Add host show api

Add host show api.
I cannot bump the api version to 1.5 as the unit test fail. seem
pecan check the request version to all controller function which
lead to unit test fail.

Change-Id: I4b6afbe3f8126fea5323e5905366955e5b106b93
Partially-Implements: blueprint show-container-engine-info

api-ref/source/hosts.inc

@@ -43,3 +43,44 @@ Response Example
 
 .. literalinclude:: samples/host-get-all-resp.json
    :language: javascript
+
+Show details of a host
+===========================
+
+.. rest_method:: GET /v1/hosts/{host_ident}
+
+Get all information of a host in Zun.
+
+Response Codes
+--------------
+
+.. rest_status_code:: success status.yaml
+
+   - 200
+
+.. rest_status_code:: error status.yaml
+
+   - 401
+   - 403
+   - 404
+
+Request
+-------
+
+.. rest_parameters:: parameters.yaml
+
+  - host_ident: host_ident
+
+Response
+--------
+
+.. rest_parameters:: parameters.yaml
+
+  - uuid: uuid
+  - hostname: hostname
+
+Response Example
+----------------
+
+.. literalinclude:: samples/host-get-resp.json
+   :language: javascript

api-ref/source/samples/host-get-resp.json

@@ -0,0 +1,19 @@
+{
+    "hostname": "test",
+    "uuid": "d0405f06-101e-4340-8735-d1bf9fa8b8ad",
+    "links": [{
+        "href": "http://192.168.2.22:9517/v1/hosts/d0405f06-101e-4340-8735-d1bf9fa8b8ad",
+        "rel": "self"
+        },
+        {"href": "http://192.168.2.22:9517/hosts/d0405f06-101e-4340-8735-d1bf9fa8b8ad",
+         "rel": "bookmark"}
+    ],
+    "kernel_version": "3.10.0-123.el7.x86_64",
+    "labels": {"type": "test"},
+    "cpus": 48,
+    "mem_total": 128446,
+    "total_containers": 3,
+    "os_type": "linux",
+    "os": "CentOS Linux 7 (Core)",
+    "architecture": "x86_64"
+}

etc/zun/policy.json

@@ -40,5 +40,6 @@
     "zun-service:force_down": "rule:admin_api",
     "zun-service:get_all": "rule:admin_api",
 
-    "host:get_all": "rule:admin_api"
+    "host:get_all": "rule:admin_api",
+    "host:get": "rule:admin_api"
 }

zun/api/controllers/v1/hosts.py

@@ -11,6 +11,7 @@
 #    under the License.
 
 from oslo_log import log as logging
+from oslo_utils import uuidutils
 import pecan
 
 from zun.api.controllers import base
@@ -24,6 +25,25 @@ from zun import objects
 LOG = logging.getLogger(__name__)
 
 
+def _get_host(host_id):
+    host = None
+    if uuidutils.is_uuid_like(host_id):
+        host = objects.ComputeNode.get_by_uuid(pecan.request.context, host_id)
+    else:
+        host = objects.ComputeNode.get_by_hostname(pecan.request.context,
+                                                   host_id)
+    if not host:
+        pecan.abort(404, ('Not found; the host you requested '
+                          'does not exist.'))
+
+    return host
+
+
+def check_policy_on_host(host, action):
+    context = pecan.request.context
+    policy.enforce(context, action, host, action=action)
+
+
 class HostCollection(collection.Collection):
     """API representation of a collection of hosts."""
 
@@ -83,3 +103,16 @@ class HostController(base.Controller):
                                                  expand=expand,
                                                  sort_key=sort_key,
                                                  sort_dir=sort_dir)
+
+    @pecan.expose('json')
+    @base.Controller.api_version("1.4")
+    @exception.wrap_pecan_controller_exception
+    def get_one(self, host_id):
+        """Retrieve information about the given host.
+
+        :param host_ident: UUID or name of a host.
+        """
+        context = pecan.request.context
+        policy.enforce(context, "host:get", action="host:get")
+        host = _get_host(host_id)
+        return view.format_host(pecan.request.host_url, host)

