注意:本文通过Docker+kubernetes(k8s)+DevOps企业级架构师实战培训课程实验所得,感谢先超老师!

准备工作

k8s环境规划

服务IP/Mask
Service网段10.0.0.0/16
Pod网段10.255.0.0/16
操作系统centos7.6
配置4Gib内存/6vCPU/100G硬盘
网络NAT
虚拟化服务开启虚拟机的虚拟化

VM开启虚拟机的虚拟化
在这里插入图片描述

基础架构

在这里插入图片描述

K8S集群角色IP主机名安装的组件
控制节点192.168.40.180kaivimaster1apiserver、controller-manager、scheduler、etcd、docker、keepalived、nginx
控制节点192.168.40.181kaivimaster2apiserver、controller-manager、scheduler、etcd、docker、keepalived、nginx
控制节点192.168.40.182kaivimaster3apiserver、controller-manager、scheduler、etcd、docker
工作节点192.168.40.183kaivinode1kubelet、kube-proxy、docker、calico、coredns
Vip192.168.40.199kaivimaster1/kaivimaster2keepalived、nginx

k8s 组件介绍

kubeapiserver

https://k8smeetup.github.io/docs/admin/kube-apiserver/

Kubernetes API server 为 api 对象验证并配置数据,包括 pods 、 services 、replicationcontrollers 和其它 api 对象 API Server 提供 REST 操作和到集群共享状态的前端,所有其他组件通过它进行交互。数据保存在etcd中。本身master集群不存储数据。

kubescheduler

https://k8smeetup.github.io/docs/admin/kube-scheduler/

kubescheduler 是一个拥有丰富策略、能够感知拓扑变化、支持特定负载的功能组件,它对集群的可用性、性能表现以及容量都影响巨大。 scheduler 需要考虑独立的和集体的资源需求、服务质量需求、硬件 软件 策略限制、亲和与反亲和规范、数据位置、内部负载接口、截止时间等等。如有必要,特定的负载需求可以通过 API 暴露出来。
亲和与反亲和:不同项目 不同部门的硬件资源是独立的,通常只有一套K8S 让指定的pod跑到指定的服务 可以让pod设置一些策略。让pod指定运行在node节点上,pod和节点node绑定/

kubecontroller manager

https://k8smeetup.github.io/docs/admin/kube-controller-manager/

Controller Manager 作为集群内部的管理控制中心,负责集群内的Node 、 Pod 副本、服务端点( Endpoint )、命名空间 Namespace )、服务账号 ServiceAccount )、资源定额( ResourceQuota )的管理,当某个 Node 意外宕机时, Controller Manager 会及时发现并执行自动化修复流程,确保集群始终处于预期的工作状态。

kubeproxy

https://k8smeetup.github.io/docs/admin/kube-proxy/

kubeproxy Kubernetes 网络代理运行在 node 上,它反映了 node 上 Kubernetes API 中定义的服务,并可以通过一组后端进行简单的 TCP 、 UDP 流转发或循环模式( round robin)的 TCP 、 UDP 转发,用户必须使用 apiserver API 创建一个服务来配置代理,其实 就是 kubeproxy 通过在主机上维护网络规则并执行连接转发来实现 Kubernetes 服务访问 。

kubelet

https://k8smeetup.github.io/docs/admin/kubelet/

kubelet 是主要的节点代理,它会监视已分配给节点的 pod ,具体功能 如下:

1.向master 汇报 node 节点的状态信息
2.接受指令并在Pod 中创建 docker 容器
3.准备Pod 所需的数据卷
4.返回pod的运行状态
5.在node 节点执行容器健康检查

etcd

https://github.com/etcd-io/etcd

etcd是 C oreOS 公司开发目前 是 Kubernetes 默认 使用 的 key value 数据 存储系统, 用于 保存所有集群数据, 支持 分布式集群功能 ,生产 环境使用 时 需要为 etcd 数据提供定期备份机制 。

https://kubernetes.io/zh/docs/concepts/overview/components/ #新版本组件介绍

https://etcd.io/docs/v3.4.0/ #etcd配置参考

初始化

配置静态IP

把虚拟机或者物理机配置成静态ip地址,这样机器重新启动后ip地址也不会发生改变。
以kaivimaster1主机修改静态IP为例:

#修改/etc/sysconfig/network-scripts/ifcfg-ens33(具体看网络网卡,有的是eth0)文件,变成如下:

# vim /etc/sysconfig/network-scripts/ifcfg-ens33
TYPE=Ethernet
PROXY_METHOD=none
BROWSER_ONLY=no
BOOTPROTO=static
IPADDR=192.168.40.180
NETMASK=255.255.255.0
GATEWAY=192.168.40.2
DNS1=192.168.40.2
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=ens33
DEVICE=ens33
ONBOOT=yes

#修改配置文件之后需要重启网络服务才能使配置生效,重启网络服务命令如下:

service network restart

注:/etc/sysconfig/network-scripts/ifcfg-ens33文件里的配置说明: NAME=ens33
#网卡名字,跟DEVICE名字保持一致即可 DEVICE=ens33
#网卡设备名,大家ip addr可看到自己的这个网卡设备名,每个人的机器可能这个名字不一样,需要写自己的 BOOTPROTO=static
#static表示静态ip地址 ONBOOT=yes
#开机自启动网络,必须是yes IPADDR=192.168.40.180
#ip地址,需要跟自己电脑所在网段一致 NETMASK=255.255.255.0
#子网掩码,需要跟自己电脑所在网段一致 GATEWAY=192.168.40.2
#网关,在自己电脑打开cmd,输入ipconfig /all可看到 DNS1=192.168.40.2
#DNS,在自己电脑打开cmd,输入ipconfig /all可看到

配置主机名

#配置主机名:

在192.168.40.180上执行如下:
hostnamectl set-hostname kaivimaster1

在192.168.40.181上执行如下:
hostnamectl set-hostname kaivimaster2

在192.168.40.182上执行如下:
hostnamectl set-hostname kaivimaster3

在192.168.40.183上执行如下:
hostnamectl set-hostname kaivinode1

配置hosts文件

#修改kaivimaster1、kaivimaster2、kaivimaster3、kaivinode1机器的/etc/hosts文件,增加如下四行:

# vim /etc/hosts
192.168.40.180   kaivimaster1
192.168.40.181   kaivimaster2
192.168.40.182   kaivimaster3
192.168.40.183   kaivinode1

主机节点免密

配置主机之间无密码登录,每台机器都按照如下操作

#生成ssh 密钥对
ssh-keygen -t rsa    #一路回车,不输入密码

把本地的ssh公钥文件安装到远程主机对应的账户
ssh-copy-id -i .ssh/id_rsa.pub kaivimaster1
ssh-copy-id -i .ssh/id_rsa.pub kaivimaster2
ssh-copy-id -i .ssh/id_rsa.pub kaivimaster3
ssh-copy-id -i .ssh/id_rsa.pub kaivinode1

关闭firewalld防火墙

关闭firewalld防火墙,在kaivimaster1、kaivimaster2、kaivimaster3、kaivinode1上操作:

systemctl stop firewalld 
systemctl disable firewalld
systemctl status firewalld

关闭selinux

关闭selinux,在kaivimaster1、kaivimaster2、kaivimaster3、kaivinode1上操作:

sed -i 's/SELINUX=enforcing/SELINUX=disabled/g' /etc/selinux/config
#修改selinux配置文件之后,重启机器,selinux配置才能永久生效
重启之后登录机器验证是否修改成功:
getenforce
#显示Disabled说明selinux已经关闭

关闭交换分区swap

关闭交换分区swap,在kaivimaster1、kaivimaster2、kaivimaster3、kaivinode1上操作:

#临时关闭
swapoff -a

#永久关闭:注释swap挂载,给swap这行开头加一下注释

vim /etc/fstab
#/dev/mapper/centos-swap swap      swap    defaults        0 0

#如果是克隆的虚拟机,需要删除UUID   很重要
重启服务器

修改内核参数

修改内核参数,在kaivimaster1、kaivimaster2、kaivimaster3、kaivinode1上操作:

