how to write a nova service?

1. openstack 的 service

2. 自定义自己的service

3. extend API

https://www.ibm.com/developerworks/community/blogs/e93514d3-c4f0-4aa0-8844-497f370090f5/entry/openstack_nova_api?lang=zh

https://wiki.openstack.org/wiki/WritingRequestExtensions

 http://stephanfr.com/2013/04/07/creating-an-openstack-keystone-helloworld-extension/

http://www.cnblogs.com/willier/archive/2013/05/22/3092961.html

4. how to use the periodic task  in self define service in openstack framework.

5. how to write nova-client to call the extend API

6. how to write CLI to call the extend API