os-extended-volumes:volumes_attached": [],
+        "progress": 0,
+        "pinned_availability_zone": "us-west",
+        "scheduler_hints": {
+            "same_host": [
+                "48e6a9f6-30af-47e0-bc04-acaed113bb4e"
+            ]
+        },
+        "security_groups": [
+            {
+                "name": "default"
+            }
+        ],
+        "server_groups": [],
+        "status": "ACTIVE",
+        "tags": [],
+        "tenant_id": "6f70656e737461636b20342065766572",
+        "trusted_image_certificates": null,
+        "updated": "2019-04-23T17:10:24Z",
+        "user_data": "ZWNobyAiaGVsbG8gd29ybGQi",
+        "user_id": "fake"
+    }
+}

doc/api_samples/servers/v2.100/server-create-resp.json

@@ -0,0 +1,22 @@
+{
+    "server": {
+        "OS-DCF:diskConfig": "AUTO",
+        "adminPass": "6NpUwoz2QDRN",
+        "id": "f5dc173b-6804-445a-a6d8-c705dad5b5eb",
+        "links": [
+            {
+                "href": "http://openstack.example.com/v2/6f70656e737461636b20342065766572/servers/f5dc173b-6804-445a-a6d8-c705dad5b5eb",
+                "rel": "self"
+            },
+            {
+                "href": "http://openstack.example.com/6f70656e737461636b20342065766572/servers/f5dc173b-6804-445a-a6d8-c705dad5b5eb",
+                "rel": "bookmark"
+            }
+        ],
+        "security_groups": [
+            {
+                "name": "default"
+            }
+        ]
+    }
+}

doc/api_samples/servers/v2.100/server-get-resp.json

@@ -0,0 +1,98 @@
+{
+    "server": {
+        "accessIPv4": "1.2.3.4",
+        "accessIPv6": "80fe::",
+        "addresses": {
+            "private": [
+                {
+                    "addr": "192.168.1.30",
+                    "OS-EXT-IPS-MAC:mac_addr": "00:0c:29:0d:11:74",
+                    "OS-EXT-IPS:type": "fixed",
+                    "version": 4
+                }
+            ]
+        },
+        "created": "2013-09-03T04:01:32Z",
+        "description": null,
+        "locked": false,
+        "locked_reason": null,
+        "flavor": {
+            "disk": 1,
+            "ephemeral": 0,
+            "extra_specs": {},
+            "original_name": "m1.tiny",
+            "ram": 512,
+            "swap": 0,
+            "vcpus": 1
+        },
+        "hostId": "92154fab69d5883ba2c8622b7e65f745dd33257221c07af363c51b29",
+        "id": "0e44cc9c-e052-415d-afbf-469b0d384170",
+        "image": {
+            "id": "70a599e0-31e7-49b7-b260-868f441e862b",
+            "links": [
+                {
+                    "href": "http://openstack.example.com/6f70656e737461636b20342065766572/images/70a599e0-31e7-49b7-b260-868f441e862b",
+                    "rel": "bookmark"
+                }
+            ],
+            "properties": {
+                "architecture": "x86_64",
+                "auto_disk_config": "True",
+                "base_image_ref": "70a599e0-31e7-49b7-b260-868f441e862b",
+                "container_format": "ova",
+                "disk_format": "vhd",
+                "kernel_id": "nokernel",
+                "min_disk": "1",
+                "min_ram": "0",
+                "ramdisk_id": "nokernel"
+            }
+        },
+        "key_name": null,
+        "links": [
+            {
+                "href": "http://openstack.example.com/v2/6f70656e737461636b20342065766572/servers/0e44cc9c-e052-415d-afbf-469b0d384170",
+                "rel": "self"
+            },
+            {
+                "href": "http://openstack.example.com/6f70656e737461636b20342065766572/servers/0e44cc9c-e052-415d-afbf-469b0d384170",
+                "rel": "bookmark"
+            }
+        ],
+        "metadata": {
+            "My Server Name": "Apache1"
+        },
+        "name": "new-server-test",
+        "config_drive": "",
+        "OS-DCF:diskConfig": "AUTO",
+        "OS-EXT-AZ:availability_zone": "us-west",
+        "OS-EXT-SRV-ATTR:hostname": "new-server-test",
+        "OS-EXT-STS:power_state": 1,
+        "OS-EXT-STS:task_state": null,
+        "OS-EXT-STS:vm_state": "active",
+        "os-extended-volumes:volumes_attached": [
+            {"id": "volume_id1", "delete_on_termination": false},
+            {"id": "volume_id2", "delete_on_termination": false}
+        ],
+        "OS-SRV-USG:launched_at": "2013-09-23T13:37:00.880302",
+        "OS-SRV-USG:terminated_at": null,
+        "pinned_availability_zone": "us-west",
+        "progress": 0,
+        "scheduler_hints": {
+            "same_host": [
+                "48e6a9f6-30af-47e0-bc04-acaed113bb4e"
+            ]
+        },
+        "security_groups": [
+            {
+                "name": "default"
+            }
+        ],
+        "server_groups": [],
+        "status": "ACTIVE",
+        "tags": [],
+        "tenant_id": "6f70656e737461636b20342065766572",
+        "trusted_image_certificates": null,
+        "updated": "2013-09-03T04:01:33Z",
+        "user_id": "fake"
+    }
+}

doc/api_samples/servers/v2.100/server-update-req.json

@@ -0,0 +1,8 @@
+{
+    "server": {
+        "accessIPv4": "4.3.2.1",
+        "accessIPv6": "80fe::",
+        "OS-DCF:diskConfig": "AUTO",
+        "hostname" : "new-server-hostname.example.com"
+    }
+}