#加载br_netfilter模块
modprobe br_netfilter

#验证模块是否加载成功:
lsmod |grep br_netfilter

#修改内核参数
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

#使刚才修改的内核参数生效
sysctl -p /etc/sysctl.d/k8s.conf  

问题1:sysctl是做什么的? 在运行时配置内核参数 -p
从指定的文件加载系统参数,如不指定即从/etc/sysctl.conf中加载

问题2:为什么要执行modprobe br_netfilter? 修改/etc/sysctl.d/k8s.conf文件,增加如下三行参数:
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1 net.ipv4.ip_forward = 1

sysctl -p /etc/sysctl.d/k8s.conf出现报错:

sysctl: cannot stat /proc/sys/net/bridge/bridge-nf-call-ip6tables: No such file or directory sysctl: cannot stat
/proc/sys/net/bridge/bridge-nf-call-iptables: No such file or directory

解决方法: modprobe br_netfilter

问题3:为什么开启net.bridge.bridge-nf-call-iptables内核参数?
在centos下安装docker,执行docker info出现如下警告: WARNING: bridge-nf-call-iptables is disabled WARNING: bridge-nf-call-ip6tables is disabled

解决办法: vim /etc/sysctl.d/k8s.conf net.bridge.bridge-nf-call-ip6tables = 1 net.bridge.bridge-nf-call-iptables = 1

问题4:为什么要开启net.ipv4.ip_forward = 1参数?
kubeadm初始化k8s如果报错:
在这里插入图片描述
就表示没有开启ip_forward,需要开启。

net.ipv4.ip_forward是数据包转发:
出于安全考虑,Linux系统默认是禁止数据包转发的。所谓转发即当主机拥有多于一块的网卡时,其中一块收到数据包,根据数据包的目的ip地址将数据包发往本机另一块网卡,该网卡根据路由表继续发送数据包。这通常是路由器所要实现的功能。
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。

配置阿里云repo源

配置阿里云repo源,在kaivimaster1、kaivimaster2、kaivimaster3、kaivinode1上操作:
这里以 kaivimaster1服务器为例

在kaivimaster1上操作:
安装rzsz命令
[root@kaivimaster1]# yum install lrzsz -y
安装scp:
[root@kaivimaster1]#yum install openssh-clients

#备份基础repo源
[root@kaivimaster1 ~]# mkdir /root/repo.bak
[root@kaivimaster1 ~]# cd /etc/yum.repos.d/
[root@kaivimaster1]# mv * /root/repo.bak/

#下载阿里云的repo源
把CentOS-Base.repo文件上传到kaivimaster1主机的/etc/yum.repos.d/目录下
在这里插入图片描述

#配置国内阿里云docker的repo源
[root@kaivimaster1 ~]# yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo

配置时间同步

配置时间同步,在kaivimaster1、kaivimaster2、kaivimaster3、kaivinode1上操作:

#安装ntpdate命令,
#yum install ntpdate -y

#跟网络源做同步
ntpdate cn.pool.ntp.org

#把时间同步做成计划任务
crontab -e
* */1 * * * /usr/sbin/ntpdate   cn.pool.ntp.org
#查看计划任务
crontab -l  
#重启crond服务
service crond restart

安装iptables

如果用firewalld不习惯,可以安装iptables ,在kaivimaster1、kaivimaster2、kaivimaster3、kaivinode1上操作:

#安装iptables
yum install iptables-services -y

#禁用iptables
service iptables stop   && systemctl disable iptables

#清空防火墙规则
iptables -F

开启ipvs

#不开启ipvs将会使用iptables进行数据包转发,但是效率低,所以官网推荐需要开通ipvs。
#把ipvs.modules上传到kaivimaster1机器的/etc/sysconfig/modules/目录下
在这里插入图片描述

[root@kaivimaster1# chmod 755 /etc/sysconfig/modules/ipvs.modules && bash /etc/sysconfig/modules/ipvs.modules && lsmod | grep ip_vs
ip_vs_ftp              13079  0 
nf_nat                 26583  1 ip_vs_ftp
ip_vs_sed              12519  0 
ip_vs_nq               12516  0 
ip_vs_sh               12688  0 
ip_vs_dh               12688  0 
······

拷贝到其他服务器节点:kaivimaster2、kaivimaster3、kaivinode1
这里以拷贝到kaivinode1为例

[root@kaivimaster1~]# scp /etc/sysconfig/modules/ipvs.modules kaivinode1:/etc/sysconfig/modules/
[root@kaivinode1]# chmod 755 /etc/sysconfig/modules/ipvs.modules && bash /etc/sysconfig/modules/ipvs.modules && lsmod | grep ip_vs
ip_vs_ftp              13079  0 
nf_nat                 26583  1 ip_vs_ftp
ip_vs_sed              12519  0 
ip_vs_nq               12516  0 
ip_vs_sh               12688  0 
ip_vs_dh               12688  0

安装基础软件包

安装基础软件包,在kaivimaster1、kaivimaster2、kaivimaster3、kaivinode1上操作:

yum install -y yum-utils device-mapper-persistent-data lvm2 wget net-tools nfs-utils lrzsz gcc gcc-c++ make cmake libxml2-devel openssl-devel curl curl-devel unzip sudo ntp libaio-devel wget vim ncurses-devel autoconf automake zlib-devel  python-devel epel-release openssh-server socat  ipvsadm conntrack ntpdate telnet rsync

安装docker-ce

安装docker-ce,在kaivimaster1、kaivimaster2、kaivimaster3、kaivinode1上操作:

yum install docker-ce docker-ce-cli containerd.io -y 
systemctl start docker && systemctl enable docker.service && systemctl status docker

配置docker镜像加速器

配置docker镜像加速器,在kaivimaster1、kaivimaster2、kaivimaster3、kaivinode1上操作:

tee /etc/docker/daemon.json << 'EOF'
{
 "registry-mirrors":["https://rsbud4vc.mirror.aliyuncs.com","https://registry.docker-cn.com","https://docker.mirrors.ustc.edu.cn","https://dockerhub.azk8s.cn","http://hub-mirror.c.163.com","http://qtid6917.mirror.aliyuncs.com", "https://rncxm540.mirror.aliyuncs.com"],
  "exec-opts": ["native.cgroupdriver=systemd"]
} 
EOF
systemctl daemon-reload
systemctl restart docker
systemctl status docker
Active: active (running) since Wed 2021-04-21 11:37:45 CST; 25s ago

注意:
#修改docker文件驱动为systemd,默认为cgroupfs,kubelet默认使用systemd,两者必须一致才可以。

搭建etcd集群

配置etcd工作目录

#创建配置文件和证书文件存放目录
[root@kaivimaster1 ~]# mkdir -p /etc/etcd
[root@kaivimaster1 ~]# mkdir -p /etc/etcd/ssl

[root@kaivimaster2 ~]# mkdir -p /etc/etcd
[root@kaivimaster2 ~]# mkdir -p /etc/etcd/ssl

[root@kaivimaster3 ~]#  mkdir -p /etc/etcd
[root@kaivimaster3 ~]# mkdir -p /etc/etcd/ssl

安装签发证书工具cfssl

[root@kaivimaster1 ~]# mkdir /data/work -p
[root@kaivimaster1 ~]# cd /data/work/

#cfssl-certinfo_linux-amd64 、cfssljson_linux-amd64 、cfssl_linux-amd64上传到/data/work/目录下

在这里插入图片描述

[root@kaivimaster1 work]# ls
cfssl-certinfo_linux-amd64  cfssljson_linux-amd64  cfssl_linux-amd64

#把文件变成可执行权限
[root@kaivimaster1 work]# chmod +x *
[root@kaivimaster1 work]# mv cfssl_linux-amd64 /usr/local/bin/cfssl
[root@kaivimaster1 work]# mv cfssljson_linux-amd64 /usr/local/bin/cfssljson
[root@kaivimaster1 work]# mv cfssl-certinfo_linux-amd64 /usr/local/bin/cfssl-certinfo

配置ca证书

#生成ca证书请求文件
[root@kaivimaster1 work]# vim ca-csr.json 
{
  "CN": "kubernetes",
  "key": {
      "algo": "rsa",
      "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "ST": "Hubei",
      "L": "Wuhan",
      "O": "k8s",
      "OU": "system"
    }
  ],
  "ca": {
          "expiry": "87600h"
  }
}
[root@kaivimaster1 work]# cfssl gencert -initca ca-csr.json  | cfssljson -bare ca

注: CN:Common Name(公用名称),kube-apiserver 从证书中提取该字段作为请求的用户名 (User Name);浏览器使用该字段验证网站是否合法;对于 SSL证书,一般为网站域名;而对于代码签名证书则为申请单位名称;而对于客户端证书则为证书申请者的姓名。

