Skip to content

Latest commit

 

History

History
24 lines (18 loc) · 1.72 KB

ha-mode.md

File metadata and controls

24 lines (18 loc) · 1.72 KB
Raw

HA mode (internal loadbalancing)

K8s components require a loadbalancer to access the apiservers via a reverse proxy. Kubekey uses kube-vip and haproxy to provide internal ha mode.

haproxy

The way kubekey uses is referred to as localhost loadbalancing. The kubelet of each master node connects the local kube-apiserver, and the kubelet of each worker node connects the kube-apiserver via a local reverse proxy. Based on this, kubekey will deploy a haproxy-based proxy that resides on each worker node as the local reverse proxy.

Image

kube-vip

The load balancing is provided through IPVS (IP Virtual Server) and provides a Layer 4 (TCP-based) round-robin across all of the control plane nodes. By default, the load balancer will listen on the default port of 6443 as the Kubernetes API server. The IPVS virtual server lives in kernel space and doesn't create an "actual" service that listens on port 6443. This allows the kernel to parse packets before they're sent to an actual TCP port. Based on this, kubekey will deploy a static pod that resides on each control-plane node as the internal loadbalancing.

Image

Usage

Modify your configuration file and uncomment the item internalLoadbalancer:

controlPlaneEndpoint:
    internalLoadbalancer: haproxy #Internal loadbalancer for apiservers. Support: haproxy, kube-vip [Default: ""]
    
    domain: lb.kubesphere.local 
    address: "" # The IP address of your load balancer. If you use internalLoadblancer in "kube-vip" mode, a VIP is required here.
    port: 6443

Then whether you exec the command create cluster, add nodes or upgrade, kubekey will enable HA mode and deploy the interanl load balancer.