zun/api/controllers/v1/views/hosts_view.py

@@ -21,7 +21,11 @@ _basic_keys = (
     'hostname',
     'mem_total',
     'cpus',
+    'total_containers',
+    'architecture',
+    'os_type',
     'os',
+    'kernel_version',
     'labels'
 )
 

zun/api/controllers/versions.py

@@ -36,7 +36,7 @@ REST_API_VERSION_HISTORY = """REST API Version History:
     * 1.1 - Initial version
     * 1.2 - Support user specify pre created networks
     * 1.3 - Add auto_remove to container
-    * 1.4 - Support list all container host
+    * 1.4 - Support list all container host and show a container host
 """
 
 BASE_VER = '1.1'

zun/api/rest_api_version_history.rst

@@ -48,3 +48,5 @@ user documentation.
 
   Add host list api.
   Users can use this api to list all the zun compute hosts.
+  Add get host api
+  Users can use this api to get details of a zun compute host.

zun/tests/unit/api/controllers/v1/test_hosts.py

@@ -33,7 +33,7 @@ class TestHostController(api_base.FunctionalTest):
 
         extra_environ = {'HTTP_ACCEPT': 'application/json'}
         headers = {'OpenStack-API-Version': 'container 1.4'}
-        response = self.app.get('/v1/hosts/', extra_environ=extra_environ,
+        response = self.app.get('/v1/hosts', extra_environ=extra_environ,
                                 headers=headers)
 
         mock_host_list.assert_called_once_with(mock.ANY,
@@ -59,7 +59,7 @@ class TestHostController(api_base.FunctionalTest):
         mock_host_list.return_value = host_list[-1:]
         extra_environ = {'HTTP_ACCEPT': 'application/json'}
         headers = {'OpenStack-API-Version': 'container 1.4'}
-        response = self.app.get('/v1/hosts/?limit=3&marker=%s'
+        response = self.app.get('/v1/hosts?limit=3&marker=%s'
                                 % host_list[2].uuid,
                                 extra_environ=extra_environ, headers=headers)
 
@@ -69,6 +69,25 @@ class TestHostController(api_base.FunctionalTest):
         self.assertEqual(host_list[-1].uuid,
                          actual_hosts[0].get('uuid'))
 
+    @patch('zun.objects.ComputeNode.get_by_uuid')
+    def test_get_one_host(self, mock_get_by_uuid):
+        test_host = utils.get_test_compute_node()
+        numat = numa.NUMATopology._from_dict(test_host['numa_topology'])
+        test_host['numa_topology'] = numat
+        test_host_obj = objects.ComputeNode(self.context, **test_host)
+        mock_get_by_uuid.return_value = test_host_obj
+        extra_environ = {'HTTP_ACCEPT': 'application/json'}
+        headers = {'OpenStack-API-Version': 'container 1.4'}
+        response = self.app.get('/v1/hosts/%s' % test_host['uuid'],
+                                extra_environ=extra_environ,
+                                headers=headers)
+        mock_get_by_uuid.assert_called_once_with(
+            mock.ANY,
+            test_host['uuid'])
+        self.assertEqual(200, response.status_int)
+        self.assertEqual(test_host['uuid'],
+                         response.json['uuid'])
+
 
 class TestHostEnforcement(api_base.FunctionalTest):
 
@@ -85,5 +104,12 @@ class TestHostEnforcement(api_base.FunctionalTest):
         extra_environ = {'HTTP_ACCEPT': 'application/json'}
         headers = {'OpenStack-API-Version': 'container 1.4'}
         self._common_policy_check(
-            'host:get_all', self.get_json, '/hosts/',
+            'host:get_all', self.get_json, '/hosts',
+            expect_errors=True, extra_environ=extra_environ, headers=headers)
+
+    def test_pollicy_disallow_get_one(self):
+        extra_environ = {'HTTP_ACCEPT': 'application/json'}
+        headers = {'OpenStack-API-Version': 'container 1.4'}
+        self._common_policy_check(
+            'host:get', self.get_json, '/hosts/%s' % '12345678',
             expect_errors=True, extra_environ=extra_environ, headers=headers)