O:Organization(单位名称),kube-apiserver 从证书中提取该字段作为请求用户所属的组 (Group);对于 SSL证书,一般为网站域名;而对于代码签名证书则为申请单位名称;而对于客户端单位证书则为证书申请者所在单位名称。
L 字段:所在城市
S 字段:所在省份
C 字段:只能是国家字母缩写,如中国:CN

#生成ca证书文件
[root@kaivimaster1 work]# vim ca-config.json 
{
  "signing": {
      "default": {
          "expiry": "87600h"
        },
      "profiles": {
          "kubernetes": {
              "usages": [
                  "signing",
                  "key encipherment",
                  "server auth",
                  "client auth"
              ],
              "expiry": "87600h"
          }
      }
  }
}

生成etcd证书

 #配置etcd证书请求,hosts的ip变成自己etcd所在节点的ip
[root@kaivimaster1 work]# vim etcd-csr.json 
{
  "CN": "etcd",
  "hosts": [
    "127.0.0.1",
    "192.168.40.180",
    "192.168.40.181",
    "192.168.40.182",
    "192.168.40.199"
  ],
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [{
    "C": "CN",
    "ST": "Hubei",
    "L": "Wuhan",
    "O": "k8s",
    "OU": "system"
  }]
} 

#上述文件hosts字段中IP为所有etcd节点的集群内部通信IP,可以预留几个,做扩容用。

[root@kaivimaster1 work]# cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes etcd-csr.json | cfssljson  -bare etcd

[root@kaivimaster1 work]# ls etcd*.pem
etcd-key.pem  etcd.pem

部署etcd集群

把etcd-v3.4.13-linux-amd64.tar.gz上传到/data/work目录下

在这里插入图片描述

[root@kaivimaster1 work]# pwd
/data/work
[root@kaivimaster1 work]# tar -xf etcd-v3.4.13-linux-amd64.tar.gz
[root@kaivimaster1 work]# cp -p etcd-v3.4.13-linux-amd64/etcd* /usr/local/bin/
[root@kaivimaster1 work]# scp -r  etcd-v3.4.13-linux-amd64/etcd* kaivimaster2:/usr/local/bin/
[root@kaivimaster1 work]# scp -r  etcd-v3.4.13-linux-amd64/etcd* kaivimaster3:/usr/local/bin/
#创建配置文件
[root@kaivimaster1 work]# vim etcd.conf 
#[Member]
ETCD_NAME="etcd1"
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="https://192.168.40.180:2380"
ETCD_LISTEN_CLIENT_URLS="https://192.168.40.180:2379,http://127.0.0.1:2379"
#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://192.168.40.180:2380"
ETCD_ADVERTISE_CLIENT_URLS="https://192.168.40.180:2379"
ETCD_INITIAL_CLUSTER="etcd1=https://192.168.40.180:2380,etcd2=https://192.168.40.181:2380,etcd3=https://192.168.40.182:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"

#注:
ETCD_NAME:节点名称,集群中唯一
ETCD_DATA_DIR:数据目录
ETCD_LISTEN_PEER_URLS:集群通信监听地址
ETCD_LISTEN_CLIENT_URLS:客户端访问监听地址
ETCD_INITIAL_ADVERTISE_PEER_URLS:集群通告地址
ETCD_ADVERTISE_CLIENT_URLS:客户端通告地址
ETCD_INITIAL_CLUSTER:集群节点地址
ETCD_INITIAL_CLUSTER_TOKEN:集群Token
ETCD_INITIAL_CLUSTER_STATE:加入集群的当前状态,new是新集群,existing表示加入已有集群

#创建启动服务文件
[root@kaivimaster1 work]# vim etcd.service 
[Unit]
Description=Etcd Server
After=network.target
After=network-online.target
Wants=network-online.target
 
[Service]
Type=notify
EnvironmentFile=-/etc/etcd/etcd.conf
WorkingDirectory=/var/lib/etcd/
ExecStart=/usr/local/bin/etcd \
  --cert-file=/etc/etcd/ssl/etcd.pem \
  --key-file=/etc/etcd/ssl/etcd-key.pem \
  --trusted-ca-file=/etc/etcd/ssl/ca.pem \
  --peer-cert-file=/etc/etcd/ssl/etcd.pem \
  --peer-key-file=/etc/etcd/ssl/etcd-key.pem \
  --peer-trusted-ca-file=/etc/etcd/ssl/ca.pem \
  --peer-client-cert-auth \
  --client-cert-auth
Restart=on-failure
RestartSec=5
LimitNOFILE=65536
 
[Install]
WantedBy=multi-user.target

拷贝文件到其他ETCD集群节点

[root@kaivimaster1 work]# cp ca*.pem /etc/etcd/ssl/
[root@kaivimaster1 work]# cp etcd*.pem /etc/etcd/ssl/
[root@kaivimaster1 work]# cp etcd.conf /etc/etcd/
[root@kaivimaster1 work]# cp etcd.service /usr/lib/systemd/system/

[root@kaivimaster1 work]# for i in kaivimaster2 kaivimaster3;do rsync -vaz etcd.conf $i:/etc/etcd/;done
[root@kaivimaster1 work]# for i in kaivimaster2 kaivimaster3;do rsync -vaz etcd*.pem ca*.pem $i:/etc/etcd/ssl/;done
[root@kaivimaster1 work]# for i in kaivimaster2 kaivimaster3;do rsync -vaz etcd.service $i:/usr/lib/systemd/system/;done
#启动etcd集群
[root@kaivimaster1 work]# mkdir -p /var/lib/etcd/default.etcd
[root@kaivimaster2 work]# mkdir -p /var/lib/etcd/default.etcd
[root@kaivimaster3 work]# mkdir -p /var/lib/etcd/default.etcd

其他的2台ETCD集群节点配置文件,注意修改对应的IP

[root@kaivimaster2 ~]# vim /etc/etcd/etcd.conf 
#[Member]
ETCD_NAME="etcd2"
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="https://192.168.40.181:2380"
ETCD_LISTEN_CLIENT_URLS="https://192.168.40.181:2379,http://127.0.0.1:2379"
#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://192.168.40.181:2380"
ETCD_ADVERTISE_CLIENT_URLS="https://192.168.40.181:2379"
ETCD_INITIAL_CLUSTER="etcd1=https://192.168.40.180:2380,etcd2=https://192.168.40.181:2380,etcd3=https://192.168.40.182:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"

[root@kaivimaster3 ~]# vim /etc/etcd/etcd.conf 
#[Member]
ETCD_NAME="etcd3"
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="https://192.168.40.182:2380"
ETCD_LISTEN_CLIENT_URLS="https://192.168.40.182:2379,http://127.0.0.1:2379"
#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://192.168.40.182:2380"
ETCD_ADVERTISE_CLIENT_URLS="https://192.168.40.182:2379"
ETCD_INITIAL_CLUSTER="etcd1=https://192.168.40.180:2380,etcd2=https://192.168.40.181:2380,etcd3=https://192.168.40.182:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"
[root@kaivimaster1 work]# systemctl daemon-reload
[root@kaivimaster1 work]# systemctl enable etcd.service
[root@kaivimaster1 work]# systemctl start etcd.service

[root@kaivimaster2 work]# systemctl daemon-reload
[root@kaivimaster2 work]# systemctl enable etcd.service
[root@kaivimaster2 work]# systemctl start etcd.service

启动etcd的时候,先启动kaivimaster1的etcd服务,会一直卡住在启动的状态,然后接着再启动kaivimaster2的etcd,这样kaivimaster1这个节点etcd才会正常起来

[root@kaivimaster3 work]# systemctl daemon-reload
[root@kaivimaster3 work]# systemctl enable etcd.service
[root@kaivimaster3 work]# systemctl start etcd.service

[root@kaivimaster1]# systemctl status etcd
[root@kaivimaster2]# systemctl status etcd
[root@kaivimaster3]# systemctl status etcd

查看etcd集群

[root@kaivimaster1 work]# ETCDCTL_API=3
[root@kaivimaster1 ~]# /usr/local/bin/etcdctl --write-out=table --cacert=/etc/etcd/ssl/ca.pem --cert=/etc/etcd/ssl/etcd.pem --key=/etc/etcd/ssl/etcd-key.pem --endpoints=https://192.168.40.180:2379,https://192.168.40.181:2379,https://192.168.40.182:2379  endpoint health
+----------------------------+--------+-------------+-------+
|          ENDPOINT           | HEALTH |    TOOK     | ERROR |
+----------------------------+--------+-------------+-------+
| https://192.168.40.180:2379 |   true | 12.614205ms |       |
| https://192.168.40.181:2379 |   true | 15.762435ms |       |
| https://192.168.40.182:2379 |   true | 76.066459ms |       |
+----------------------------+---------+-------------+-----+ |

