Kubernetes

kubeadm安装生产环境多master节点k8s高可用集群

本文主要是介绍kubeadm安装生产环境多master节点k8s高可用集群,对大家解决编程问题具有一定的参考价值,需要的程序猿们随着小编来一起学习吧!

 环境准备

三台虚拟机(所有节点做好host解析)

cat /etc/hosts
127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4
::1 localhost localhost.localdomain localhost6 localhost6.localdomain6
10.0.0.128 k8s-node
10.0.0.129 k8s-master1
10.0.0.130 k8s-master2

  kubeadm是工具,可以快速搭建集群,属于自动部署,简化部署操作。kubeadm适合需要经常部署k8s,或者对自动化要求比较高的场景下使用。

一、初始化安装k8s集群的实验环境   1. 修改网卡配置文件
[root@k8s-node ~]# cat /etc/sysconfig/network-scripts/ifcfg-eth0
TYPE=Ethernet
BOOTPROTO=static
DEFROUTE=yes
NAME=eth0
DEVICE=eth0
ONBOOT=yes
IPADDR=10.0.0.128
NETMASK=255.255.255.0
GATEWAY=10.0.0.254
DNS1=8.8.8.8
[root@k8s-master1 ~]# cat /etc/sysconfig/network-scripts/ifcfg-eth0 
TYPE=Ethernet
BOOTPROTO=static
DEFROUTE=yes
NAME=eth0
DEVICE=eth0
ONBOOT=yes
IPADDR=10.0.0.129
NETMASK=255.255.255.0
GATEWAY=10.0.0.254
DNS1=8.8.8.8
[root@k8s-master2 ~]# cat /etc/sysconfig/network-scripts/ifcfg-eth0 
TYPE=Ethernet
BOOTPROTO=static
DEFROUTE=yes
NAME=eth0
DEVICE=eth0
ONBOOT=yes
IPADDR=10.0.0.130
NETMASK=255.255.255.0
GATEWAY=10.0.0.254
DNS1=8.8.8.8

#修改配置文件之后需要重启网络服务才能使配置生效

systemctl restart network

  2. 配置主机之间无密码登录

在k8s-node主机上操作:

[root@k8s-node ~]# ssh-keygen 

[root@k8s-node ~]# ssh-copy-id k8s-master2

[root@k8s-node ~]# ssh-copy-id  k8s-master1

在k8s-master1主机上操作:

[root@k8s-master1 ~]# ssh-keygen 

[root@k8s-master1 ~]# ssh-copy-id k8s-master2

[root@k8s-master1 ~]# ssh-copy-id  k8s-node

在k8s-master2主机上操作:

[root@k8s-master2 ~]# ssh-keygen 

[root@k8s-master2 ~]# ssh-copy-id k8s-master1

[root@k8s-master2 ~]# ssh-copy-id  k8s-node

或者用脚本实现

yum install -y sshpass
ssh-keygen -f /root/.ssh/id_rsa -P ''
export IP=:10.0.0.128 10.0.0.129 10.0.0.130"
export SSHPASS=kvm-kvm@ECS

for HOST in $IP;do
    sshpass -e ssh-copy-id -o StrictHostKeyChecking=no $HOST;
done

  3. 关闭交换分区swap,提升性能

#临时关闭

[root@k8s-node ~]# swapoff -a
[root@k8s-master1 ~]# swapoff -a
[root@k8s-master2 ~]# swapoff -a

#永久关闭,注释swap挂载,给swap这行开头加一下注释

[root@k8s-node ~]# cat /etc/fstab

#
# /etc/fstab
# Created by anaconda on Thu Jul 21 04:56:59 2022
#
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
/dev/mapper/centos-root / xfs defaults 0 0
UUID=25df1604-f316-4d70-b007-e905a7ec9d55 /boot xfs defaults 0 0
#/dev/mapper/centos-swap swap swap defaults 0 0
[root@k8s-master1 ~]# cat /etc/fstab

