Windows Kernel now exposes "Internal Load Balancing"
using VFP (Virtual Filtering Platform) part of Virtual Switch. An inbuild
windows service HNS (Host Networking Service) acts as interface to program
the VFP. VFP is synonymous to iptables in functionality. HNS uses json based
data as input.
With the help of the interface available in github.com/Microsoft/hcsshim,
these APIs are exposed to the world in github to program HNS and use
the feature.
*** More info about the changes in this PR ***
(1) For every endpoint available in the system, an HNS Endpoint is added
(1.a) for local endpoints, a local HNS Endpoint would already exist, as part of
container creation.
(1.b) For all remote endpoints, a remote HNS Endpoint is created via HNS
(2) For every Service, a HNS ILB LoadBalancer is added referring the endpoints
created in (1)
Sample Input to HNS:
{
"Policies": [
{
"ExternalPort": 80,
"InternalPort": 80,
"Protocol": 6,
"Type": "ELB",
"VIPs": [
"11.0.98.129"
]
}
],
"References": [
"/endpoints/ca8b877b-ab90-499a-bc0e-7d736c425632",
"/endpoints/ee0ef08b-8434-4f8b-b748-393884e77465"
]
}
(2-a) This is done for Cluster IP, LoadBalancer Ingress IP, NodePort, External IP
Following the regular service and endpoint updates,
the HNS is notified of the updates and the system is kept in sync.
Casey Callendrello