安装kubernetes组件

下载安装包

https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG/

把kubernetes-server-linux-amd64.tar.gz上传到kaivimaster1上的/data/work目录下:
在这里插入图片描述

[root@kaivimaster1 work]# tar zxvf kubernetes-server-linux-amd64.tar.gz
[root@kaivimaster1 work]# cd kubernetes/server/bin/
[root@kaivimaster1 bin]# cp kube-apiserver kube-controller-manager kube-scheduler kubectl /usr/local/bin/
[root@kaivimaster1 bin]# rsync -vaz kube-apiserver kube-controller-manager kube-scheduler kubectl kaivimaster2:/usr/local/bin/
[root@kaivimaster1 bin]# rsync -vaz kube-apiserver kube-controller-manager kube-scheduler kubectl kaivimaster3:/usr/local/bin/

[root@kaivimaster1 bin]# scp kubelet kube-proxy kaivinode1:/usr/local/bin/
[root@kaivimaster1 bin]# cd /data/work/
[root@kaivimaster1 work]# mkdir -p /etc/kubernetes/ 
[root@kaivimaster1 work]# mkdir -p /etc/kubernetes/ssl
[root@kaivimaster1 work]# mkdir /var/log/kubernetes

部署apiserver组件

#启动TLS Bootstrapping 机制
Master apiserver启用TLS认证后,每个节点的 kubelet 组件都要使用由 apiserver 使用的 CA 签发的有效证书才能与 apiserver 通讯,当Node节点很多时,这种客户端证书颁发需要大量工作,同样也会增加集群扩展复杂度。

为了简化流程,Kubernetes引入了TLS bootstraping机制来自动颁发客户端证书,kubelet会以一个低权限用户自动向apiserver申请证书,kubelet的证书由apiserver动态签署。

Bootstrap 是很多系统中都存在的程序,比如 Linux 的bootstrap,bootstrap 一般都是作为预先配置在开启或者系统启动的时候加载,这可以用来生成一个指定环境。Kubernetes 的 kubelet 在启动时同样可以加载一个这样的配置文件,这个文件的内容类似如下形式:

  apiVersion: v1
clusters: null
contexts:
- context:
    cluster: kubernetes
    user: kubelet-bootstrap
  name: default
current-context: default
kind: Config
preferences: {}
users:
- name: kubelet-bootstrap
  user: {}

TLS bootstrapping 具体引导过程
TLS 作用
TLS 的作用就是对通讯加密,防止中间人窃听;同时如果证书不信任的话根本就无法与 apiserver 建立连接,更不用提有没有权限向apiserver请求指定内容。

RBAC 作用
当 TLS 解决了通讯问题后,那么权限问题就应由 RBAC 解决(可以使用其他权限模型,如 ABAC);RBAC 中规定了一个用户或者用户组(subject)具有请求哪些 api 的权限;在配合 TLS 加密的时候,实际上 apiserver 读取客户端证书的 CN 字段作为用户名,读取 O字段作为用户组.

以上说明:
第一,想要与 apiserver 通讯就必须采用由 apiserver CA 签发的证书,这样才能形成信任关系,建立 TLS 连接;第二,可以通过证书的 CN、O 字段来提供 RBAC 所需的用户与用户组。

kubelet 首次启动流程
TLS bootstrapping 功能是让 kubelet 组件去 apiserver 申请证书,然后用于连接 apiserver;那么第一次启动时没有证书如何连接 apiserver ?

在apiserver 配置中指定了一个 token.csv 文件,该文件中是一个预设的用户配置;同时该用户的Token 和 由apiserver 的 CA签发的用户被写入了 kubelet 所使用的 bootstrap.kubeconfig 配置文件中;这样在首次请求时,kubelet 使用 bootstrap.kubeconfig 中被 apiserver CA 签发证书时信任的用户来与 apiserver 建立 TLS 通讯,使用 bootstrap.kubeconfig 中的用户 Token 来向 apiserver 声明自己的 RBAC 授权身份.

token.csv格式:
3940fd7fbb391d1b4d861ad17a1f0613,kubelet-bootstrap,10001,"system:kubelet-bootstrap"

首次启动时,可能与遇到 kubelet 报 401 无权访问 apiserver 的错误;这是因为在默认情况下,kubelet 通过 bootstrap.kubeconfig 中的预设用户 Token 声明了自己的身份,然后创建 CSR 请求;但是不要忘记这个用户在我们不处理的情况下他没任何权限的,包括创建 CSR 请求;所以需要创建一个 ClusterRoleBinding,将预设用户 kubelet-bootstrap 与内置的 ClusterRole system:node-bootstrapper 绑定到一起,使其能够发起 CSR 请求。稍后安装kubelet的时候演示。

#创建token.csv文件
[root@kaivimaster1 work]# cat > token.csv << EOF
$(head -c 16 /dev/urandom | od -An -t x | tr -d ' '),kubelet-bootstrap,10001,"system:kubelet-bootstrap"
EOF

#格式:token,用户名,UID,用户组

创建csr请求文件,替换为自己机器的IP

[root@kaivimaster1 work]# vim kube-apiserver-csr.json 
{
  "CN": "kubernetes",
  "hosts": [
    "127.0.0.1",
    "192.168.40.180",
    "192.168.40.181",
    "192.168.40.182",
    "192.168.40.183",
    "192.168.40.199",
    "10.255.0.1",
    "kubernetes",
    "kubernetes.default",
    "kubernetes.default.svc",
    "kubernetes.default.svc.cluster",
    "kubernetes.default.svc.cluster.local"
  ],
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "ST": "Hubei",
      "L": "Wuhan",
      "O": "k8s",
      "OU": "system"
    }
  ]
}

#注:
如果 hosts 字段不为空则需要指定授权使用该证书的 IP 或域名列表。 由于该证书后续被 kubernetes master 集群使用,需要将master节点的IP都填上,同时还需要填写 service 网络的首个IP。(一般是 kube-apiserver 指定的service-cluster-ip-range 网段的第一个IP,如 10.255.0.1)

#生成证书
[root@kaivimaster1 work]# cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes kube-apiserver-csr.json | cfssljson -bare kube-apiserver
#创建api-server的配置文件,替换成自己的ip
[root@kaivimaster1 work]# vim kube-apiserver.conf 
KUBE_APISERVER_OPTS="--enable-admission-plugins=NamespaceLifecycle,NodeRestriction,LimitRanger,ServiceAccount,DefaultStorageClass,ResourceQuota \
  --anonymous-auth=false \
  --bind-address=192.168.40.180 \
  --secure-port=6443 \
  --advertise-address=192.168.40.180 \
  --insecure-port=0 \
  --authorization-mode=Node,RBAC \
  --runtime-config=api/all=true \
  --enable-bootstrap-token-auth \
  --service-cluster-ip-range=10.255.0.0/16 \
  --token-auth-file=/etc/kubernetes/token.csv \
  --service-node-port-range=30000-50000 \
  --tls-cert-file=/etc/kubernetes/ssl/kube-apiserver.pem  \
  --tls-private-key-file=/etc/kubernetes/ssl/kube-apiserver-key.pem \
  --client-ca-file=/etc/kubernetes/ssl/ca.pem \
  --kubelet-client-certificate=/etc/kubernetes/ssl/kube-apiserver.pem \
  --kubelet-client-key=/etc/kubernetes/ssl/kube-apiserver-key.pem \
  --service-account-key-file=/etc/kubernetes/ssl/ca-key.pem \
  --service-account-signing-key-file=/etc/kubernetes/ssl/ca-key.pem  \
  --service-account-issuer=https://kubernetes.default.svc.cluster.local \
  --etcd-cafile=/etc/etcd/ssl/ca.pem \
  --etcd-certfile=/etc/etcd/ssl/etcd.pem \
  --etcd-keyfile=/etc/etcd/ssl/etcd-key.pem \
  --etcd-servers=https://192.168.40.180:2379,https://192.168.40.181:2379,https://192.168.40.182:2379 \
  --enable-swagger-ui=true \
  --allow-privileged=true \
  --apiserver-count=3 \
  --audit-log-maxage=30 \
  --audit-log-maxbackup=3 \
  --audit-log-maxsize=100 \
  --audit-log-path=/var/log/kube-apiserver-audit.log \
  --event-ttl=1h \
  --alsologtostderr=true \
  --logtostderr=false \
  --log-dir=/var/log/kubernetes \
  --v=4"

