搭建高可用k8s

搭建k8s高可用

高可用只针对于api-server，需要用到nginx + keepalived，nginx提供4层负载，keepalived提供vip(虚拟IP)

系统采用openEuler 22.03 LTS

1. 前期准备

因为机器内存只有16G，所有我采用3master + 1node

主机名	IP	VIP
master01	192.168.200.163	192.168.200.200
master02	192.168.200.164	192.168.200.200
master03	192.168.200.165	192.168.200.200
node	192.168.200.166

1.1 修改主机配置（所有节点操作）

1. 修改主机名
2. 关闭防火墙，selinux
3. 关闭swap
4. 配置时间同步

主机过多，我只写master01的操作

# 修改主机名
[root@localhost ~]# hostnamectl set-hostname master01
[root@localhost ~]# bash
# 关闭防火墙，selinux
[root@master01 ~]# systemctl disable --now firewalld
[root@master01 ~]# setenforce 0
[root@master01 ~]# sed -i s"/^SELINUX=.*/SELINUX=disabled/g" /etc/selinux/config
# 关闭swap
[root@master01 ~]# swapoff -a
# 配置时间同步
[root@master01 ~]# yum install chrony -y
[root@master01 ~]# chronyc sources

1.2 开启ipvs（所有节点）

[root@master01 ~]# cat > /etc/sysconfig/modules/ipvs.modules << END
> #!/bin/bash
> ipvs_modules="ip_vs ip_vs_lc ip_vs_wlc ip_vs_rr ip_vs_wrr ip_vs_lblc ip_vs_lblcr ip_vs_dh ip_vs_sh ip_vs_nq ip_vs_sed ip_vs_ftp nf_conntrack"
> for kernel_module in ${ipvs_modules};do
>   /sbin/modinfo -F filename ${kernel_module} > /dev/null 2>&1
>   if [ 0 -eq 0]; then
>   /sbin/modprobe ${kernel_module}
>   fi
> done
> END
[root@master01 ~]# chmod 755 /etc/sysconfig/modules/ipvs.modules 
[root@master01 ~]# bash /etc/sysconfig/modules/ipvs.modules

1.3 配置k8s yum源（所有节点）

# 直接到华为镜像站搜索kubernetes
[root@master01 ~]#  cat < /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://mirrors.huaweicloud.com/kubernetes/yum/repos/kubernetes-el7-$basearch
enabled=1
gpgcheck=1
repo_gpgcheck=0
gpgkey=https://mirrors.huaweicloud.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.huaweicloud.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF

使用欧拉的话需要将$basearch 改为自己的架构 x86_64

2. 安装docker（所有节点）

由于欧拉目前最高支持k8s的版本是1.23 ，所以需要安装docker

2.1 安装

[root@master01 ~]# yum install docker -y

2.2 修改docker配置

[root@master01 ~]# vim /etc/docker/daemon.json
{
        "exec-opts":["native.cgroupdriver=systemd"]
}

2.3 重启docker

[root@master01 ~]# systemctl daemon-reload
[root@master01 ~]# systemctl restart docker

3. 配置高可用(所有master节点)

3.1 安装软件包

[root@master01 ~]#  yum install nginx nginx-all-modules keepalived -y

3.2 配置nginx负载

在nginx的配置文件内加入一下内容

[root@master01 ~]# vim /etc/nginx/nginx.conf
user nginx;
worker_processes auto;
error_log /var/log/nginx/error.log;
pid /run/nginx.pid;
 
# Load dynamic modules. See /usr/share/doc/nginx/README.dynamic.
include /usr/share/nginx/modules/*.conf;
 
events {
    worker_connections 1024;
}
# 添加这一段，要写在http段之外，因为我们用的是四层负载，并不是七层负载
stream {
   upstream k8s-apiserver {
     server 192.168.200.163:6443;
     server 192.168.200.164:6443;
     server 192.168.200.165:6443;
   }
   server {
     listen 16443;
     proxy_pass k8s-apiserver;
   }
}
# 到这里结束
 
# 检测语法
[root@master01 ~]# nginx -t
nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: configuration file /etc/nginx/nginx.conf test is successful
 
# 重启
[root@master01 ~]# systemctl restart nginx

3.3 配置keepalived

# 备份原有配置
[root@master01 ~]# cp /etc/keepalived/keepalived.conf /etc/keepalived/keepalived.conf.bak
# 修改配置
[root@master01 ~]# vim /etc/keepalived/keepalived.conf 
global_defs {
    router_id master1
}
 
vrrp_instance Nginx {
    state MASTER           # 只有master01写MASTER，其他master写BACKUP
    interface ens33        # 写上网卡
    virtual_router_id 51
    priority 200           # 其他节点的值要低于这个,另外2个节点的值也不要一样
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 123
    }
    virtual_ipaddress {
        192.168.200.200     # 写VIP
    }
}
# 重启
[root@master01 ~]# systemctl restart keepalived.service

