hype-v上centos7部署高可用kubernetes集群实践

概述

在上一篇中已经实践了 非高可用的bubernetes集群的实践

普通的k8s集群当work node 故障时是高可用的,但是master node故障时将会发生灾难,因为k8s api server不可用

会导致整个集群群龙无首

所以本篇将在上篇的基础上扩展高可用的k8s 集群

其原理是将所有node对master的api请求通过负载均衡(haproxy)指向虚拟ip(keepalived)

而此虚拟ip由所有master节点通过优先级选举

在上篇中我已经做好了k8s环境的基础虚拟机镜像文件,所以我这篇将从恢复虚拟机镜像文件为起点

虚拟ip  192.168.1.200   

m1　　192.168.1.201

m2　　192.168.1.202

w1　　192.168.1.211

 

m1是matser node 1

w1是work node 1

命名自己按喜欢的来即可

在所有master节点上我需要做

1.修改host文件 加入hostname域名解析 

[root@m1 ~]# [root@m1 ~]# cat /etc/hosts
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
192.168.1.200 VIP
192.168.1.201 m1
192.168.1.202 m2
192.168.1.211 w1

 

2.修改hostname

[root@m1 ~]# hostnamectl set-hostname m1

需要登出后再登进才可以生效

3.修改静态ip

[root@m1 ~]# cat /etc/sysconfig/network-scripts/ifcfg-eth0
TYPE=Ethernet
PROXY_METHOD=none
BROWSER_ONLY=no
BOOTPROTO=static
DEFROUTE=yes
IPV4_FAILURE_FATAL=no
IPV6INIT=yes
IPV6_AUTOCONF=yes
IPV6_DEFROUTE=yes
IPV6_FAILURE_FATAL=no
IPV6_ADDR_GEN_MODE=stable-privacy
NAME=eth0
UUID=ea0a7d62-0d12-4fd6-897d-d7a87e031d6f
DEVICE=eth0
ONBOOT=yes

GATEWAY=192.168.1.1
IPADDR=192.168.1.201
NETMASK=255.255.255.0
DNS1=192.168.1.1
DNS2=8.8.8.8

 

4.安装配置keepalvied

yum install keepalived

[root@m1 ~]# cat /etc/keepalived/keepalived.conf
! Configuration File for keepalived

global_defs {
   notification_email {
        [email protected]
   }
   notification_email_from [email protected]
   smtp_server 127.0.0.1
   smtp_connect_timeout 30
   router_id LVS_1
}

vrrp_instance VI_1 {
    state MASTER
    interface eth0
    lvs_sync_daemon_inteface eth0
    virtual_router_id 79
    advert_int 1
    priority 100
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
      192.168.1.200
    }
}

优先级其他的matster节点逐渐下降 90 80 70 ...

192.168.1.200是上面规划好的虚拟ip

 

[root@m1 ~]# systemctl restart keepalived

[root@m1 ~]# systemctl enable keepalived

重启服务,开机自诩

 

5.安装配置haproxy

[root@m1 ~]# cat /etc/haproxy/haproxy.cfgfg
global
        chroot  /var/lib/haproxy
        daemon
        group haproxy
        user haproxy
        log 127.0.0.1:514 local0 warning
        pidfile /var/lib/haproxy.pid
        maxconn 20000
        spread-checks 3
        nbproc 8

defaults
        log     global
        mode    tcp
        retries 3
        option redispatch

listen https-apiserver
        bind *:8443
        mode tcp
        balance roundrobin
        timeout server 900s
        timeout connect 15s

        server m1 192.168.1.201:6443 check port 6443 inter 5000 fall 5
        server m2 192.168.1.202:6443 check port 6443 inter 5000 fall 5

所有master节点上配置一致的

 

[root@m1 ~]# systemctl start haproxy
[root@m1 ~]# systemctl enable haproxy

启动服务,开启自启

 