#注:
–logtostderr:启用日志
–v:日志等级
–log-dir:日志目录
–etcd-servers:etcd集群地址
–bind-address:监听地址
–secure-port:https安全端口
–advertise-address:集群通告地址
–allow-privileged:启用授权
–service-cluster-ip-range:Service虚拟IP地址段
–enable-admission-plugins:准入控制模块
–authorization-mode:认证授权,启用RBAC授权和节点自管理
–enable-bootstrap-token-auth:启用TLS bootstrap机制
–token-auth-file:bootstrap token文件
–service-node-port-range:Service nodeport类型默认分配端口范围
–kubelet-client-xxx:apiserver访问kubelet客户端证书
–tls-xxx-file:apiserver https证书
–etcd-xxxfile:连接Etcd集群证书 –
-audit-log-xxx:审计日志

#创建服务启动文件
[root@kaivimaster1 work]# vim kube-apiserver.service 
[Unit]
Description=Kubernetes API Server
Documentation=https://github.com/kubernetes/kubernetes
After=etcd.service
Wants=etcd.service
 
[Service]
EnvironmentFile=-/etc/kubernetes/kube-apiserver.conf
ExecStart=/usr/local/bin/kube-apiserver $KUBE_APISERVER_OPTS
Restart=on-failure
RestartSec=5
Type=notify
LimitNOFILE=65536
 
[Install]
WantedBy=multi-user.target

同步到其他节点文件

[root@kaivimaster1 work]# cp ca*.pem /etc/kubernetes/ssl
[root@kaivimaster1 work]# cp kube-apiserver*.pem /etc/kubernetes/ssl/
[root@kaivimaster1 work]# cp token.csv /etc/kubernetes/
[root@kaivimaster1 work]# cp kube-apiserver.conf /etc/kubernetes/
[root@kaivimaster1 work]# cp kube-apiserver.service /usr/lib/systemd/system/
[root@kaivimaster1 work]# rsync -vaz token.csv kaivimaster2:/etc/kubernetes/
[root@kaivimaster1 work]# rsync -vaz token.csv kaivimaster3:/etc/kubernetes/
[root@kaivimaster1 work]# rsync -vaz kube-apiserver*.pem kaivimaster2:/etc/kubernetes/ssl/
[root@kaivimaster1 work]# rsync -vaz kube-apiserver*.pem kaivimaster3:/etc/kubernetes/ssl/
[root@kaivimaster1 work]# rsync -vaz ca*.pem kaivimaster2:/etc/kubernetes/ssl/
[root@kaivimaster1 work]# rsync -vaz ca*.pem kaivimaster3:/etc/kubernetes/ssl/
[root@kaivimaster1 work]# rsync -vaz kube-apiserver.conf kaivimaster2:/etc/kubernetes/
[root@kaivimaster1 work]# rsync -vaz kube-apiserver.conf kaivimaster3:/etc/kubernetes/
[root@kaivimaster1 work]# rsync -vaz kube-apiserver.service kaivimaster2:/usr/lib/systemd/system/
[root@kaivimaster1 work]# rsync -vaz kube-apiserver.service kaivimaster3:/usr/lib/systemd/system/

注:kaivimaster2和kaivimaster3配置文件kube-apiserver.conf的IP地址修改为实际的本机IP

[root@kaivimaster2 ~]# cat /etc/kubernetes/kube-apiserver.conf 
KUBE_APISERVER_OPTS="--enable-admission-plugins=NamespaceLifecycle,NodeRestriction,LimitRanger,ServiceAccount,DefaultStorageClass,ResourceQuota \
  --anonymous-auth=false \
  --bind-address=192.168.40.181 \
  --secure-port=6443 \
  --advertise-address=192.168.40.181 \
  --insecure-port=0 \
  --authorization-mode=Node,RBAC \
  --runtime-config=api/all=true \
  --enable-bootstrap-token-auth \
  --service-cluster-ip-range=10.255.0.0/16 \
  --token-auth-file=/etc/kubernetes/token.csv \
  --service-node-port-range=30000-50000 \
  --tls-cert-file=/etc/kubernetes/ssl/kube-apiserver.pem  \
  --tls-private-key-file=/etc/kubernetes/ssl/kube-apiserver-key.pem \
  --client-ca-file=/etc/kubernetes/ssl/ca.pem \
  --kubelet-client-certificate=/etc/kubernetes/ssl/kube-apiserver.pem \
  --kubelet-client-key=/etc/kubernetes/ssl/kube-apiserver-key.pem \
  --service-account-key-file=/etc/kubernetes/ssl/ca-key.pem \
  --service-account-signing-key-file=/etc/kubernetes/ssl/ca-key.pem  \
  --service-account-issuer=https://kubernetes.default.svc.cluster.local \
  --etcd-cafile=/etc/etcd/ssl/ca.pem \
  --etcd-certfile=/etc/etcd/ssl/etcd.pem \
  --etcd-keyfile=/etc/etcd/ssl/etcd-key.pem \
  --etcd-servers=https://192.168.40.180:2379,https://192.168.40.181:2379,https://192.168.40.182:2379 \
  --enable-swagger-ui=true \
  --allow-privileged=true \
  --apiserver-count=3 \
  --audit-log-maxage=30 \
  --audit-log-maxbackup=3 \
  --audit-log-maxsize=100 \
  --audit-log-path=/var/log/kube-apiserver-audit.log \
  --event-ttl=1h \
  --alsologtostderr=true \
  --logtostderr=false \
  --log-dir=/var/log/kubernetes \
  --v=4"
[root@kaivimaster3 ~]# cat /etc/kubernetes/kube-apiserver.conf 
KUBE_APISERVER_OPTS="--enable-admission-plugins=NamespaceLifecycle,NodeRestriction,LimitRanger,ServiceAccount,DefaultStorageClass,ResourceQuota \
  --anonymous-auth=false \
  --bind-address=192.168.40.182 \
  --secure-port=6443 \
  --advertise-address=192.168.40.182 \
  --insecure-port=0 \
  --authorization-mode=Node,RBAC \
  --runtime-config=api/all=true \
  --enable-bootstrap-token-auth \
  --service-cluster-ip-range=10.255.0.0/16 \
  --token-auth-file=/etc/kubernetes/token.csv \
  --service-node-port-range=30000-50000 \
  --tls-cert-file=/etc/kubernetes/ssl/kube-apiserver.pem  \
  --tls-private-key-file=/etc/kubernetes/ssl/kube-apiserver-key.pem \
  --client-ca-file=/etc/kubernetes/ssl/ca.pem \
  --kubelet-client-certificate=/etc/kubernetes/ssl/kube-apiserver.pem \
  --kubelet-client-key=/etc/kubernetes/ssl/kube-apiserver-key.pem \
  --service-account-key-file=/etc/kubernetes/ssl/ca-key.pem \
  --service-account-signing-key-file=/etc/kubernetes/ssl/ca-key.pem  \
  --service-account-issuer=https://kubernetes.default.svc.cluster.local \
  --etcd-cafile=/etc/etcd/ssl/ca.pem \
  --etcd-certfile=/etc/etcd/ssl/etcd.pem \
  --etcd-keyfile=/etc/etcd/ssl/etcd-key.pem \
  --etcd-servers=https://192.168.40.180:2379,https://192.168.40.181:2379,https://192.168.40.182:2379 \
  --enable-swagger-ui=true \
  --allow-privileged=true \
  --apiserver-count=3 \
  --audit-log-maxage=30 \
  --audit-log-maxbackup=3 \
  --audit-log-maxsize=100 \
  --audit-log-path=/var/log/kube-apiserver-audit.log \
  --event-ttl=1h \
  --alsologtostderr=true \
  --logtostderr=false \
  --log-dir=/var/log/kubernetes \
  --v=4"

启动服务

[root@kaivimaster1 work]# systemctl daemon-reload
[root@kaivimaster2 work]# systemctl daemon-reload
[root@kaivimaster3 work]# systemctl daemon-reload

[root@kaivimaster1 work]# systemctl enable kube-apiserver
[root@kaivimaster2 work]# systemctl enable kube-apiserver
[root@kaivimaster3 work]# systemctl enable kube-apiserver

[root@kaivimaster1 work]# systemctl start kube-apiserver
[root@kaivimaster2 work]# systemctl start kube-apiserver
[root@kaivimaster3 work]# systemctl start kube-apiserver