doc/api_samples/servers/v2.100/server-update-resp.json

@@ -0,0 +1,95 @@
+{
+    "server": {
+        "accessIPv4": "1.2.3.4",
+        "accessIPv6": "80fe::",
+        "addresses": {
+            "private": [
+                {
+                    "addr": "192.168.1.30",
+                    "OS-EXT-IPS-MAC:mac_addr": "00:0c:29:0d:11:74",
+                    "OS-EXT-IPS:type": "fixed",
+                    "version": 4
+                }
+            ]
+        },
+        "created": "2013-09-03T04:01:32Z",
+        "description": null,
+        "locked": false,
+        "locked_reason": null,
+        "flavor": {
+            "disk": 1,
+            "ephemeral": 0,
+            "extra_specs": {},
+            "original_name": "m1.tiny",
+            "ram": 512,
+            "swap": 0,
+            "vcpus": 1
+        },
+        "hostId": "92154fab69d5883ba2c8622b7e65f745dd33257221c07af363c51b29",
+        "id": "0e44cc9c-e052-415d-afbf-469b0d384170",
+        "image": {
+                "id": "70a599e0-31e7-49b7-b260-868f441e862b",
+                "links": [
+                    {
+                        "href": "http://openstack.example.com/6f70656e737461636b20342065766572/images/70a599e0-31e7-49b7-b260-868f441e862b",
+                        "rel": "bookmark"
+                    }
+                ],
+                "properties": {
+                    "architecture": "x86_64",
+                    "auto_disk_config": "True",
+                    "base_image_ref": "70a599e0-31e7-49b7-b260-868f441e862b",
+                    "container_format": "ova",
+                    "disk_format": "vhd",
+                    "kernel_id": "nokernel",
+                    "min_disk": "1",
+                    "min_ram": "0",
+                    "ramdisk_id": "nokernel"
+                }
+        },
+        "key_name": null,
+        "links": [
+            {
+                "href": "http://openstack.example.com/v2/6f70656e737461636b20342065766572/servers/0e44cc9c-e052-415d-afbf-469b0d384170",
+                "rel": "self"
+            },
+            {
+                "href": "http://openstack.example.com/6f70656e737461636b20342065766572/servers/0e44cc9c-e052-415d-afbf-469b0d384170",
+                "rel": "bookmark"
+            }
+        ],
+        "metadata": {
+            "My Server Name": "Apache1"
+        },
+        "name": "new-server-test",
+        "config_drive": "",
+        "OS-DCF:diskConfig": "AUTO",
+        "OS-EXT-AZ:availability_zone": "us-west",
+        "OS-EXT-SRV-ATTR:hostname": "new-server-hostname.example.com",
+        "OS-EXT-STS:power_state": 1,
+        "OS-EXT-STS:task_state": null,
+        "OS-EXT-STS:vm_state": "active",
+        "os-extended-volumes:volumes_attached": [],
+        "OS-SRV-USG:launched_at": "2013-09-23T13:37:00.880302",
+        "OS-SRV-USG:terminated_at": null,
+        "pinned_availability_zone": "us-west",
+        "progress": 0,
+        "scheduler_hints": {
+            "same_host": [
+                "48e6a9f6-30af-47e0-bc04-acaed113bb4e"
+            ]
+        },
+        "security_groups": [
+            {
+                "name": "default"
+            }
+        ],
+        "server_groups": [],
+        "status": "ACTIVE",
+        "tags": [],
+        "tenant_id": "6f70656e737461636b20342065766572",
+        "trusted_image_certificates": null,
+        "updated": "2013-09-03T04:01:33Z",
+        "user_id": "fake"
+    }
+}

doc/api_samples/servers/v2.100/servers-details-resp.json

@@ -0,0 +1,105 @@
+{
+    "servers": [
+        {
+            "accessIPv4": "1.2.3.4",
+            "accessIPv6": "80fe::",
+            "addresses": {
+                "private": [
+                    {
+                        "addr": "192.168.1.30",
+                        "OS-EXT-IPS-MAC:mac_addr": "00:0c:29:0d:11:74",
+                        "OS-EXT-IPS:type": "fixed",
+                        "version": 4
+                    }
+                ]
+            },
+            "created": "2013-09-03T04:01:32Z",
+            "description": "",
+            "flavor": {
+                "disk": 1,
+                "ephemeral": 0,
+                "extra_specs": {},
+                "original_name": "m1.tiny",
+                "ram": 512,
+                "swap": 0,
+                "vcpus": 1
+            },
+            "hostId": "bcf92836fc9ed4203a75cb0337afc7f917d2be504164b995c2334b25",
+            "id": "f5dc173b-6804-445a-a6d8-c705dad5b5eb",
+            "image": {
+                "id": "70a599e0-31e7-49b7-b260-868f441e862b",
+                "links": [
+                    {
+                        "href": "http://openstack.example.com/6f70656e737461636b20342065766572/images/70a599e0-31e7-49b7-b260-868f441e862b",
+                        "rel": "bookmark"
+                    }
+                ],
+                "properties": {
+                    "architecture": "x86_64",
+                    "auto_disk_config": "True",
+                    "base_image_ref": "70a599e0-31e7-49b7-b260-868f441e862b",
+                    "container_format": "ova",
+                    "disk_format": "vhd",
+                    "kernel_id": "nokernel",
+                    "min_disk": "1",
+                    "min_ram": "0",
+                    "ramdisk_id": "nokernel"
+                }
+            },
+            "key_name": null,
+            "links": [
+                {
+                    "href": "http://openstack.example.com/v2/6f70656e737461636b20342065766572/servers/f5dc173b-6804-445a-a6d8-c705dad5b5eb",
+                    "rel": "self"
+                },
+                {
+                    "href": "http://openstack.example.com/6f70656e737461636b20342065766572/servers/f5dc173b-6804-445a-a6d8-c705dad5b5eb",
+                    "rel": "bookmark"
+                }
+            ],
+            "metadata": {
+                "My Server Name": "Apache1"
+            },
+            "name": "new-server-test",
+            "config_drive": "",
+            "locked": false,
+            "locked_reason": "",
+            "OS-DCF:diskConfig": "AUTO",
+            "OS-EXT-AZ:availability_zone": "us-west",
+            "OS-EXT-SRV-ATTR:hostname": "new-server-test",
+            "OS-EXT-STS:power_state": 1,
+            "OS-EXT-STS:task_state": null,
+            "OS-EXT-STS:vm_state": "active",
+            "os-extended-volumes:volumes_attached": [
+                {"id": "volume_id1", "delete_on_termination": false},
+                {"id": "volume_id2", "delete_on_termination": false}
+            ],
+            "OS-SRV-USG:launched_at": "2013-09-23T13:53:12.774549",
+            "OS-SRV-USG:terminated_at": null,
+            "pinned_availability_zone": "us-west",
+            "progress": 0,
+            "scheduler_hints": {
+                "same_host": [
+                    "48e6a9f6-30af-47e0-bc04-acaed113bb4e"
+                ]
+            },
+            "security_groups": [
+                {
+                    "name": "default"
+                }
+            ],
+            "status": "ACTIVE",
+            "tags": [],
+            "tenant_id": "6f70656e737461636b20342065766572",
+            "trusted_image_certificates": null,
+            "updated": "2013-09-03T04:01:32Z",
+            "user_id": "fake"
+        }
+    ],
+    "servers_links": [
+        {
+            "href": "http://openstack.example.com/v2.1/6f70656e737461636b20342065766572/servers/detail?limit=1&marker=f5dc173b-6804-445a-a6d8-c705dad5b5eb",
+            "rel": "next"
+        }
+    ]
+}

