Enable parameter check before node composition

This patch enabled check for "name" field in request body before
node composition, raise BadRequest exception if if don't exits.
Changed "description" to optional, and will set it to empty string
if it don't exist.

Change-Id: Ib3624ad85e12823c5f6fd6321d3161b88a7b6ecf
Closes-Bug: #1677046

api-ref/source/parameters.yaml

@@ -217,7 +217,7 @@ node_request_description:
    description: |
      A description for a new composed node
    in: body
-   required: tree
+   required: false
    type: string
 node_request_name:
   description: |

valence/controller/nodes.py

@@ -77,8 +77,12 @@ class Node(object):
                 "processor": {}
             }
 
+        if not("name" in request_body and request_body["name"].strip()):
+            raise exception.BadRequest(
+                detail="Please specify a name of the node to compose")
         name = request_body["name"]
-        description = request_body["description"]
+        # "description" is optional
+        description = request_body.get("description", "")
 
         compose_request = cls._create_compose_request(name,
                                                       description,

valence/tests/unit/controller/test_nodes.py

@@ -73,6 +73,14 @@ class TestAPINodes(unittest.TestCase):
                                                     requirements)
         self.assertEqual(expected, result)
 
+    def test_compose_node_with_wrong_parameters(self):
+        """Test compose node with no name input"""
+        with self.assertRaises(exception.BadRequest) as context:
+            nodes.Node.compose_node({"no_name": "fake_value"})
+
+        self.assertTrue("Please specify a name of the node to compose"
+                        in context.exception.detail)
+
     @mock.patch("valence.db.api.Connection.create_composed_node")
     @mock.patch("valence.common.utils.generate_uuid")
     @mock.patch("valence.controller.nodes.Node.list_composed_nodes")