#
# /etc/fstab
# Created by anaconda on Sun Jul 24 17:18:04 2022
#
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
/dev/mapper/centos-root / xfs defaults 0 0
UUID=ec12e2e1-faeb-432d-b5f6-2768a14c6e9c /boot xfs defaults 0 0
#/dev/mapper/centos-swap swap swap defaults 0 0
[root@k8s-master2 ~]# cat /etc/fstab

#
# /etc/fstab
# Created by anaconda on Sun Jul 24 17:18:04 2022
#
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
/dev/mapper/centos-root / xfs defaults 0 0
#/dev/mapper/centos-swap swap swap defaults 0 0

  关闭swap分区的原因:

  Swap是交换分区,如果机器内存不够,会使用swap分区,但是swap分区的性能较低,k8s设计的时候为了能提升性能,默认是不允许使用交换分区的。Kubeadm初始化的时候会检测swap是否关闭,如果没关闭,那就初始化失败。如果不想要关闭交换分区,安装k8s的时候可以指定--ignore-preflight-errors=Swap来解决

   4.  修改机器内核参数

[root@k8s-master1 ~]# modprobe br_netfilter

[root@k8s-master1 ~]# cat > /etc/sysctl.d/k8s.conf <<EOF

>net.bridge.bridge-nf-call-ip6tables = 1
>net.bridge.bridge-nf-call-iptables = 1
>net.ipv4.ip_forward = 1
>EOF

[root@k8s-master1 ~]# sysctl -p /etc/sysctl.d/k8s.conf 

其他节点同理,相同的操作

  要让Linux系统具有路由转发功能,需要配置一个Linux的内核参数net.ipv4.ip_forward。这个参数指定了Linux系统当前对路由转发功能的支持情况;其值为0时表示禁止进行IP转发;如果是1,则说明IP转发功能已经打开。

  5. 关闭关闭firewalld防火墙,selinux

[root@k8s-master1 ~]# systemctl stop firewalld ; systemctl disable firewalld

[root@k8s-master1 ~]# sed -i 's/SELINUX=enforcing/SELINUX=disabled/g' /etc/selinux/config

[root@k8s-master1 ~]# reboot

[root@k8s-master1 ~]# getenforce

  其他节点相同操作

  6. 配置清华k8s源

[root@k8s-master1 ~]# cat  /etc/yum.repos.d/kubernetes.repo 
[kubernetes]
name=kubernetes
baseurl=https://mirrors.tuna.tsinghua.edu.cn/kubernetes/yum/repos/kubernetes-el7-$basearch
enabled=1

  其他节点配置相同的源

  7. 开启ipvs

[root@k8s-master1 ~]# cat /etc/sysconfig/modules/ipvs.modules

#!/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
[root@k8s-master1 ~]# bash /etc/sysconfig/modules/ipvs.modules 

  其他节点相理,做相同的操作

  ipvs (IP Virtual Server) 实现了传输层负载均衡,ipvs运行在主机上,在真实服务器集群前充当负载均衡器。ipvs可以将基于TCP和UDP的服务请求转发到真实服务器上,并使真实服务器的服务在单个 IP 地址上显示为虚拟服务。

  kube-proxy支持 iptables 和 ipvs 两种模式。 iptables 就是 kube-proxy 默认的操作模式,ipvs 和 iptables 都是基于netfilter的,但是ipvs采用的是hash表,因此当service数量达到一定规模时,hash查表的速度优势就会显现出来,从而提高service的服务性能。

  1)、ipvs 为大型集群提供了更好的可扩展性和性能

  2)、ipvs 支持比 iptables 更复杂的复制均衡算法(最小负载、最少连接、加权等等)