doc/api_samples/servers/v2.100/servers-list-resp.json

@@ -0,0 +1,24 @@
+{
+    "servers": [
+        {
+            "id": "3cfb801c-f03c-45ce-834b-d097b34e9534",
+            "links": [
+                {
+                    "href": "http://openstack.example.com/v2/6f70656e737461636b20342065766572/servers/3cfb801c-f03c-45ce-834b-d097b34e9534",
+                    "rel": "self"
+                },
+                {
+                    "href": "http://openstack.example.com/6f70656e737461636b20342065766572/servers/3cfb801c-f03c-45ce-834b-d097b34e9534",
+                    "rel": "bookmark"
+                }
+            ],
+            "name": "new-server-test"
+        }
+    ],
+    "servers_links": [
+        {
+            "href": "http://openstack.example.com/v2.1/6f70656e737461636b20342065766572/servers?limit=1&marker=3cfb801c-f03c-45ce-834b-d097b34e9534",
+            "rel": "next"
+        }
+    ]
+}

doc/api_samples/versions/v21-version-get-resp.json

@@ -19,7 +19,7 @@
             }
         ],
         "status": "CURRENT",
-        "version": "2.99",
+        "version": "2.100",
         "min_version": "2.1",
         "updated": "2013-07-23T11:33:21Z"
     }

doc/api_samples/versions/versions-get-resp.json

@@ -22,7 +22,7 @@
                 }
             ],
             "status": "CURRENT",
-            "version": "2.99",
+            "version": "2.100",
             "min_version": "2.1",
             "updated": "2013-07-23T11:33:21Z"
         }

nova/api/openstack/api_version_request.py

@@ -269,6 +269,10 @@ REST_API_VERSION_HISTORY = """REST API Version History:
              ``server show`` and ``server list --long`` and in the ``server
              rebuild`` responses.
     * 2.99 - Add the spice-direct console type to the spice console protocol.
+    * 2.100 - Add support for returning associated scheduler_hints in
+             ``GET /servers/{server_id}``, ``GET /servers/detail``,
+             ``PUT /servers/{server_id}`` and
+             ``POST /server/{server_id}/action`` (rebuild) responses.
 """
 
 # The minimum and maximum versions of the API supported
@@ -277,7 +281,7 @@ REST_API_VERSION_HISTORY = """REST API Version History:
 # Note(cyeoh): This only applies for the v2.1 API once microversions
 # support is fully merged. It does not affect the V2 API.
 _MIN_API_VERSION = '2.1'
-_MAX_API_VERSION = '2.99'
+_MAX_API_VERSION = '2.100'
 DEFAULT_API_VERSION = _MIN_API_VERSION
 
 # Almost all proxy APIs which are related to network, images and baremetal

nova/api/openstack/compute/rest_api_version_history.rst

@@ -1288,3 +1288,13 @@ under the struct at the existing ``image`` key in the response for
 Add the ``spice-direct`` console type to the spice console protocol. Also
 add a ``tls_port`` field to the return value from
 ``GET /os-console-auth-tokens/{console_token}``.
+
+.. _microversion 2.100:
+
+2.100
+-----------------------------------------------------
+
+The ``GET /servers/{server_id}``, ``GET /servers/detail``
+``PUT /servers/{server_id}`` and ``POST /server/{server_id}/action``
+(rebuild) responses now include the scheduler hints provided during
+server creation.

nova/api/openstack/compute/schemas/servers.py

@@ -1244,3 +1244,11 @@ rebuild_response_v298['properties']['server']['properties']['image'][
             'additionalProperties': False,
     },
 })
+
+rebuild_response_v2100 = copy.deepcopy(rebuild_response_v298)
+rebuild_response_v2100['properties']['server']['properties'].update({
+    'scheduler_hints': _hints,
+})
+rebuild_response_v2100['properties']['server']['required'].append(
+    'scheduler_hints'
+)

nova/api/openstack/compute/servers.py

@@ -1190,7 +1190,9 @@ class ServersController(wsgi.Controller):
     @validation.response_body_schema(
         schema.rebuild_response_v296, '2.96', '2.97')
     @validation.response_body_schema(
-        schema.rebuild_response_v298, '2.98')
+        schema.rebuild_response_v298, '2.98', '2.99')
+    @validation.response_body_schema(
+        schema.rebuild_response_v2100, '2.100')
     def _action_rebuild(self, req, id, body):
         """Rebuild an instance with the given attributes."""
         rebuild_dict = body['rebuild']

nova/api/openstack/compute/views/servers.py

@@ -41,6 +41,9 @@ from nova import utils
 LOG = logging.getLogger(__name__)
 
 
+SCHED_HINTS_NOT_IN_REQUEST_SPEC = object()
+
+
 class ViewBuilder(common.ViewBuilder):
     """Model a server API response as a python dictionary."""
 