[root@kaivimaster1 work]#  systemctl status kube-apiserver
   Active: active (running) since Wed 
[root@kaivimaster2 work]#  systemctl status kube-apiserver
   Active: active (running) since Wed 
[root@kaivimaster3 work]#  systemctl status kube-apiserver
   Active: active (running) since Wed 

验证

[root@kaivimaster1 work]#  curl --insecure https://192.168.40.180:6443/
{
  "kind": "Status",
  "apiVersion": "v1",
  "metadata": {
    
  },
  "status": "Failure",
  "message": "Unauthorized",
  "reason": "Unauthorized",
  "code": 401
}

上面看到401,这个是正常的的状态,还没认证

部署kubectl组件

Kubectl是客户端工具,操作k8s资源的,如增删改查等。
Kubectl操作资源的时候,怎么知道连接到哪个集群,需要一个文件/etc/kubernetes/admin.conf,kubectl会根据这个文件的配置,去访问k8s资源。/etc/kubernetes/admin.con文件记录了访问的k8s集群,和用到的证书。

可以设置一个环境变量KUBECONFIG

[root@ kaivimaster1 ~]# export KUBECONFIG =/etc/kubernetes/admin.conf

这样在操作kubectl,就会自动加载KUBECONFIG来操作要管理哪个集群的k8s资源了

也可以按照下面方法,这个是在kubeadm初始化k8s的时候会告诉我们要用的一个方法

[root@ kaivimaster1 ~]# cp /etc/kubernetes/admin.conf /root/.kube/config

这样我们在执行kubectl,就会加载/root/.kube/config文件,去操作k8s资源了

如果设置了KUBECONFIG,那就会先找到KUBECONFIG去操作k8s,如果没有KUBECONFIG变量,那就会使用/root/.kube/config文件决定管理哪个k8s集群的资源

#创建csr请求文件

[root@kaivimaster1 work]# vim admin-csr.json 
{
  "CN": "admin",
  "hosts": [],
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "ST": "Hubei",
      "L": "Wuhan",
      "O": "system:masters",             
      "OU": "system"
    }
  ]
}

#说明:
后续 kube-apiserver 使用 RBAC 对客户端(如 kubelet、kube-proxy、Pod)请求进行授权; kube-apiserver 预定义了一些 RBAC 使用的 RoleBindings,如 cluster-admin 将 Group system:masters 与 Role cluster-admin 绑定,该 Role 授予了调用kube-apiserver 的所有 API的权限; O指定该证书的 Group 为 system:masters,kubelet 使用该证书访问 kube-apiserver 时 ,由于证书被 CA 签名,所以认证通过,同时由于证书用户组为经过预授权的 system:masters,所以被授予访问所有 API 的权限;

注: 这个admin 证书,是将来生成管理员用的kube config 配置文件用的,现在我们一般建议使用RBAC 来对kubernetes 进行角色权限控制, kubernetes 将证书中的CN 字段 作为User, O 字段作为 Group; “O”: “system:masters”, 必须是system:masters,否则后面kubectl create clusterrolebinding报错。

#证书O配置为system:masters 在集群内部cluster-admin的clusterrolebinding将system:masters组和cluster-admin clusterrole绑定在一起

#生成证书
[root@kaivimaster1 work]# cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes admin-csr.json | cfssljson -bare admin
[root@kaivimaster1 work]# cp admin*.pem /etc/kubernetes/ssl/

配置安全上下文
#创建kubeconfig配置文件,比较重要
kubeconfig 为 kubectl 的配置文件,包含访问 apiserver 的所有信息,如 apiserver 地址、CA 证书和自身使用的证书(这里如果报错找不到kubeconfig路径,请手动复制到相应路径下,没有则忽略)

1.设置集群参数

[root@kaivimaster1 work]# kubectl config set-cluster kubernetes --certificate-authority=ca.pem --embed-certs=true --server=https://192.168.40.180:6443 --kubeconfig=kube.config

#查看kube.config内容

vim kube.config

apiVersion: v1
clusters:
- cluster:
    certificate-authority-data: LS0tLS1CRUdJTiBDRVJUSUZJQ0FURS0tLS0tCk1JSUR0akNDQXA2Z0F3SUJBZ0lVRUVpcFFkbVRUbWpSYWV5MTMzdUhJRFVTV
···省略···m9ESGR0U1cvclk0UzFFTTZJSGtDb0xpV1YKQ2IrVVkzb3Fqb0lBOEFHMzhZb1BiVHlqbjVuY24vOU0vVjlkS2E4RFEya011Z3dPall6alJCTFUKLS0tLS1FTkQgQ0VSVElGSUNBVEUtLS0tLQo=
    server: https://192.168.40.180:6443
  name: kubernetes
contexts: null
current-context: ""
kind: Config
preferences: {}
users: null

2.设置客户端认证参数

[root@kaivimaster1 work]# kubectl config set-credentials admin --client-certificate=admin.pem --client-key=admin-key.pem --embed-certs=true --kubeconfig=kube.config

3.设置上下文参数

[root@kaivimaster1 work]# kubectl config set-context kubernetes --cluster=kubernetes --user=admin --kubeconfig=kube.config

4.设置当前上下文

[root@kaivimaster1 work]# kubectl config use-context kubernetes --kubeconfig=kube.config

[root@kaivimaster1 work]# mkdir ~/.kube -p
[root@kaivimaster1 work]# cp kube.config ~/.kube/config

5.授权kubernetes证书访问kubelet api权限

[root@kaivimaster1 work]# kubectl create clusterrolebinding kube-apiserver:kubelet-apis --clusterrole=system:kubelet-api-admin --user kubernetes

#查看集群组件状态

[root@kaivimaster1 work]# kubectl cluster-info
Kubernetes control plane is running at https://192.168.40.180:6443

[root@kaivimaster1 work]# kubectl get componentstatuses
Warning: v1 ComponentStatus is deprecated in v1.19+
NAME                 STATUS      MESSAGE                                                                                       ERROR
controller-manager   Unhealthy   Get "http://127.0.0.1:10252/healthz": dial tcp 127.0.0.1:10252: connect: connection refused   
scheduler            Unhealthy   Get "http://127.0.0.1:10251/healthz": dial tcp 127.0.0.1:10251: connect: connection refused   
etcd-0               Healthy     {"health":"true"}                                                                             
etcd-2               Healthy     {"health":"true"}                                                                             
etcd-1               Healthy     {"health":"true"}

[root@kaivimaster1 work]# kubectl get all --all-namespaces
NAMESPACE   NAME                 TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)   AGE
default     service/kubernetes   ClusterIP   10.255.0.1   <none>        443/TCP 

#同步kubectl文件到其他节点

[root@kaivimaster2 ~]# mkdir /root/.kube/
[root@kaivimaster3 ~]#  mkdir /root/.kube/

[root@kaivimaster1 work]# rsync -vaz /root/.kube/config kaivimaster2:/root/.kube/
[root@kaivimaster1 work]# rsync -vaz /root/.kube/config kaivimaster3:/root/.kube/
  

配置kubectl子命令补全

[root@kaivimaster1 work]# yum install -y bash-completion
[root@kaivimaster1 work]# source /usr/share/bash-completion/bash_completion
[root@kaivimaster1 work]# source <(kubectl completion bash)
[root@kaivimaster1 work]# kubectl completion bash > ~/.kube/completion.bash.inc
[root@kaivimaster1 work]# source '/root/.kube/completion.bash.inc'
[root@kaivimaster1 work]# source $HOME/.bash_profile

Kubectl官方备忘单:
https://kubernetes.io/zh/docs/reference/kubectl/cheatsheet/

部署kube-controller-manager组件

#创建csr请求文件
[root@kaivimaster1 work]# vim kube-controller-manager-csr.json 
{
    "CN": "system:kube-controller-manager",
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "hosts": [
      "127.0.0.1",
      "192.168.40.180",
      "192.168.40.181",
      "192.168.40.182",
      "192.168.40.199"
    ],
    "names": [
      {
        "C": "CN",
        "ST": "Hubei",
        "L": "Wuhan",
        "O": "system:kube-controller-manager",
        "OU": "system"
      }
    ]
}

注: hosts 列表包含所有 kube-controller-manager 节点 IP; CN 为 system:kube-controller-manager、O 为 system:kube-controller-manager,kubernetes 内置的 ClusterRoleBindings system:kube-controller-manager 赋予 kube-controller-manager 工作所需的权限

#生成证书

[root@kaivimaster1 work]# cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes kube-controller-manager-csr.json | cfssljson -bare kube-controller-manager

