Add node enquiry API

Provide an API endpoint in Drydock to query
the state of nodes in the downstream MAAS
service.

Change-Id: I7cf4f3cf81e51ef5dc604c778d6a03d7f1208ffa

drydock_provisioner/control/api.py

@@ -16,6 +16,7 @@ import falcon
 from .designs import *
 from .tasks import *
 from .bootdata import *
+from .nodes import NodesResource
 
 from .base import DrydockRequest
 from .middleware import AuthMiddleware, ContextMiddleware, LoggingMiddleware
@@ -59,7 +60,10 @@ def start_api(state_manager=None, ingester=None, orchestrator=None):
 
         # API for nodes to discover their bootdata during curtin install
         ('/bootdata/{hostname}/{data_key}', BootdataResource(
-            state_manager=state_manager, orchestrator=orchestrator))
+            state_manager=state_manager, orchestrator=orchestrator)),
+
+        # API to list current MaaS nodes
+        ('/nodes', NodesResource()),
     ]
 
     for path, res in v1_0_routes:

drydock_provisioner/control/nodes.py

@@ -0,0 +1,48 @@
+# Copyright 2017 AT&T Intellectual Property.  All other rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+import falcon
+import json
+
+from drydock_provisioner import policy
+from drydock_provisioner import config
+
+from drydock_provisioner.drivers.node.maasdriver.api_client import MaasRequestFactory
+from drydock_provisioner.drivers.node.maasdriver.models.machine import Machines
+
+from .base import BaseResource
+
+
+class NodesResource(BaseResource):
+    def __init__(self):
+        super().__init__()
+
+    @policy.ApiEnforcer('physical_provisioner:read_data')
+    def on_get(self, req, resp):
+        try:
+            maas_client = MaasRequestFactory(config.config_mgr.conf.maasdriver.maas_api_url,
+                                             config.config_mgr.conf.maasdriver.maas_api_key)
+
+            machine_list = Machines(maas_client)
+            machine_list.refresh()
+
+            node_view = list()
+            for m in machine_list:
+                node_view.append(dict(hostname=m.hostname, memory=m.memory, cpu_count=m.cpu_count, status_name=m.status_name, boot_mac=m.boot_mac))
+
+            resp.body = json.dumps(node_view)
+            resp.status = falcon.HTTP_200
+        except Exception as ex:
+            self.error(req.context, "Unknown error: %s" % str(ex), exc_info=ex)
+            self.return_error(
+                resp, falcon.HTTP_500, message="Unknown error", retry=False)