  3)、ipvs 支持服务器健康检查和连接重试等功能

二、 安装docker服务

[root@k8s-master1 ~]# yum install yum-utils device-mapper-persistent-data lvm2

[root@k8s-master1 ~]# curl -o /etc/yum.repos.d/docker-ce.repo https://mirrors.ustc.edu.cn/docker-ce/linux/centos/docker-ce.repo

[root@k8s-master1 ~]# sed -i 's#download.docker.com#mirrors.tuna.tsinghua.edu.cn/docker-ce#g' /etc/yum.repos.d/docker-ce.repo

[root@k8s-master1 ~]# yum install docker-ce-20.10.6 docker-ce-cli-20.10.6 containerd.io  -y

[root@k8s-master1 ~]# systemctl start docker

[root@k8s-master1 ~]# systemctl enable docker
Created symlink from /etc/systemd/system/multi-user.target.wants/docker.service to /usr/lib/systemd/system/docker.service.

  #配置加速器

[root@k8s-master1 ~]# cat /etc/docker/daemon.json
{ 
    "registry-mirrors": ["https://docker.mirrors.ustc.edu.cn","https://reg-mirror.qiniu.com/","https://hub-mirror.c.163.com/"],
    "exec-opts": ["native.cgroupdriver=systemd"]
}

[root@k8s-master1 ~]# systemctl daemon-reload && systemctl restart docker

  k8s-master2和k8s-node节点相同

三、安装初始化k8s需要的软件包

[root@k8s-master1 ~]# yum install kubelet-1.20.6 kubeadm-1.20.6 kubectl-1.20.6 --nogpgcheck -y

[root@k8s-master1 ~]# systemctl enable kubelet && systemctl start kubelet
[root@k8s-master1 ~]# systemctl status kubelet
● kubelet.service - kubelet: The Kubernetes Node Agent
Loaded: loaded (/usr/lib/systemd/system/kubelet.service; enabled; vendor preset: disabled)
Drop-In: /usr/lib/systemd/system/kubelet.service.d
└─10-kubeadm.conf
Active: activating (auto-restart) (Result: exit-code) since Wed 2022-07-27 23:47:32 CST; 9s ago
Docs: https://kubernetes.io/docs/
Process: 4919 ExecStart=/usr/bin/kubelet $KUBELET_KUBECONFIG_ARGS $KUBELET_CONFIG_ARGS $KUBELET_KUBEADM_ARGS $KUBELET_EXTRA_ARGS (code=exited, status=255)
Main PID: 4919 (code=exited, status=255)

Jul 27 23:47:32 k8s-master1 systemd[1]: kubelet.service: main process exited, code=exited, status=255/n/a
Jul 27 23:47:32 k8s-master1 systemd[1]: Unit kubelet.service entered failed state.
Jul 27 23:47:32 k8s-master1 systemd[1]: kubelet.service failed.

注:ubelet状态不是running状态,这个是正常的,不用管,等k8s组件起来这个kubelet就正常了。

[root@k8s-master1 ~]# kubelet --version
Kubernetes v1.20.6

  其他节点相同的操作

  kubeadm:  kubeadm是一个工具,用来初始化k8s集群的

  kubelet:   安装在集群所有节点上,用于启动Pod的

  kubectl:   通过kubectl可以部署和管理应用,查看各种资源,创建、删除和更新各种组件

四、通过keepalive+nginx实现k8s apiserver节点高可用

  1. 安装keepalive 和nginx

在k8s-master1和k8s-master2上做nginx主备安装(配置文件相同)