#创建kube-controller-manager的kubeconfig

1.设置集群参数
[root@kaivimaster1 work]# kubectl config set-cluster kubernetes --certificate-authority=ca.pem --embed-certs=true --server=https://192.168.40.180:6443 --kubeconfig=kube-controller-manager.kubeconfig
2.设置客户端认证参数
[root@kaivimaster1 work]# kubectl config set-credentials system:kube-controller-manager --client-certificate=kube-controller-manager.pem --client-key=kube-controller-manager-key.pem --embed-certs=true --kubeconfig=kube-controller-manager.kubeconfig
3.设置上下文参数
[root@kaivimaster1 work]# kubectl config set-context system:kube-controller-manager --cluster=kubernetes --user=system:kube-controller-manager --kubeconfig=kube-controller-manager.kubeconfig
4.设置当前上下文
[root@kaivimaster1 work]# kubectl config use-context system:kube-controller-manager --kubeconfig=kube-controller-manager.kubeconfig

#创建配置文件kube-controller-manager.conf

[root@kaivimaster1 work]# vim kube-controller-manager.conf 
KUBE_CONTROLLER_MANAGER_OPTS="--port=0 \
  --secure-port=10252 \
  --bind-address=127.0.0.1 \
  --kubeconfig=/etc/kubernetes/kube-controller-manager.kubeconfig \
  --service-cluster-ip-range=10.255.0.0/16 \
  --cluster-name=kubernetes \
  --cluster-signing-cert-file=/etc/kubernetes/ssl/ca.pem \
  --cluster-signing-key-file=/etc/kubernetes/ssl/ca-key.pem \
  --allocate-node-cidrs=true \
  --cluster-cidr=10.0.0.0/16 \
  --experimental-cluster-signing-duration=87600h \
  --root-ca-file=/etc/kubernetes/ssl/ca.pem \
  --service-account-private-key-file=/etc/kubernetes/ssl/ca-key.pem \
  --leader-elect=true \
  --feature-gates=RotateKubeletServerCertificate=true \
  --controllers=*,bootstrapsigner,tokencleaner \
  --horizontal-pod-autoscaler-use-rest-clients=true \
  --horizontal-pod-autoscaler-sync-period=10s \
  --tls-cert-file=/etc/kubernetes/ssl/kube-controller-manager.pem \
  --tls-private-key-file=/etc/kubernetes/ssl/kube-controller-manager-key.pem \
  --use-service-account-credentials=true \
  --alsologtostderr=true \
  --logtostderr=false \
  --log-dir=/var/log/kubernetes \
  --v=2"

#创建启动文件

[root@kaivimaster1 work]# vim kube-controller-manager.service 
[Unit]
Description=Kubernetes Controller Manager
Documentation=https://github.com/kubernetes/kubernetes
[Service]
EnvironmentFile=-/etc/kubernetes/kube-controller-manager.conf
ExecStart=/usr/local/bin/kube-controller-manager $KUBE_CONTROLLER_MANAGER_OPTS
Restart=on-failure
RestartSec=5
[Install]
WantedBy=multi-user.target

#启动服务

[root@kaivimaster1 work]# cp kube-controller-manager*.pem /etc/kubernetes/ssl/
[root@kaivimaster1 work]# cp kube-controller-manager.kubeconfig /etc/kubernetes/
[root@kaivimaster1 work]# cp kube-controller-manager.conf /etc/kubernetes/
[root@kaivimaster1 work]# cp kube-controller-manager.service /usr/lib/systemd/system/
[root@kaivimaster1 work]# rsync -vaz kube-controller-manager*.pem kaivimaster2:/etc/kubernetes/ssl/
[root@kaivimaster1 work]# rsync -vaz kube-controller-manager*.pem kaivimaster3:/etc/kubernetes/ssl/
[root@kaivimaster1 work]# rsync -vaz kube-controller-manager.kubeconfig kube-controller-manager.conf kaivimaster2:/etc/kubernetes/
[root@kaivimaster1 work]# rsync -vaz kube-controller-manager.kubeconfig kube-controller-manager.conf kaivimaster3:/etc/kubernetes/
[root@kaivimaster1 work]# rsync -vaz kube-controller-manager.service kaivimaster2:/usr/lib/systemd/system/
[root@kaivimaster1 work]# rsync -vaz kube-controller-manager.service kaivimaster3:/usr/lib/systemd/system/

[root@kaivimaster1 work]# systemctl daemon-reload 
[root@kaivimaster1 work]# systemctl enable kube-controller-manager
[root@kaivimaster1 work]# systemctl start kube-controller-manager
[root@kaivimaster1 work]# systemctl status kube-controller-manager
   Active: active (running) since 

[root@kaivimaster2]# systemctl daemon-reload 
[root@kaivimaster2]# systemctl enable kube-controller-manager
[root@kaivimaster2]# systemctl start kube-controller-manager
[root@kaivimaster2]# systemctl status kube-controller-manager
   Active: active (running) since 

[root@kaivimaster3]# systemctl daemon-reload 
[root@kaivimaster3]# systemctl enable kube-controller-manager
[root@kaivimaster3]# systemctl start kube-controller-manager
[root@kaivimaster3]# systemctl status kube-controller-manager
   Active: active (running) since 

部署kube-scheduler组件

#创建csr请求
[root@kaivimaster1 work]# vim kube-scheduler-csr.json 
{
    "CN": "system:kube-scheduler",
    "hosts": [
      "127.0.0.1",
      "192.168.40.180",
      "192.168.40.181",
      "192.168.40.182",
      "192.168.40.199"
    ],
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
      {
        "C": "CN",
        "ST": "Hubei",
        "L": "Wuhan",
        "O": "system:kube-scheduler",
        "OU": "system"
      }
    ]
}

注: hosts 列表包含所有 kube-scheduler 节点 IP; CN 为 system:kube-scheduler、O 为 system:kube-scheduler,kubernetes 内置的 ClusterRoleBindings system:kube-scheduler 将赋予 kube-scheduler 工作所需的权限。

#生成证书
[root@kaivimaster1 work]# cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes kube-scheduler-csr.json | cfssljson -bare kube-scheduler

#创建kube-scheduler的kubeconfig

1.设置集群参数
[root@kaivimaster1 work]# kubectl config set-cluster kubernetes --certificate-authority=ca.pem --embed-certs=true --server=https://192.168.40.180:6443 --kubeconfig=kube-scheduler.kubeconfig
2.设置客户端认证参数
[root@kaivimaster1 work]# kubectl config set-credentials system:kube-scheduler --client-certificate=kube-scheduler.pem --client-key=kube-scheduler-key.pem --embed-certs=true --kubeconfig=kube-scheduler.kubeconfig
3.设置上下文参数
[root@kaivimaster1 work]# kubectl config set-context system:kube-scheduler --cluster=kubernetes --user=system:kube-scheduler --kubeconfig=kube-scheduler.kubeconfig
4.设置当前上下文
[root@kaivimaster1 work]# kubectl config use-context system:kube-scheduler --kubeconfig=kube-scheduler.kubeconfig

#创建配置文件kube-scheduler.conf

[root@kaivimaster1 work]# vim kube-scheduler.conf 
KUBE_SCHEDULER_OPTS="--address=127.0.0.1 \
--kubeconfig=/etc/kubernetes/kube-scheduler.kubeconfig \
--leader-elect=true \
--alsologtostderr=true \
--logtostderr=false \
--log-dir=/var/log/kubernetes \
--v=2"

#创建服务启动文件

[root@kaivimaster1 work]# vim kube-scheduler.service 
[Unit]
Description=Kubernetes Scheduler
Documentation=https://github.com/kubernetes/kubernetes
 
[Service]
EnvironmentFile=-/etc/kubernetes/kube-scheduler.conf
ExecStart=/usr/local/bin/kube-scheduler $KUBE_SCHEDULER_OPTS
Restart=on-failure
RestartSec=5
 
[Install]
WantedBy=multi-user.target

#启动服务

[root@kaivimaster1 work]# cp kube-scheduler*.pem /etc/kubernetes/ssl/
[root@kaivimaster1 work]# cp kube-scheduler.kubeconfig /etc/kubernetes/
[root@kaivimaster1 work]# cp kube-scheduler.conf /etc/kubernetes/
[root@kaivimaster1 work]# cp kube-scheduler.service /usr/lib/systemd/system/
[root@kaivimaster1 work]# rsync -vaz kube-scheduler*.pem kaivimaster2:/etc/kubernetes/ssl/
[root@kaivimaster1 work]# rsync -vaz kube-scheduler*.pem kaivimaster3:/etc/kubernetes/ssl/
[root@kaivimaster1 work]# rsync -vaz kube-scheduler.kubeconfig kube-scheduler.conf kaivimaster2:/etc/kubernetes/
[root@kaivimaster1 work]# rsync -vaz kube-scheduler.kubeconfig kube-scheduler.conf kaivimaster3:/etc/kubernetes/
[root@kaivimaster1 work]# rsync -vaz kube-scheduler.service kaivimaster2:/usr/lib/systemd/system/
[root@kaivimaster1 work]# rsync -vaz kube-scheduler.service kaivimaster3:/usr/lib/systemd/system/

