Add support for nic and az in cluster grow

Added support for the nic and az parameter in cluster grow for
mongodb.

Redis and cassandra already fully supported these fields.

Change-Id: If1cecbd0a893bb493187cdad0c563e6ea681d250
Closes-Bug: #1641675

releasenotes/notes/grow-cluster-nic-az-0e0fe4083666c300.yaml

@@ -0,0 +1,4 @@
+---
+fixes:
+  - Pass instance nic and az to cluster grow.  Add specific
+    Fix for mongodb to use the instance nic and az.

trove/cluster/models.py

@@ -298,6 +298,11 @@ class Cluster(object):
                         instance['volume_size'] = int(node['volume']['size'])
                     if 'modules' in node:
                         instance['modules'] = node['modules']
+                    if 'nics' in node:
+                        instance['nics'] = node['nics']
+                    if 'availability_zone' in node:
+                        instance['availability_zone'] = (
+                            node['availability_zone'])
                     instances.append(instance)
                 return self.grow(instances)
         elif action == 'shrink':

trove/common/strategies/cluster/experimental/mongodb/api.py

@@ -199,6 +199,8 @@ class MongoDbCluster(models.Cluster):
                                                     'query_router'])
         name = _check_option('name')
         related_to = _check_option('related_to')
+        nics = _check_option('nics')
+        availability_zone = _check_option('availability_zone')
 
         unused_keys = list(set(item.keys()).difference(set(used_keys)))
         if unused_keys:
@@ -214,6 +216,10 @@ class MongoDbCluster(models.Cluster):
             instance['name'] = name
         if related_to:
             instance['related_to'] = related_to
+        if nics:
+            instance['nics'] = nics
+        if availability_zone:
+            instance['availability_zone'] = availability_zone
         return instance
 
     def action(self, context, req, action, param):