[root@k8s-master1 ~]# yum install nginx keepalived -y

  2. 修改nginx配置文件。主备一样

[root@k8s-master1 ~]# cat /etc/nginx/nginx.conf
user nginx;
worker_processes auto;
error_log /var/log/nginx/error.log;
pid /run/nginx.pid;

include /usr/share/nginx/modules/*.conf;

events {
    worker_connections 1024;
}

# 四层负载均衡,为两台Master apiserver组件提供负载均衡
stream {

    log_format  main  '$remote_addr $upstream_addr - [$time_local] $status $upstream_bytes_sent';

    access_log  /var/log/nginx/k8s-access.log  main;

    upstream k8s-apiserver {
       server 10.0.0.129:6443;   # Master1 APISERVER IP:PORT
       server 10.0.0.130:6443;   # Master2 APISERVER IP:PORT
    }
    
    server {
       listen 16443; # 由于nginx与master节点复用,这个监听端口不能是6443,否则会冲突
       proxy_pass k8s-apiserver;
    }
}

http {
    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';

    access_log  /var/log/nginx/access.log  main;

    sendfile            on;
    tcp_nopush          on;
    tcp_nodelay         on;
    keepalive_timeout   65;
    types_hash_max_size 2048;

    include             /etc/nginx/mime.types;
    default_type        application/octet-stream;

    server {
        listen       80 default_server;
        server_name  _;

        location / {
        }
    }
}

  查看配置文件是否正确

[root@k8s-master1 ~]# nginx -t
nginx: [emerg] unknown directive "stream" in /etc/nginx/nginx.conf:13
nginx: configuration file /etc/nginx/nginx.conf test failed

  定位原因是nginx缺少modules模块

[root@k8s-master1 ~]# yum install -y nginx-all-modules.noarch

  再次检查配置文件正常

[root@k8s-master1 ~]# nginx -t
nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: configuration file /etc/nginx/nginx.conf test is successful

  3. keepalive配置

主keepalived

[root@k8s-master1 ~]# cat /etc/keepalived/keepalived.conf

global_defs {

   notification_email {

     acassen@firewall.loc

     failover@firewall.loc

     sysadmin@firewall.loc

   }

   notification_email_from Alexandre.Cassen@firewall.loc 

   smtp_server 127.0.0.1

   smtp_connect_timeout 30

   router_id NGINX_MASTER

}

vrrp_script check_nginx {

    script "/etc/keepalived/check_nginx.sh"

}

vrrp_instance VI_1 {

    state MASTER

    interface eth0        # 修改为实际网卡名

    virtual_router_id 51  # VRRP 路由 ID实例,每个实例是唯一的

    priority 100     # 优先级,主服务器设置100,备服务器设置 90

    advert_int 1     # 指定VRRP 心跳包通告间隔时间,默认1秒

    authentication {

        auth_type PASS     

        auth_pass 1111

    } 

    # 虚拟IP

    virtual_ipaddress {

        10.0.0.131/24

    }

    track_script {

        check_nginx

    }

}

  vrrp_script:指定检查nginx工作状态脚本(根据nginx状态判断是否故障转移)

  virtual_ipaddress:虚拟IP(VIP)

[root@k8s-master1 ~]# cat /etc/keepalived/check_nginx.sh

#!/bin/bash

#1、判断Nginx是否存活

counter=`ps -C nginx --no-header | wc -l`

if [ $counter -eq 0 ]; then

    #2、如果不存活则尝试启动Nginx

    service nginx start

    sleep 2

    #3、等待2秒后再次获取一次Nginx状态

    counter=`ps -C nginx --no-header | wc -l`

    #4、再次进行判断,如Nginx还不存活则停止Keepalived,让地址进行漂移

    if [ $counter -eq 0 ]; then

        service  keepalived stop

    fi

fi
[root@k8s-master1 ~]# scp /etc/keepalived/check_nginx.sh root@k8s-master2:/etc/keepalived/check_nginx.sh

[root@xianchaomaster1 ~]# chmod +x  /etc/keepalived/check_nginx.sh

备keepalive

[root@k8s-master2 ~]# cat /etc/keepalived/keepalived.conf

global_defs {

   notification_email {

     acassen@firewall.loc

     failover@firewall.loc

     sysadmin@firewall.loc

   }

   notification_email_from Alexandre.Cassen@firewall.loc 

   smtp_server 127.0.0.1

   smtp_connect_timeout 30

   router_id NGINX_MASTER

} 

vrrp_script check_nginx {

    script "/etc/keepalived/check_nginx.sh"

