Add a new config option, an example:
[kubernetes]
trusted_cidrs = 127.0.0.1/32,198.72.124.109/32
If trusted_cidrs is empty list, the local IP CIDR will be used.
The pod in qinling namespace can only be accessed by the CIDRs
configured.
Change-Id: Iecc34c1be16851cc53afe2fca94c2bbf0fdf7988
Story: 2004206
Task: 27715