Set the node_id param as a required property

The node_id property is a required property to perform the re-assigning
a node with a given ID from one cluster to another.

Change-Id: I2442442260f19833db239b01856d0ff4f63ecfbb
Closes-Bug: #1483239

cluster_upgrade/tests/test_handlers.py

@@ -163,3 +163,23 @@ class TestNodeReassignHandler(base.BaseIntegrationTest):
         self.assertEqual("Node {0} is already assigned to cluster {1}".
                          format(node_id, cluster_id),
                          resp.json_body['message'])
+
+    def test_node_reassign_handler_with_empty_data(self):
+        cluster = self.env.create_cluster(api=False)
+        resp = self.app.post(
+            reverse('NodeReassignHandler',
+                    kwargs={'cluster_id': cluster.id}),
+            "{}",
+            headers=self.default_headers,
+            expect_errors=True)
+        self.assertEqual(400, resp.status_code)
+
+    def test_node_reassign_handler_with_empty_body(self):
+        cluster = self.env.create_cluster(api=False)
+        resp = self.app.post(
+            reverse('NodeReassignHandler',
+                    kwargs={'cluster_id': cluster.id}),
+            "",
+            headers=self.default_headers,
+            expect_errors=True)
+        self.assertEqual(400, resp.status_code)

cluster_upgrade/tests/test_validators.py

@@ -121,3 +121,21 @@ class TestNodeReassignValidator(base.BaseTestCase):
         cluster = mock.Mock(id=42)
         with self.assertRaises(errors.InvalidData):
             self.validator.validate_node_cluster(node, cluster)
+
+    def test_validate_empty_data(self):
+        cluster = self.env.create_cluster(api=False)
+        node = self.env.create_node(cluster_id=cluster.id,
+                                    roles=["compute"],
+                                    status="ready")
+        msg = "^'node_id' is a required property"
+        with self.assertRaisesRegexp(errors.InvalidData, msg):
+            self.validator.validate("{}", node)
+
+    def test_validate_empty_body(self):
+        cluster = self.env.create_cluster(api=False)
+        node = self.env.create_node(cluster_id=cluster.id,
+                                    roles=["compute"],
+                                    status="ready")
+        msg = "^Empty request received$"
+        with self.assertRaisesRegexp(errors.InvalidData, msg):
+            self.validator.validate("", node)

cluster_upgrade/validators.py

@@ -93,6 +93,7 @@ class NodeReassignValidator(base.BasicValidator):
         "properties": {
             "node_id": {"type": "number"},
         },
+        "required": ["node_id"],
     }
 
     @classmethod