}

vrrp_instance VI_1 {

    state BACKUP

    interface eth0        # 修改为实际网卡名

    virtual_router_id 51  # VRRP 路由 ID实例,每个实例是唯一的

    priority 90     # 优先级,备服务器设置 90

    advert_int 1     # 指定VRRP 心跳包通告间隔时间,默认1秒

    authentication {

        auth_type PASS     

        auth_pass 1111

    } 

    # 虚拟IP

    virtual_ipaddress {

        10.0.0.131/24

    }

    track_script {

        check_nginx

    }

}
[root@k8s-master2 ~]# cat /etc/keepalived/check_nginx.sh

#!/bin/bash

counter=`ps -C nginx --no-header | wc -l`

if [ $counter -eq 0 ]; then

    service nginx start

    sleep 2

    counter=`ps -C nginx --no-header | wc -l`

    if [ $counter -eq 0 ]; then

        service  keepalived stop

    fi

fi

[root@xianchaomaster2 ~]# chmod +x  /etc/keepalived/check_nginx.sh

  4. 启动服务

[root@k8s-master1 keepalived]# systemctl daemon-reload

[root@k8s-master1 keepalived]# systemctl start nginx

[root@k8s-master1 keepalived]# systemctl status nginx

[root@k8s-master1 keepalived]# systemctl start keepalived

[root@k8s-master1 keepalived]# systemctl status keepalived

[root@k8s-master1 ~]# systemctl enable nginx
Created symlink from /etc/systemd/system/multi-user.target.wants/nginx.service to /usr/lib/systemd/system/nginx.service.

[root@k8s-master1 ~]# systemctl enable keepalived
Created symlink from /etc/systemd/system/multi-user.target.wants/keepalived.service to /usr/lib/systemd/system/keepalived.service.

  k8s-master2 相同,启动服务

  vip绑定成功

  5.  测试keepalived

  #停掉k8s-master1上的nginx或者keepalived,查看vip是否会漂移到k8s-master2上 

[root@k8s-master1 ~]# systemctl stop keepalived

五、kubeadm初始化k8s集群

  初始化k8s集群需要的离线镜像包上传到三个节点上

[root@k8s-master1 images]# docker load -i k8simage-1-20-6.tar.gz
[root@k8s-master2 images]# docker load -i k8simage-1-20-6.tar.gz
[root@k8s-node images]# docker load -i k8simage-1-20-6.tar.gz

  创建kubeadm-config.yaml文件:

[root@k8s-master1 ~]# cat kubeadm-config.yaml 
apiVersion: kubeadm.k8s.io/v1beta2
kind: ClusterConfiguration
kubernetesVersion: v1.20.6
controlPlaneEndpoint: 10.0.0.131:16443
imageRepository: registry.aliyuncs.com/google_containers
apiServer:
 certSANs:
 - 10.0.0.128
 - 10.0.0.129
 - 10.0.0.130
 - 10.0.0.131
networking:
  podSubnet: 10.244.0.0/16
  serviceSubnet: 10.10.0.0/16
---
apiVersion: kubeproxy.config.k8s.io/v1alpha1
kind:  KubeProxyConfiguration
mode: ipvs

  注:生成kubeadm默认配置文件,执行如下命令:

[root@k8s-master1 ~]# kubeadm config print init-defaults > init-config.yaml

  初始化命令如下:

[root@k8s-master1 ~]# kubeadm init --config kubeadm-config.yaml --ignore-preflight-errors=SystemVerification 

  注:若初始化有问题,修改init-config.yaml,先重置kubeadm,然后再执行kubeadm init命令

[root@k8s-master1 ~]# kubeadm reset -f     #重置命令 
[root@k8s-master1 ~]# kubeadm init --config kubeadm-config.yaml --ignore-preflight-errors=SystemVerification