将原本的配置项都删除，写入这些内容

注意：只有master01的 state 是MASTER，其他2个节点应该写为BACKUP。且priority要低于master01

3.4 验证keepalived

# 查看master01的ens33
[root@master01 ~]# ip a show ens33
2: ens33:  mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 00:0c:29:8d:ce:8a brd ff:ff:ff:ff:ff:ff
    altname enp2s1
    inet 192.168.200.163/24 brd 192.168.200.255 scope global noprefixroute ens33
       valid_lft forever preferred_lft forever
    inet 192.168.200.200/32 scope global ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::ce91:fe4e:625d:6e32/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever

现在他有自己的iP和VIP

# 停掉keepalived
[root@master01 ~]# systemctl stop keepalived.service 
[root@master01 ~]# ip a show ens33
2: ens33:  mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 00:0c:29:8d:ce:8a brd ff:ff:ff:ff:ff:ff
    altname enp2s1
    inet 192.168.200.163/24 brd 192.168.200.255 scope global noprefixroute ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::ce91:fe4e:625d:6e32/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever

停掉之后vip不存在了，切换到master02 来看看

[root@master02 ~]# ip a show ens33
2: ens33:  mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 00:0c:29:2d:b0:8a brd ff:ff:ff:ff:ff:ff
    altname enp2s1
    inet 192.168.200.164/24 brd 192.168.200.255 scope global noprefixroute ens33
       valid_lft forever preferred_lft forever
    inet 192.168.200.200/32 scope global ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::f409:2f97:f02e:a8d4/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
 

现在vip跑到master02了，将master01的keepalived启动，vip会回来，因为master01的

优先级高于他

[root@master01 ~]# systemctl restart keepalived.service 
[root@master01 ~]# systemctl enable --now nginx keepalived.service 
Created symlink /etc/systemd/system/multi-user.target.wants/nginx.service → /usr/lib/systemd/system/nginx.service.
Created symlink /etc/systemd/system/multi-user.target.wants/keepalived.service → /usr/lib/systemd/system/keepalived.service.

4. 部署k8s

欧拉目前只支持1.23版本，所以目前的容器运行时是docker，没有写执行节点那么就是master01

4.1 安装软件包(所有master节点)

[root@master01 ~]# yum install kubeadm kubelet kubectl -y
[root@master01 ~]# systemctl enable kubelet

4.3 生成部署文件

[root@master01 ~]# kubeadm config print init-defaults > init.yaml

4.3.1 修改部署文件

[root@master01 ~]# vim init.yaml
apiVersion: kubeadm.k8s.io/v1beta3
bootstrapTokens:
- groups:
  - system:bootstrappers:kubeadm:default-node-token
  token: abcdef.0123456789abcdef
  ttl: 24h0m0s
  usages:
  - signing
  - authentication
kind: InitConfiguration
localAPIEndpoint:
  advertiseAddress: 192.168.200.163       # 这个地方需要修改为自己的IP地址  
  bindPort: 6443
nodeRegistration:
  criSocket: /var/run/dockershim.sock
  imagePullPolicy: IfNotPresent
  name: master01 # 这个地方改成你的主机名或者IP，作用是集群部署出来之后在集群内显示的名称，这里写什么到时候就是什么
  taints: null
---
apiServer:
  timeoutForControlPlane: 4m0s
  certSANs:  # 添加这一整段，目的是让这些地址所在的主机都能够使用证书
  - master01
  - master02
  - master03
  - 127.0.0.1
  - localhost
  - kubernetes
  - kubernetes.default
  - kubernetes.default.svc
  - kubernetes.default.svc.cluster.local
  - 192.168.200.163  # 这里3个是master的IP地址
  - 192.168.200.164
  - 192.168.200.165
  - 192.168.200.200  # VIP也需要写上
controlPlaneEndpoint: 192.168.200.200:16443  # 添加这一行，IP为VIP
apiVersion: kubeadm.k8s.io/v1beta3
certificatesDir: /etc/kubernetes/pki
clusterName: kubernetes
controllerManager: {}
dns: {}
etcd:
  local:
    dataDir: /var/lib/etcd
imageRepository: swr.cn-east-3.myhuaweicloud.com/hcie_openeuler   # 镜像仓库要改为国内的
kind: ClusterConfiguration
kubernetesVersion: 1.23.1   # 改为kubeadm版本一样的
networking:
  dnsDomain: cluster.local
  podSubnet: 10.244.0.0/12  # 添加这一行
  serviceSubnet: 10.96.0.0/12
scheduler: {}
---   # 添加这一整段
apiVersion: kubeproxy.config.k8s.io/v1alpha1
kind: KubeProxyConfiguration
mode: ipvs

4.4 提前拉取镜像

# 这是在部署之前提前先把镜像拉取下来
[root@master01 ~]# kubeadm config images pull --config ./init.yaml

4.5 开始部署

[root@master01 ~]# kubeadm init --upload-certs --config ./init.yaml 
# 如果安装失败了可以执行kubeadm reset -f 重置环境再来init，如果直接init会报错

