address minor bugs in nxos shared module

This addresses two issues with the nxos shared module.  The first issue is
argument precedence checking.  The module should prefer explicit arguments
over arguments passed vi the provider.  This is now fixed to honor that
precedence.  The second issue is collecting output from nxapi and returning
the response.  Prior to this change the entire json structure was returned.
Now just the output is returned to align it better with cli based output

lib/ansible/module_utils/nxos.py

@@ -23,7 +23,7 @@ NET_COMMON_ARGS = dict(
     port=dict(type='int'),
     username=dict(required=True),
     password=dict(no_log=True),
-    transport=dict(choices=['cli', 'nxapi']),
+    transport=dict(default='cli', choices=['cli', 'nxapi']),
     use_ssl=dict(default=False, type='bool'),
     provider=dict()
 )
@@ -107,11 +107,24 @@ class Nxapi(object):
             self.module.fail_json(**headers)
 
         response = self.module.from_json(response.read())
-        if 'error' in response:
-            err = response['error']
-            self.module.fail_json(msg='json-rpc error % ' % str(err))
+        result = list()
+
+        output = response['ins_api']['outputs']['output']
+        if isinstance(output, list):
+            for item in response['ins_api']['outputs']['output']:
+                if item['code'] != '200':
+                    self.module.fail_json(msg=item['msg'], command=item['input'],
+                            code=item['code'])
+                else:
+                    result.append(item['body'])
+        elif output['code'] != '200':
+            self.module.fail_json(msg=item['msg'], command=item['input'],
+                    code=item['code'])
+        else:
+            result.append(output['body'])
 
-        return response
+
+        return result
 
 class Cli(object):
 
@@ -150,6 +163,7 @@ class NetworkModule(AnsibleModule):
         provider = params.get('provider') or dict()
         for key, value in provider.items():
             if key in NET_COMMON_ARGS.keys():
+                if not params.get(key) and value is not None:
                     params[key] = value
         return params
 
@@ -159,11 +173,9 @@ class NetworkModule(AnsibleModule):
         else:
             self.connection = Cli(self)
 
-        try:
         self.connection.connect()
+        if self.params['transport'] == 'cli':
             self.execute('terminal length 0')
-        except Exception, exc:
-            self.fail_json(msg=exc.message)
 
     def configure(self, commands):
         commands = to_list(commands)
@@ -176,10 +188,7 @@ class NetworkModule(AnsibleModule):
         return responses
 
     def execute(self, commands, **kwargs):
-        try:
         return self.connection.send(commands, **kwargs)
-        except Exception, exc:
-            self.fail_json(msg=exc.message)
 
     def disconnect(self):
         self.connection.close()
@@ -194,10 +203,7 @@ class NetworkModule(AnsibleModule):
         if self.params['transport'] == 'cli':
             return self.execute(cmd)[0]
         else:
-            resp = self.execute(cmd)
-            if not resp.get('ins_api').get('outputs').get('output').get('body'):
-                self.fail_json(msg="Unrecognized response: %s" % str(resp))
-            return resp['ins_api']['outputs']['output']['body']
+            return self.execute(cmd)
 
 def get_module(**kwargs):
     """Return instance of NetworkModule