@@ -96,7 +99,8 @@ class ViewBuilder(common.ViewBuilder):
     def basic(self, request, instance, show_extra_specs=False,
               show_extended_attr=None, show_host_status=None,
               show_sec_grp=None, bdms=None, cell_down_support=False,
-              show_user_data=False, provided_az=None):
+              show_user_data=False, provided_az=None,
+              provided_sched_hints=None):
         """Generic, non-detailed view of an instance."""
         if cell_down_support and 'display_name' not in instance:
             # NOTE(tssurya): If the microversion is >= 2.69, this boolean will
@@ -233,13 +237,29 @@ class ViewBuilder(common.ViewBuilder):
                 pinned_az = ''
         return pinned_az
 
+    def _get_scheduler_hints(self, context, instance, provided_sched_hints):
+        if provided_sched_hints is SCHED_HINTS_NOT_IN_REQUEST_SPEC:
+            # Case where it was pre fetched, but not specified
+            sched_hints = None
+        elif provided_sched_hints is not None:
+            sched_hints = provided_sched_hints
+        else:
+            # Case the provided_az is not pre fethed.
+            try:
+                req_spec = objects.RequestSpec.get_by_instance_uuid(
+                        context, instance.uuid)
+                sched_hints = req_spec.scheduler_hints
+            except exception.RequestSpecNotFound:
+                sched_hints = {}
+        return sched_hints
+
     def show(self, request, instance, extend_address=True,
              show_extra_specs=None, show_AZ=True, show_config_drive=True,
              show_extended_attr=None, show_host_status=None,
              show_keypair=True, show_srv_usg=True, show_sec_grp=True,
              show_extended_status=True, show_extended_volumes=True,
              bdms=None, cell_down_support=False, show_server_groups=False,
-             show_user_data=True, provided_az=None):
+             show_user_data=True, provided_az=None, provided_sched_hints=None):
         """Detailed view of a single instance."""
         if show_extra_specs is None:
             # detail will pre-calculate this for us. If we're doing show,
@@ -300,6 +320,7 @@ class ViewBuilder(common.ViewBuilder):
             server["server"]["progress"] = instance.get("progress", 0)
 
         context = request.environ['nova.context']
+
         if show_AZ:
             az = avail_zone.get_instance_availability_zone(context, instance)
             # NOTE(mriedem): The OS-EXT-AZ prefix should not be used for new
@@ -310,6 +331,11 @@ class ViewBuilder(common.ViewBuilder):
                 pinned_az = self._get_pinned_az(context, instance, provided_az)
                 server['server']['pinned_availability_zone'] = pinned_az
 
+        if api_version_request.is_supported(request, min_version='2.100'):
+            server['server']['scheduler_hints'] = (
+                    self._get_scheduler_hints(
+                        context, instance, provided_sched_hints))
+
         if show_config_drive:
             server["server"]["config_drive"] = instance["config_drive"]
 
@@ -518,6 +544,7 @@ class ViewBuilder(common.ViewBuilder):
         """
         req_specs = None
         req_specs_dict = collections.defaultdict(str)
+        sched_hints_dict = {}
         if api_version_request.is_supported(request, min_version='2.96'):
             context = request.environ['nova.context']
             instance_uuids = [s.uuid for s in servers]
@@ -525,18 +552,27 @@ class ViewBuilder(common.ViewBuilder):
                     context, instance_uuids)
             req_specs_dict = {req.instance_uuid: req.availability_zone
                               for req in req_specs}
+            if api_version_request.is_supported(request, min_version='2.100'):
+                sched_hints_dict.update({
+                    req.instance_uuid: req.scheduler_hints
+                    for req in req_specs
+                    if req.scheduler_hints is not None})
 
-        server_list = [func(request, server,
+        server_list = [
-                            show_extra_specs=show_extra_specs,
+            func(request, server,
-                            show_extended_attr=show_extended_attr,
+                 show_extra_specs=show_extra_specs,
-                            show_host_status=show_host_status,
+                 show_extended_attr=show_extended_attr,
-                            show_sec_grp=show_sec_grp, bdms=bdms,
+                 show_host_status=show_host_status,
-                            cell_down_support=cell_down_support,
+                 show_sec_grp=show_sec_grp, bdms=bdms,
-                            provided_az=req_specs_dict[server.uuid])["server"]
+                 cell_down_support=cell_down_support,
-                       for server in servers
+                 provided_az=req_specs_dict[server.uuid],
-                       # Filter out the fake marker instance created by the
+                 provided_sched_hints=sched_hints_dict.get(
-                       # fill_virtual_interface_list online data migration.
+                     server.uuid, SCHED_HINTS_NOT_IN_REQUEST_SPEC)
-                       if server.uuid != virtual_interface.FAKE_UUID]
+                 )["server"]
+            for server in servers
+            # Filter out the fake marker instance created by the
+            # fill_virtual_interface_list online data migration.
+            if server.uuid != virtual_interface.FAKE_UUID]
         servers_links = self._get_collection_links(request,
                                                    servers,
                                                    coll_name)

nova/tests/functional/api_sample_tests/api_samples/servers/v2.100/server-action-rebuild-resp.json.tpl