执行成功之后会输出一些信息

  mkdir -p $HOME/.kube
  sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
  sudo chown $(id -u):$(id -g) $HOME/.kube/config
 
You can now join any number of the control-plane node running the following command on each as root:
# 加入新的master节点使用这个命令
  kubeadm join 192.168.200.200:16443 --token abcdef.0123456789abcdef \
	--discovery-token-ca-cert-hash sha256:de0e41b3bc59d2879af43da29f3f25cc1b133efda1f202d4c4ce5f865cad71d3 \
	--control-plane --certificate-key 8be5d0b8d4914a930d58c4171e748210cbdd118befa0635ffcc1031b7840386e
 
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:
# 加入node节点就使用这个命令
kubeadm join 192.168.200.200:16443 --token abcdef.0123456789abcdef \
	--discovery-token-ca-cert-hash sha256:de0e41b3bc59d2879af43da29f3f25cc1b133efda1f202d4c4ce5f865cad71d3 

4.6 其他master节点加入集群

生成的token只有24小时有效，如果token过期了还需要有节点加入集群的话可以执行

[root@master01 ~]# kubeadm token create --print-join-command
kubeadm join 192.168.200.200:16443 --token gb00dz.tevdizf7mxqx1egj --discovery-token-ca-cert-hash sha256:de0e41b3bc59d2879af43da29f3f25cc1b133efda1f202d4c4ce5f865cad71d3 这个命令可以直接让node节点加入

如果需要加入master节点，那么需要加上 --control-plane --certificate-key 8be5d0b8d4914a930d58c4171e748210cbdd118befa0635ffcc1031b7840386e

[root@master02 ~]# kubeadm join 192.168.200.200:16443 --token abcdef.0123456789abcdef \
	--discovery-token-ca-cert-hash sha256:de0e41b3bc59d2879af43da29f3f25cc1b133efda1f202d4c4ce5f865cad71d3 \
	--control-plane --certificate-key 8be5d0b8d4914a930d58c4171e748210cbdd118befa0635ffcc1031b7840386e
[root@master02 ~]# mkdir -p $HOME/.kube
[root@master02 ~]# sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
[root@master02 ~]# sudo chown $(id -u):$(id -g) $HOME/.kube/config	
 
[root@master03 ~]# kubeadm join 192.168.200.200:16443 --token abcdef.0123456789abcdef \
	--discovery-token-ca-cert-hash sha256:de0e41b3bc59d2879af43da29f3f25cc1b133efda1f202d4c4ce5f865cad71d3 \
	--control-plane --certificate-key 8be5d0b8d4914a930d58c4171e748210cbdd118befa0635ffcc1031b7840386e
[root@master03 ~]# mkdir -p $HOME/.kube
[root@master03 ~]# sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
[root@master03 ~]# sudo chown $(id -u):$(id -g) $HOME/.kube/config	

可以使用 --node-name 指定加入集群后的名字

4.7 node节点加入集群

[root@node ~]# kubeadm join 192.168.200.200:16443 --token abcdef.0123456789abcdef \
        --discovery-token-ca-cert-hash sha256:de0e41b3bc59d2879af43da29f3f25cc1b133efda1f202d4c4ce5f865cad71d3

4.8 查看集群节点

[root@master01 ~]# kubectl get nodes
NAME       STATUS     ROLES                  AGE   VERSION
master01   NotReady   control-plane,master   45m   v1.23.1
master02   NotReady   control-plane,master   27m   v1.23.1
master03   NotReady   control-plane,master   27m   v1.23.1
node       NotReady                    10s   v1.23.1

5. 安装网络插件 calico

没安装网络插件之前状态是NotReady，装完之后就是Ready

calico官方安装文档

在官方文档里面可以找到最新的版本

[root@master01 ~]# wget https://docs.projectcalico.org/archive/v3.23/manifests/calico.yaml
[root@master01 ~]# kubectl apply -f calico.yaml

稍等一会之后，查看集群节点状态

[root@master01 ~]# kubectl get nodes
NAME       STATUS   ROLES                  AGE     VERSION
master01   Ready    control-plane,master   5h38m   v1.23.1
master02   Ready    control-plane,master   5h21m   v1.23.1
master03   Ready    control-plane,master   5h21m   v1.23.1
node       Ready                     4h53m   v1.23.1

如果等了很久还没有ready的话可以使用

[root@master01 ~]# kubectl get pods -A

看看那些pod没有起来，找到原因并解决之后就可以了

6. 验证集群是否可用

[root@master01 ~]# kubectl run web01 --image nginx:1.24
pod/web01 created
[root@master01 ~]# kubectl get pods
NAME    READY   STATUS    RESTARTS   AGE
web01   1/1     Running   0          27s

能够正常启动pod