  显示如下截图,表明初始化成功

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

Alternatively, if you are the root user, you can run:

  export KUBECONFIG=/etc/kubernetes/admin.conf

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 control-plane nodes by copying certificate authorities
and service account keys on each node and then running the following as root:

  kubeadm join 10.0.0.131:16443 --token 4zorkh.jn5cjqr4chab0mdt \
    --discovery-token-ca-cert-hash sha256:8843d4409ec381f6c3747f0ffa7620075e60cb29f48f2eae8fe3c2f835839bfc \
    --control-plane 

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

kubeadm join 10.0.0.131:16443 --token 4zorkh.jn5cjqr4chab0mdt \
    --discovery-token-ca-cert-hash sha256:8843d4409ec381f6c3747f0ffa7620075e60cb29f48f2eae8fe3c2f835839bfc 

  根据上述提示命令配置kubectl的配置文件config,相当于对kubectl进行授权,这样kubectl命令可以使用这个证书对k8s集群进行管理

[root@k8s-master1 ~]# mkdir -p $HOME/.kube
[root@k8s-master1 ~]# sudo cp -i /etc/kubernetes/admin.conf 
[root@k8s-master1 ~]# sudo chown $(id -u):$(id -g) $HOME/.kube/config

  查看集群状态

[root@k8s-master1 ~]# kubectl get nodes
NAME          STATUS     ROLES                  AGE     VERSION
k8s-master1   NotReady   control-plane,master   8m42s   v1.20.6

  节点显示不正常,此时集群状态还是NotReady状态,因为没有安装网络插件。

六、扩容k8s集群-添加master节点

  1. 在k8s-master2上创建证书存放目录

[root@k8s-master2 ~]# cd /root && mkdir -p /etc/kubernetes/pki/etcd &&mkdir -p ~/.kube/

  2. 将k8s-master1上的证书拷贝到k8s-master2上

[root@k8s-master1 ~]# scp /etc/kubernetes/pki/ca.*  k8s-master2:/etc/kubernetes/pki/
ca.crt                                                                                                     100% 1066   381.7KB/s   00:00    
ca.key                                                                                                     100% 1679   579.4KB/s   00:00    
[root@k8s-master1 ~]# scp /etc/kubernetes/pki/sa.*  k8s-master2:/etc/kubernetes/pki/
sa.key                                                                                                     100% 1679   451.8KB/s   00:00    
sa.pub                                                                                                     100%  451   139.6KB/s   00:00    
[root@k8s-master1 ~]# scp /etc/kubernetes/pki/front-proxy-ca.*  k8s-master2:/etc/kubernetes/pki/
front-proxy-ca.crt                                                                                         100% 1078   566.0KB/s   00:00    
front-proxy-ca.key                                                                                         100% 1675    28.4KB/s   00:00    
[root@k8s-master1 ~]# scp /etc/kubernetes/pki/etcd/ca.*  k8s-master2:/etc/kubernetes/pki/etcd/
ca.crt                                                                                                     100% 1058   318.9KB/s   00:00    
ca.key                                                                                                     100% 1679   585.2KB/s   00:00    

  3. 添加master节点,在k8s-master2上执行如下命令:

[root@k8s-master2 ~]# kubeadm join 10.0.0.131:16443 --token 4zorkh.jn5cjqr4chab0mdt --discovery-token-ca-cert-hash sha256:8843d4409ec381f6c3747f0ffa7620075e60cb29f48f2eae8fe3c2f835839bfc --control-plane 

  显示如下图所示,说明已经加入集群

注:token有效期是有限的,如果旧的token过期,可以使用kubeadm token create --print-join-command重新创建一条token

