Kubernetes: Setup Flannel High Availability

kubernetes HA Config Setting

Flannel

[Unit]
Description=Flanneld
Documentation=https://github.com/coreos/flannel
After=network.target
Before=docker.service

[Service]
User=root
ExecStart=/opt/bin/flanneld \
  --etcd-endpoints="http://192.168.51.140:2379,http://192.168.51.145:2379" \
  --iface=192.168.51.149 \
  --ip-masq
Restart=on-failure
Type=notify
LimitNOFILE=65536

here we set

 --etcd-endpoints="http://192.168.51.140:2379,http://192.168.51.145:2379"

with multiple endpoint

It works

Kubelet

[Unit]
Description=Kubernetes Kubelet
After=docker.service
Requires=docker.service

[Service]
ExecStart=/opt/bin/kubelet \
  --hostname-override=k8stargetnode \
  --api-servers="http://192.168.51.139:8080, http://192.168.51.145:8080" \
  --register-node=true \
  --logtostderr=false \
  --log-dir="/var/log/kubernetes" \
  --v=6 \
  --cluster_dns=172.18.0.5 \
  --cluster_domain=cluster.local
Restart=on-failure
KillMode=process

[Install]
WantedBy=multi-user.target

--api-servers="http://192.168.51.139:8080, http://192.168.51.145:8080" \

With error message

E0929 09:44:45.084951   58581 reflector.go:190] k8s.io/kubernetes/pkg/kubelet/config/apiserver.go:46: Failed to list *v1.Pod: Get http://192.168.51.139:8080/api/v1/pods?fieldSelector=spec.nodeName%3Dk8stargetnode&resourceVersion=0: dial tcp 192.168.51.139:8080: getsockopt: no route to host

It Failed, it always get first element.

Kube-proxy

With Error Message

E0929 09:40:44.597567   58456 reflector.go:201] k8s.io/kubernetes/pkg/proxy/config/api.go:49: Failed to list *api.Endpoints: Get http://192.168.51.139:8080,http/192.168.51.145:8080/api/v1/endpoints?resourceVersion=0: dial tcp: unknown port tcp/8080,http

It Failed

Result

An loadbalancer service is need for build k8s(kube-proxy, kubelet) for minion, but flannel can insert multiple address without needing loadbalancer.