@@ -0,0 +1,97 @@
+{
+    "server": {
+        "OS-DCF:diskConfig": "AUTO",
+        "OS-EXT-AZ:availability_zone": "us-west",
+        "OS-EXT-SRV-ATTR:hostname": "updated-hostname.example.com",
+        "OS-EXT-STS:power_state": 1,
+        "OS-EXT-STS:task_state": null,
+        "OS-EXT-STS:vm_state": "active",
+        "OS-SRV-USG:launched_at": "%(strtime)s",
+        "OS-SRV-USG:terminated_at": null,
+        "accessIPv4": "1.2.3.4",
+        "accessIPv6": "80fe::",
+        "addresses": {
+            "private": [
+                {
+                    "OS-EXT-IPS-MAC:mac_addr": "00:0c:29:0d:11:74",
+                    "OS-EXT-IPS:type": "fixed",
+                    "addr": "192.168.1.30",
+                    "version": 4
+                }
+            ]
+        },
+        "adminPass": "seekr3t",
+        "config_drive": "",
+        "created": "%(isotime)s",
+        "description": null,
+        "flavor": {
+            "disk": 1,
+            "ephemeral": 0,
+            "extra_specs": {},
+            "original_name": "m1.tiny",
+            "ram": 512,
+            "swap": 0,
+            "vcpus": 1
+        },
+        "hostId": "2091634baaccdc4c5a1d57069c833e402921df696b7f970791b12ec6",
+        "id": "%(id)s",
+        "image": {
+            "id": "%(uuid)s",
+            "links": [
+                {
+                    "href": "%(compute_endpoint)s/images/%(uuid)s",
+                    "rel": "bookmark"
+                }
+            ],
+            "properties": {
+                "architecture": "x86_64",
+                "auto_disk_config": "True",
+                "base_image_ref": "%(uuid)s",
+                "container_format": "ova",
+                "disk_format": "vhd",
+                "kernel_id": "nokernel",
+                "min_disk": "1",
+                "min_ram": "0",
+                "ramdisk_id": "nokernel"
+            }
+        },
+        "key_name": null,
+        "links": [
+            {
+                "href": "%(versioned_compute_endpoint)s/servers/%(uuid)s",
+                "rel": "self"
+            },
+            {
+                "href": "%(compute_endpoint)s/servers/%(id)s",
+                "rel": "bookmark"
+            }
+        ],
+        "locked": false,
+        "locked_reason": null,
+        "metadata": {
+            "meta_var": "meta_val"
+        },
+        "name": "foobar",
+        "os-extended-volumes:volumes_attached": [],
+        "pinned_availability_zone": "us-west",
+        "progress": 0,
+        "scheduler_hints": {
+            "same_host": [
+                "48e6a9f6-30af-47e0-bc04-acaed113bb4e"
+            ]
+        },
+        "security_groups": [
+            {
+                "name": "default"
+            }
+        ],
+        "server_groups": [],
+        "status": "ACTIVE",
+        "tags": [],
+        "tenant_id": "6f70656e737461636b20342065766572",
+        "trusted_image_certificates": null,
+        "updated": "%(isotime)s",
+        "user_data": "ZWNobyAiaGVsbG8gd29ybGQi",
+        "user_id": "fake"
+    }
+}

nova/tests/functional/api_sample_tests/api_samples/servers/v2.100/server-action-rebuild.json.tpl

@@ -0,0 +1,15 @@
+{
+    "rebuild" : {
+        "accessIPv4" : "%(access_ip_v4)s",
+        "accessIPv6" : "%(access_ip_v6)s",
+        "OS-DCF:diskConfig": "AUTO",
+        "imageRef" : "%(uuid)s",
+        "name" : "%(name)s",
+        "adminPass" : "%(pass)s",
+        "hostname": "%(hostname)s",
+        "metadata" : {
+            "meta_var" : "meta_val"
+        },
+        "user_data": "ZWNobyAiaGVsbG8gd29ybGQi"
+    }
+}

nova/tests/functional/api_sample_tests/api_samples/servers/v2.100/server-create-req.json.tpl

@@ -0,0 +1,25 @@
+{
+    "server" : {
+        "accessIPv4": "%(access_ip_v4)s",
+        "accessIPv6": "%(access_ip_v6)s",
+        "name" : "new-server-test",
+        "imageRef" : "%(image_id)s",
+        "flavorRef" : "1",
+        "OS-DCF:diskConfig": "AUTO",
+        "availability_zone": "%(availability_zone)s",
+        "metadata" : {
+            "My Server Name" : "Apache1"
+        },
+        "security_groups": [
+            {
+                "name": "default"
+            }
+        ],
+        "user_data" : "%(user_data)s",
+        "networks": "auto",
+        "hostname": "new-server-test"
+    },
+    "OS-SCH-HNT:scheduler_hints": {
+        "same_host": "48e6a9f6-30af-47e0-bc04-acaed113bb4e"
+    }
+}

nova/tests/functional/api_sample_tests/api_samples/servers/v2.100/server-create-resp.json.tpl

@@ -0,0 +1,22 @@
+{
+    "server": {
+        "OS-DCF:diskConfig": "AUTO",
+        "adminPass": "%(password)s",
+        "id": "%(id)s",
+        "links": [
+            {
+                "href": "%(versioned_compute_endpoint)s/servers/%(uuid)s",
+                "rel": "self"
+            },
+            {
+                "href": "%(compute_endpoint)s/servers/%(uuid)s",
+                "rel": "bookmark"
+            }
+        ],
+        "security_groups": [
+            {
+                "name": "default"
+            }
+        ]
+    }
+}

nova/tests/functional/api_sample_tests/api_samples/servers/v2.100/server-get-resp.json.tpl