  4. 在k8s-master1上查看集群状况

[root@k8s-master1 ~]# kubectl get nodes
NAME          STATUS     ROLES                  AGE     VERSION
k8s-master1   NotReady   control-plane,master   17m     v1.20.6
k8s-master2   NotReady   control-plane,master   3m15s   v1.20.6

  可以看到k8s-master2已经加入集群

七 、扩容k8s集群-添加node节点

  1. 在k8s-master1上查看加入加入节点的命令

[root@k8s-master1 ~]# kubeadm token create --print-join-command
kubeadm join 10.0.0.131:16443 --token 6cidtt.kgl82ugmll1e9fbi     --discovery-token-ca-cert-hash sha256:8843d4409ec381f6c3747f0ffa7620075e60cb29f48f2eae8fe3c2f835839bfc 

  2. 在k8s-node节点上执行如下命令,将k8s-node节点加入到集群中

[root@k8s-node ~]# kubeadm join 10.0.0.131:16443 --token 4zorkh.jn5cjqr4chab0mdt --discovery-token-ca-cert-hash sha256:8843d4409ec381f6c3747f0ffa7620075e60cb29f48f2eae8fe3c2f835839bfc 

  显示如下图所示,表明加入成功

  3. 在k8s-master1上查看集群状况

[root@k8s-master1 ~]# kubectl get nodes
NAME          STATUS     ROLES                  AGE     VERSION
k8s-master1   NotReady   control-plane,master   22m     v1.20.6
k8s-master2   NotReady   control-plane,master   8m41s   v1.20.6
k8s-node      NotReady   <none>                 46s     v1.20.6

八、安装kubernetes网络组件-Calico

  注:在线下载配置文件地址是: https://docs.projectcalico.org/manifests/calico.yaml 

[root@k8s-master1 ~]# kubectl apply -f https://docs.projectcalico.org/manifests/calico.yaml

  显示报错信息如下:

  将该文件下载下来,修改版本信息为:policy/v1beta1,重新执行

[root@k8s-master1 ~]# kubectl apply -f calico.yaml

  查看node节点信息

[root@k8s-master1 ~]# kubectl get nodes
NAME          STATUS   ROLES                  AGE   VERSION
k8s-master1   Ready    control-plane,master   37m   v1.20.6
k8s-master2   Ready    control-plane,master   23m   v1.20.6
k8s-node      Ready    <none>                 15m   v1.20.6

  已显示Ready状态

  查看集群信息

[root@k8s-master1 ~]# kubectl get pods -n kube-system
NAME                                       READY   STATUS    RESTARTS   AGE
calico-kube-controllers-6949477b58-mx6wz   1/1     Running   1          19m
calico-node-58k68                          1/1     Running   3          19m
calico-node-cnkd4                          1/1     Running   2          19m
calico-node-vk766                          1/1     Running   3          19m
coredns-7f89b7bc75-5l98h                   1/1     Running   0          49m
coredns-7f89b7bc75-gcqx6                   1/1     Running   0          49m
etcd-k8s-master1                           1/1     Running   2          49m
etcd-k8s-master2                           1/1     Running   2          35m
kube-apiserver-k8s-master1                 1/1     Running   4          49m
kube-apiserver-k8s-master2                 1/1     Running   2          35m
kube-controller-manager-k8s-master1        1/1     Running   6          49m
kube-controller-manager-k8s-master2        1/1     Running   5          35m
kube-proxy-4js8h                           1/1     Running   0          49m
kube-proxy-fq2nb                           1/1     Running   0          35m
kube-proxy-t4ptw                           1/1     Running   0          27m
kube-scheduler-k8s-master1                 1/1     Running   5          49m
kube-scheduler-k8s-master2                 1/1     Running   4          35m

