This commit rename the var name, text appearance, and swagger of "master" role
to "maintainer" role.
It only covers backend code.
Signed-off-by: Daniel Jiang <jiangd@vmware.com>
- define instance's api
- define extension models for api
- implement preheat controller
- implement preheat manager
- most code are picked up from the original P2P feat branch
Signed-off-by: fanjiankong <fanjiankong@tencent.com>