在第一个master节点上我需要做

1.配置kubeadm 初始化配置文件

kubeadm-init.yaml
apiVersion: kubeadm.k8s.io/v1beta2
kind: ClusterConfiguration
kubernetesVersion: v1.16.2
imageRepository: registry.cn-hangzhou.aliyuncs.com/google_containers
controlPlaneEndpoint: "192.168.1.200:8443" networking: serviceSubnet: "10.96.0.0/16" podSubnet: "192.168.0.0/16" dnsDomain: "cluster.local" 

192.168.1.200:8443是我们的虚拟ip ,master转发这个端口数据到负载均衡上再到某一个master的6443端口上

1.16.2是我现在在使用的kube三件的版本

192.168.0.0是我规划的pod子网段

 

2.初始化

kubeadm init --config=kubeadm-init.yaml --upload-certs

成功后会生成两个join的指令,  第一个是master节点用的加入   第二个是工作节点上的加入

Your Kubernetes control-plane has initialized successfully!

To start using your cluster, you need to run the following as a regular user:

  mkdir -p $HOME/.kube
  sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
  sudo chown $(id -u):$(id -g) $HOME/.kube/config

You should now deploy a pod network to the cluster.
Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at:
  https://kubernetes.io/docs/concepts/cluster-administration/addons/

You can now join any number of the control-plane node running the following command on each as root:

  kubeadm join 192.168.1.200:6443 --token 15wggu.lostbmuhkconfve8 \
    --discovery-token-ca-cert-hash sha256:60bad8d33b8bea0ce9820746453e5ff28f8faa522f97e1018f56824ed29cab89 \
    --control-plane --certificate-key 48b866c774671ede8d42b2188717d8e33e026d4fa7c1e9220a93e38a9bede443

Please note that the certificate-key gives access to cluster sensitive data, keep it secret!
As a safeguard, uploaded-certs will be deleted in two hours; If necessary, you can use
"kubeadm init phase upload-certs --upload-certs" to reload certs afterward.

Then you can join any number of worker nodes by running the following on each as root:

kubeadm join 192.168.1.200:6443 --token 15wggu.lostbmuhkconfve8 \
    --discovery-token-ca-cert-hash sha256:60bad8d33b8bea0ce9820746453e5ff28f8faa522f97e1018f56824ed29cab89

 密钥如果过期重新上传

sudo kubeadm init phase upload-certs --upload-certs

3.安装网络策略

最新参阅https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/create-cluster-kubeadm/#pod-network

[root@m1 ~]# wget https://kuboard.cn/install-script/calico/calico-3.9.2.yaml
#默认是192.168.0.0 ,pod子网不一样的要手动修改
[root@m1 ~]# kubectl apply -f calico-3.9.2.yaml

 

4.去污点

查看污点

[root@m1 ~]# kubectl describe node m1|grep -i taints
Taints: node-role.kubernetes.io/master:NoSchedule

删除默认的污点

[root@m1 ~]#  kubectl taint nodes m1 node-role.kubernetes.io/master-
node/m1 untainted

所有master都加入集群后,删除所有master的污点
kubectl taint nodes --all node-role.kubernetes.io/master-

 在其他master 节点上我需要做

执行

kubeadm join 192.168.1.200:6443 --token 15wggu.lostbmuhkconfve8 \
    --discovery-token-ca-cert-hash sha256:60bad8d33b8bea0ce9820746453e5ff28f8faa522f97e1018f56824ed29cab89 \
    --control-plane --certificate-key 48b866c774671ede8d42b2188717d8e33e026d4fa7c1e9220a93e38a9bede443

去污点同上

在其他work 节点上我需要做

kubeadm join 192.168.1.200:6443 --token 15wggu.lostbmuhkconfve8 \
    --discovery-token-ca-cert-hash sha256:60bad8d33b8bea0ce9820746453e5ff28f8faa522f97e1018f56824ed29cab89

在各个master节点上都可以执行 kubectl get node 等 master的指令了

 

最后

由于本人使用笔记本(低压)上的虚拟机实践,所以只部署了2个master node,

建议最少三个master节点,并且主机点上不应该去污点