@@ -0,0 +1,99 @@
+
+{
+    "server": {
+        "accessIPv4": "%(access_ip_v4)s",
+        "accessIPv6": "%(access_ip_v6)s",
+        "addresses": {
+            "private": [
+                {
+                    "addr": "%(ip)s",
+                    "OS-EXT-IPS-MAC:mac_addr": "00:0c:29:0d:11:74",
+                    "OS-EXT-IPS:type": "fixed",
+                    "version": 4
+                }
+            ]
+        },
+        "created": "%(isotime)s",
+        "description": null,
+        "locked": false,
+        "locked_reason": null,
+        "flavor": {
+            "disk": 1,
+            "ephemeral": 0,
+            "extra_specs": {},
+            "original_name": "m1.tiny",
+            "ram": 512,
+            "swap": 0,
+            "vcpus": 1
+        },
+        "hostId": "%(hostid)s",
+        "id": "%(id)s",
+        "image": {
+            "id": "%(uuid)s",
+            "links": [
+                {
+                    "href": "%(compute_endpoint)s/images/%(uuid)s",
+                    "rel": "bookmark"
+                }
+            ],
+            "properties": {
+                "architecture": "x86_64",
+                "auto_disk_config": "True",
+                "base_image_ref": "%(uuid)s",
+                "container_format": "ova",
+                "disk_format": "vhd",
+                "kernel_id": "nokernel",
+                "min_disk": "1",
+                "min_ram": "0",
+                "ramdisk_id": "nokernel"
+            }
+        },
+        "key_name": null,
+        "links": [
+            {
+                "href": "%(versioned_compute_endpoint)s/servers/%(uuid)s",
+                "rel": "self"
+            },
+            {
+                "href": "%(compute_endpoint)s/servers/%(uuid)s",
+                "rel": "bookmark"
+            }
+        ],
+        "metadata": {
+            "My Server Name": "Apache1"
+        },
+        "name": "new-server-test",
+        "config_drive": "%(cdrive)s",
+        "OS-DCF:diskConfig": "AUTO",
+        "OS-EXT-AZ:availability_zone": "us-west",
+        "OS-EXT-SRV-ATTR:hostname": "%(hostname)s",
+        "OS-EXT-STS:power_state": 1,
+        "OS-EXT-STS:task_state": null,
+        "OS-EXT-STS:vm_state": "active",
+        "os-extended-volumes:volumes_attached": [
+            {"id": "volume_id1", "delete_on_termination": false},
+            {"id": "volume_id2", "delete_on_termination": false}
+        ],
+        "OS-SRV-USG:launched_at": "%(strtime)s",
+        "OS-SRV-USG:terminated_at": null,
+        "pinned_availability_zone": "us-west",
+        "progress": 0,
+        "scheduler_hints": {
+            "same_host": [
+                "48e6a9f6-30af-47e0-bc04-acaed113bb4e"
+            ]
+        },
+        "security_groups": [
+            {
+                "name": "default"
+            }
+        ],
+        "server_groups": [],
+        "status": "ACTIVE",
+        "tags": [],
+        "tenant_id": "6f70656e737461636b20342065766572",
+        "trusted_image_certificates": null,
+        "updated": "%(isotime)s",
+        "user_id": "fake"
+    }
+}

nova/tests/functional/api_sample_tests/api_samples/servers/v2.100/server-list-resp.json.tpl

@@ -0,0 +1,25 @@
+{
+    "servers": [
+        {
+            "id": "%(id)s",
+            "links": [
+                {
+                    "href": "%(versioned_compute_endpoint)s/servers/%(id)s",
+                    "rel": "self"
+                },
+                {
+                    "href": "%(compute_endpoint)s/servers/%(id)s",
+                    "rel": "bookmark"
+                }
+            ],
+            "name": "new-server-test"
+        }
+    ],
+    "servers_links": [
+        {
+            "href": "%(versioned_compute_endpoint)s/servers?limit=1&marker=%(id)s",
+            "rel": "next"
+        }
+    ]
+}
+

nova/tests/functional/api_sample_tests/api_samples/servers/v2.100/server-update-req.json.tpl

@@ -0,0 +1,8 @@
+{
+    "server": {
+        "accessIPv4": "%(access_ip_v4)s",
+        "accessIPv6": "%(access_ip_v6)s",
+        "OS-DCF:diskConfig": "AUTO",
+        "hostname": "new-server-hostname.example.com"
+    }
+}

nova/tests/functional/api_sample_tests/api_samples/servers/v2.100/server-update-resp.json.tpl