九、测试在k8s创建pod是否可以正常访问网络

[root@k8s-master1 ~]# kubectl run busybox --image busybox:latest --restart=Never --rm -it busybox -- sh
If you don't see a command prompt, try pressing enter.
/ # ifconfig
eth0      Link encap:Ethernet  HWaddr 4E:53:0F:E0:E0:D4  
          inet addr:10.244.113.133  Bcast:10.244.113.133  Mask:255.255.255.255
          UP BROADCAST RUNNING MULTICAST  MTU:1480  Metric:1
          RX packets:5 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:438 (438.0 B)  TX bytes:0 (0.0 B)

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1 
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

/ # ping baidu.com
PING baidu.com (39.156.66.10): 56 data bytes
64 bytes from 39.156.66.10: seq=0 ttl=127 time=28.332 ms
64 bytes from 39.156.66.10: seq=1 ttl=127 time=27.305 ms
64 bytes from 39.156.66.10: seq=2 ttl=127 time=27.632 ms
64 bytes from 39.156.66.10: seq=3 ttl=127 time=31.171 ms
^C
--- baidu.com ping statistics ---
4 packets transmitted, 4 packets received, 0% packet loss
round-trip min/avg/max = 27.305/28.610/31.171 ms

  可以看到能访问网络,说明calico网络插件已经被正常安装了

十、测试k8s集群中部署tomcat服务

  将tomcat镜像文件上传至k8s-node节点上,获取tomcat:8.5-jre8-alpine此镜像

[root@k8s-node images]# docker load -i tomcat.tar.gz 
f1b5933fe4b5: Loading layer [==================================================>]  5.796MB/5.796MB
9b9b7f3d56a0: Loading layer [==================================================>]  3.584kB/3.584kB
edd61588d126: Loading layer [==================================================>]  80.28MB/80.28MB
48988bb7b861: Loading layer [==================================================>]   2.56kB/2.56kB
8e0feedfd296: Loading layer [==================================================>]  24.06MB/24.06MB
aac21c2169ae: Loading layer [==================================================>]  2.048kB/2.048kB
Loaded image: tomcat:8.5-jre8-alpine

  创建一个tomcat的pod

[root@k8s-master1 ~]# cat >tomcat.yaml <<EOF
> apiVersion: v1  #pod属于k8s核心组v1
> kind: Pod  #创建的是一个Pod资源
> metadata:  #元数据
>   name: demo-pod  #pod名字
>   namespace: default  #pod所属的名称空间
>   labels:
>     app: myapp  #pod具有的标签
>     env: dev      #pod具有的标签
> spec:
>   containers:      #定义一个容器,容器是对象列表,下面可以有多个name
>   - name:  tomcat-pod-java  #容器的名字
>     ports:
>     - containerPort: 8080
>     image: tomcat:8.5-jre8-alpine   #容器使用的镜像
>     imagePullPolicy: IfNotPresent
> EOF
[root@k8s-master1 ~]# kubectl apply -f tomcat.yaml
pod/demo-pod created
[root@k8s-master1 ~]# kubectl get pods
NAME       READY   STATUS              RESTARTS   AGE
demo-pod   0/1     ContainerCreating   0          12s
[root@k8s-master1 ~]# kubectl get pods
NAME       READY   STATUS    RESTARTS   AGE
demo-pod   1/1     Running   0          18s

  创建一个service可以访问tomcat

[root@k8s-master1 ~]# cat >tomcat-service.yaml <<EOF
> apiVersion: v1
> kind: Service
> metadata:
>   name: tomcat
> spec:
>   type: NodePort
>   ports:
>     - port: 8080
>       nodePort: 30080    #外部端口访问
>   selector:
>     app: myapp
>     env: dev
> EOF
[root@k8s-master1 ~]# kubectl apply -f tomcat-service.yaml 
service/tomcat created
[root@k8s-master1 ~]# kubectl get svc
NAME         TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)          AGE
kubernetes   ClusterIP   10.10.0.1       <none>        443/TCP          78m
tomcat       NodePort    10.10.104.169   <none>        8080:30080/TCP   19s

  在浏览器访问k8s-node节点的ip:30080,可以看到tomcat页面:

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