@@ -0,0 +1,95 @@
+{
+    "server": {
+        "accessIPv4": "%(access_ip_v4)s",
+        "accessIPv6": "%(access_ip_v6)s",
+        "addresses": {
+            "private": [
+                {
+                    "addr": "%(ip)s",
+                    "OS-EXT-IPS-MAC:mac_addr": "00:0c:29:0d:11:74",
+                    "OS-EXT-IPS:type": "fixed",
+                    "version": 4
+                }
+            ]
+        },
+        "created": "%(isotime)s",
+        "description": null,
+        "locked": false,
+        "locked_reason": null,
+        "flavor": {
+            "disk": 1,
+            "ephemeral": 0,
+            "extra_specs": {},
+            "original_name": "m1.tiny",
+            "ram": 512,
+            "swap": 0,
+            "vcpus": 1
+        },
+        "hostId": "%(hostid)s",
+        "id": "%(id)s",
+        "image": {
+            "id": "%(uuid)s",
+            "links": [
+                {
+                    "href": "%(compute_endpoint)s/images/%(uuid)s",
+                    "rel": "bookmark"
+                }
+            ],
+            "properties": {
+                "architecture": "x86_64",
+                "auto_disk_config": "True",
+                "base_image_ref": "%(uuid)s",
+                "container_format": "ova",
+                "disk_format": "vhd",
+                "kernel_id": "nokernel",
+                "min_disk": "1",
+                "min_ram": "0",
+                "ramdisk_id": "nokernel"
+            }
+        },
+        "key_name": null,
+        "links": [
+            {
+                "href": "%(versioned_compute_endpoint)s/servers/%(uuid)s",
+                "rel": "self"
+            },
+            {
+                "href": "%(compute_endpoint)s/servers/%(uuid)s",
+                "rel": "bookmark"
+            }
+        ],
+        "metadata": {
+            "My Server Name": "Apache1"
+        },
+        "name": "new-server-test",
+        "config_drive": "",
+        "OS-DCF:diskConfig": "AUTO",
+        "OS-EXT-AZ:availability_zone": "us-west",
+        "OS-EXT-SRV-ATTR:hostname": "new-server-hostname.example.com",
+        "OS-EXT-STS:power_state": 1,
+        "OS-EXT-STS:task_state": null,
+        "OS-EXT-STS:vm_state": "active",
+        "os-extended-volumes:volumes_attached": [],
+        "OS-SRV-USG:launched_at": "%(strtime)s",
+        "OS-SRV-USG:terminated_at": null,
+        "pinned_availability_zone": "us-west",
+        "progress": 0,
+        "scheduler_hints": {
+            "same_host": [
+                "48e6a9f6-30af-47e0-bc04-acaed113bb4e"
+            ]
+        },
+        "security_groups": [
+            {
+                "name": "default"
+            }
+        ],
+        "server_groups": [],
+        "status": "ACTIVE",
+        "tags": [],
+        "tenant_id": "6f70656e737461636b20342065766572",
+        "trusted_image_certificates": null,
+        "updated": "%(isotime)s",
+        "user_id": "fake"
+    }
+}

nova/tests/functional/api_sample_tests/api_samples/servers/v2.100/servers-details-resp.json.tpl

@@ -0,0 +1,106 @@
+
+{
+    "servers": [
+        {
+            "accessIPv4": "%(access_ip_v4)s",
+            "accessIPv6": "%(access_ip_v6)s",
+            "addresses": {
+                "private": [
+                    {
+                        "addr": "%(ip)s",
+                        "OS-EXT-IPS-MAC:mac_addr": "00:0c:29:0d:11:74",
+                        "OS-EXT-IPS:type": "fixed",
+                        "version": 4
+                    }
+                ]
+            },
+            "created": "%(isotime)s",
+            "description": "",
+            "flavor": {
+                "disk": 1,
+                "ephemeral": 0,
+                "extra_specs": {},
+                "original_name": "m1.tiny",
+                "ram": 512,
+                "swap": 0,
+                "vcpus": 1
+            },
+            "hostId": "%(hostid)s",
+            "id": "%(id)s",
+            "image": {
+                "id": "%(uuid)s",
+                "links": [
+                    {
+                        "href": "%(compute_endpoint)s/images/%(uuid)s",
+                        "rel": "bookmark"
+                    }
+                ],
+                "properties": {
+                    "architecture": "x86_64",
+                    "auto_disk_config": "True",
+                    "base_image_ref": "%(uuid)s",
+                    "container_format": "ova",
+                    "disk_format": "vhd",
+                    "kernel_id": "nokernel",
+                    "min_disk": "1",
+                    "min_ram": "0",
+                    "ramdisk_id": "nokernel"
+                }
+            },
+            "key_name": null,
+            "links": [
+                {
+                    "href": "%(versioned_compute_endpoint)s/servers/%(uuid)s",
+                    "rel": "self"
+                },
+                {
+                    "href": "%(compute_endpoint)s/servers/%(id)s",
+                    "rel": "bookmark"
+                }
+            ],
+            "metadata": {
+                "My Server Name": "Apache1"
+            },
+            "name": "new-server-test",
+            "config_drive": "%(cdrive)s",
+            "locked": false,
+            "locked_reason": "",
+            "OS-DCF:diskConfig": "AUTO",
+            "OS-EXT-AZ:availability_zone": "us-west",
+            "OS-EXT-SRV-ATTR:hostname": "new-server-test",
+            "OS-EXT-STS:power_state": 1,
+            "OS-EXT-STS:task_state": null,
+            "OS-EXT-STS:vm_state": "active",
+            "os-extended-volumes:volumes_attached": [
+                {"id": "volume_id1", "delete_on_termination": false},
+                {"id": "volume_id2", "delete_on_termination": false}
+            ],
+            "OS-SRV-USG:launched_at": "%(strtime)s",
+            "OS-SRV-USG:terminated_at": null,
+            "pinned_availability_zone": "us-west",
+            "progress": 0,
+            "scheduler_hints": {
+                "same_host": [
+                    "48e6a9f6-30af-47e0-bc04-acaed113bb4e"
+                ]
+            },
+            "security_groups": [
+                {
+                    "name": "default"
+                }
+            ],
+            "status": "ACTIVE",
+            "tags": [],
+            "tenant_id": "6f70656e737461636b20342065766572",
+            "trusted_image_certificates": null,
+            "updated": "%(isotime)s",
+            "user_id": "fake"
+        }
+    ],
+    "servers_links": [
+        {
+            "href": "%(versioned_compute_endpoint)s/servers/detail?limit=1&marker=%(id)s",
+            "rel": "next"
+        }
+    ]
+}

nova/tests/functional/api_sample_tests/api_samples/servers/v2.100/servers-list-resp.json.tpl

@@ -0,0 +1,24 @@
+{
+    "servers": [
+        {
+            "id": "%(id)s",
+            "links": [
+                {
+                    "href": "%(versioned_compute_endpoint)s/servers/%(id)s",
+                    "rel": "self"
+                },
+                {
+                    "href": "%(compute_endpoint)s/servers/%(id)s",
+                    "rel": "bookmark"
+                }
+            ],
+            "name": "new-server-test"
+        }
+    ],
+    "servers_links": [
+        {
+            "href": "%(versioned_compute_endpoint)s/servers?limit=1&marker=%(id)s",
+            "rel": "next"
+        }
+    ]
+}

nova/tests/functional/api_sample_tests/test_servers.py

@@ -637,6 +637,47 @@ class ServerSampleJson298Test(ServersSampleJsonTest):
     ADMIN_API = False
 
 
+class ServersSampleJson2100Test(ServersSampleJsonTest):
+    microversion = '2.100'
+    scenarios = [('v2_100', {'api_major_version': 'v2.1'})]
+    ADMIN_API = False
+    use_common_server_post = False
+
+    def test_server_rebuild(self):
+        uuid = self._post_server(
+            use_common_server_api_samples=self.use_common_server_post
+        )
+        params = {
+            'uuid': self.glance.auto_disk_config_enabled_image['id'],
+            'name': 'foobar',
+            'pass': 'seekr3t',
+            'hostid': '[a-f0-9]+',
+            'access_ip_v4': '1.2.3.4',
+            'access_ip_v6': '80fe::',
+            'hostname': 'updated-hostname.example.com',
+        }
+
+        resp = self._do_post(
+            'servers/%s/action' % uuid,
+            'server-action-rebuild',
+            params,
+        )
+        subs = params.copy()
+        del subs['uuid']
+        self._verify_response('server-action-rebuild-resp', subs, resp, 202)
+
+    def test_update_server(self):
+        uuid = self._post_server(
+            use_common_server_api_samples=self.use_common_server_post)
+        subs = {}
+        subs['hostid'] = '[a-f0-9]+'
+        subs['access_ip_v4'] = '1.2.3.4'
+        subs['access_ip_v6'] = '80fe::'
+        response = self._do_put('servers/%s' % uuid,
+                                'server-update-req', subs)
+        self._verify_response('server-update-resp', subs, response, 200)
+
+
 class ServersUpdateSampleJsonTest(ServersSampleBase):
 
     # Many of the 'os_compute_api:servers:*' policies are admin-only, and we

nova/tests/unit/api/openstack/compute/test_servers.py

@@ -69,6 +69,7 @@ from nova.tests.unit.api.openstack import fakes
 from nova.tests.unit import fake_block_device
 from nova.tests.unit import fake_flavor
 from nova.tests.unit import fake_instance
+from nova.tests.unit import fake_request_spec
 from nova.tests.unit import matchers
 from nova import utils as nova_utils
 
@@ -8469,6 +8470,65 @@ class ServersViewBuilderTestV296(_ServersViewBuilderTest):
                           req, self.instances, False)
 
 
+class ServersViewBuilderTestV2100(_ServersViewBuilderTest):
+    """Server ViewBuilder test for microversion 2.100
+
+    The intent is simply to verify that when showing server details
+    after microversion 2.100 the response will always have a dict for
+    scheduler_hints.
+    """
+
+    def setUp(self):
+        super(ServersViewBuilderTestV2100, self).setUp()
+        self.view_builder = views.servers.ViewBuilder()
+        self.ctxt = context.RequestContext('fake', self.project_id)
+        self.request.api_version_request = (
+            api_version_request.APIVersionRequest('2.100'))
+
+    @mock.patch('nova.objects.RequestSpec.get_by_instance_uuid')
+    def test_build_server_detail_v2100(self, mock_get_req_spec):
+        mock_get_req_spec.return_value = fake_request_spec.fake_spec_obj()
+        expected_hints = {'hint': ['over-there']}
+
+        output = self.view_builder.show(self.request, self.instance)
+
+        self.assertIn('scheduler_hints', output['server'].keys())
+        self.assertThat(output['server']['scheduler_hints'],
+                        matchers.DictMatches(expected_hints))
+        exp_call = mock.call(
+            self.request.environ['nova.context'], self.instance.uuid)
+        mock_get_req_spec.assert_has_calls([exp_call, exp_call])
+
+    @mock.patch('nova.objects.RequestSpec.get_by_instance_uuid')
+    def test_build_server_detail_v2100_no_spec(self, mock_get_req_spec):
+        mock_get_req_spec.side_effect = exception.RequestSpecNotFound(
+            instance_uuid='foo')
+        expected_hints = {}
+
+        output = self.view_builder.show(self.request, self.instance)
+
+        self.assertIn('scheduler_hints', output['server'].keys())
+        self.assertThat(output['server']['scheduler_hints'],
+                        matchers.DictMatches(expected_hints))
+        exp_call = mock.call(
+            self.request.environ['nova.context'], self.instance.uuid)
+        mock_get_req_spec.assert_has_calls([exp_call, exp_call])
+
+    @mock.patch('nova.objects.RequestSpec.get_by_instance_uuid')
+    def test_build_server_detail_v299_no_hints(self, mock_get_req_spec):
+        # req_spec is retrieved since 2.96, but no scheduler_hints
+        # should be returned
+        self.request.api_version_request = (
+            api_version_request.APIVersionRequest('2.99'))
+        mock_get_req_spec.return_value = fake_request_spec.fake_spec_obj()
+
+        output = self.view_builder.show(self.request, self.instance)
+
+        self.assertNotIn('scheduler_hints', output['server'].keys())
+        mock_get_req_spec.assert_called_once_with(
+            self.request.environ['nova.context'], self.instance.uuid)
+
+
 class ServersActionsJsonTestV239(test.NoDBTestCase):
 
     def setUp(self):

releasenotes/notes/bp-show-sched-hints-server-details-22bc15d5ea81e43a.yaml

@@ -0,0 +1,7 @@
+---
+features:
+  - |
+    A new microversion has been added that allows users to retrieve
+    server's associated scheduler hints in ``GET /servers/{server_id}``,
+    ``GET /servers/detail``, ``PUT /servers/{server_id}`` and
+    ``POST /server/{server_id}/action`` (rebuild) responses.