[root@kaivimaster1 work]# systemctl daemon-reload
[root@kaivimaster1 work]# systemctl enable kube-scheduler
[root@kaivimaster1 work]# systemctl start kube-scheduler
[root@kaivimaster1 work]# systemctl status kube-scheduler
● kube-scheduler.service - Kubernetes Scheduler
   Active: active (running) since Wed

[root@kaivimaster2]# systemctl daemon-reload
[root@kaivimaster2]# systemctl enable kube-scheduler
[root@kaivimaster2]# systemctl start kube-scheduler
[root@kaivimaster2]# systemctl status kube-scheduler
● kube-scheduler.service - Kubernetes Scheduler
   Active: active (running) since Wed

[root@kaivimaster3]# systemctl daemon-reload
[root@kaivimaster3]# systemctl enable kube-scheduler
[root@kaivimaster3]# systemctl start kube-scheduler
[root@kaivimaster3]# systemctl status kube-scheduler
● kube-scheduler.service - Kubernetes Scheduler
   Active: active (running) since Wed

部署kubelet组件

kubelet: 每个Node节点上的kubelet定期就会调用API Server的REST接口报告自身状态,API Server接收这些信息后,将节点状态信息更新到etcd中。kubelet也通过API Server监听Pod信息,从而对Node机器上的POD进行管理,如创建、删除、更新Pod

以下操作在kaivimaster1上操作
创建kubelet-bootstrap.kubeconfig

[root@kaivimaster1 work]# cd /data/work/
#取出token
[root@kaivimaster1 work]# BOOTSTRAP_TOKEN=$(awk -F "," '{print $1}' /etc/kubernetes/token.csv)

[root@kaivimaster1 work]# rm -r kubelet-bootstrap.kubeconfig
1.设置集群参数
[root@kaivimaster1 work]#  kubectl config set-cluster kubernetes --certificate-authority=ca.pem --embed-certs=true --server=https://192.168.40.180:6443 --kubeconfig=kubelet-bootstrap.kubeconfig
2.设置客户端认证参数
[root@kaivimaster1 work]# kubectl config set-credentials kubelet-bootstrap --token=${BOOTSTRAP_TOKEN} --kubeconfig=kubelet-bootstrap.kubeconfig
3.设置上下文参数
[root@kaivimaster1 work]# kubectl config set-context default --cluster=kubernetes --user=kubelet-bootstrap --kubeconfig=kubelet-bootstrap.kubeconfig
4.设置当前上下文
[root@kaivimaster1 work]# kubectl config use-context default --kubeconfig=kubelet-bootstrap.kubeconfig
5.绑定访问apiserver交互权限用户
[root@kaivimaster1 work]# kubectl create clusterrolebinding kubelet-bootstrap --clusterrole=system:node-bootstrapper --user=kubelet-bootstrap

#创建配置文件kubelet.json
“cgroupDriver”: "systemd"要和docker的驱动一致。
address替换为自己kaivinode1的IP地址。

[root@kaivimaster1 work]# vim kubelet.json 
{
  "kind": "KubeletConfiguration",
  "apiVersion": "kubelet.config.k8s.io/v1beta1",
  "authentication": {
    "x509": {
      "clientCAFile": "/etc/kubernetes/ssl/ca.pem"
    },
    "webhook": {
      "enabled": true,
      "cacheTTL": "2m0s"
    },
    "anonymous": {
      "enabled": false
    }
  },
  "authorization": {
    "mode": "Webhook",
    "webhook": {
      "cacheAuthorizedTTL": "5m0s",
      "cacheUnauthorizedTTL": "30s"
    }
  },
  "address": "192.168.40.183",
  "port": 10250,
  "readOnlyPort": 10255,
  "cgroupDriver": "systemd",
  "hairpinMode": "promiscuous-bridge",
  "serializeImagePulls": false,
  "featureGates": {
    "RotateKubeletClientCertificate": true,
    "RotateKubeletServerCertificate": true
  },
  "clusterDomain": "cluster.local.",
  "clusterDNS": ["10.255.0.2"]
}

#创建服务启动文件

[root@kaivimaster1 work]# vim kubelet.service 
[Unit]
Description=Kubernetes Kubelet
Documentation=https://github.com/kubernetes/kubernetes
After=docker.service
Requires=docker.service
[Service]
WorkingDirectory=/var/lib/kubelet
ExecStart=/usr/local/bin/kubelet \
  --bootstrap-kubeconfig=/etc/kubernetes/kubelet-bootstrap.kubeconfig \
  --cert-dir=/etc/kubernetes/ssl \
  --kubeconfig=/etc/kubernetes/kubelet.kubeconfig \
  --config=/etc/kubernetes/kubelet.json \
  --network-plugin=cni \
  --pod-infra-container-image=k8s.gcr.io/pause:3.2 \
  --alsologtostderr=true \
  --logtostderr=false \
  --log-dir=/var/log/kubernetes \
  --v=2
Restart=on-failure
RestartSec=5
 
[Install]
WantedBy=multi-user.target

#注:
–hostname-override:显示名称,集群中唯一
–network-plugin:启用CNI
–kubeconfig:空路径,会自动生成,后面用于连接apiserver
–bootstrap-kubeconfig:首次启动向apiserver申请证书
–config:配置参数文件
–cert-dir:kubelet证书生成目录
–pod-infra-container-image:管理Pod网络容器的镜像

#注:kubelete.json配置文件address改为各个节点的ip地址,在各个work节点上启动服务

[root@kaivinode1 ~]# mkdir /etc/kubernetes/ssl -p
[root@kaivimaster1 work]# scp kubelet-bootstrap.kubeconfig kubelet.json kaivinode1:/etc/kubernetes/
[root@kaivimaster1 work]# scp  ca.pem kaivinode1:/etc/kubernetes/ssl/
[root@kaivimaster1 work]# scp  kubelet.service kaivinode1:/usr/lib/systemd/system/

#启动kubelet服务
[root@kaivinode1 ~]# mkdir /var/lib/kubelet
[root@kaivinode1 ~]# mkdir /var/log/kubernetes
[root@kaivinode1 ~]#  systemctl daemon-reload
[root@kaivinode1 ~]# systemctl enable kubelet
[root@kaivinode1 ~]# systemctl start kubelet
[root@kaivinode1 ~]#  systemctl status kubelet
   Active: active (running) since 

确认kubelet服务启动成功后,接着到kaivimaster1节点上Approve一下bootstrap请求。

执行如下命令可以看到一个worker节点发送了一个 CSR 请求:

[root@kaivimaster1 work]# kubectl get csr            #处于Pending挂起状态,并且获取NAME
NAME                                                   AGE   SIGNERNAME                                    REQUESTOR           CONDITION
node-csr-SY6gROGEmH0qVZhMVhJKKWN3UaWkKKQzV8dopoIO9Uc   87s   kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Pending
[root@kaivimaster1 work]# kubectl certificate approve node-csr-SY6gROGEmH0qVZhMVhJKKWN3UaWkKKQzV8dopoIO9Uc
[root@kaivimaster1 work]# kubectl get csr
NAME                                                   AGE     SIGNERNAME                                    REQUESTOR           CONDITION
node-csr-SY6gROGEmH0qVZhMVhJKKWN3UaWkKKQzV8dopoIO9Uc   2m25s   kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Approved,Issued

[root@kaivimaster1 work]# kubectl get nodes
NAME    STATUS     ROLES    AGE   VERSION
kaivinode1   NotReady   <none>   30s   v1.20.7

#注意:STATUS是NotReady表示还没有安装网络插件

部署kube-proxy组件

#创建csr请求

[root@kaivimaster1 work]# vim kube-proxy-csr.json 
{
  "CN": "system:kube-proxy",
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "ST": "Hubei",
      "L": "Wuhan",
      "O": "k8s",
      "OU": "system"
    }
  ]
}

生成证书

[root@kaivimaster1 work]# cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes kube-proxy-csr.json | cfssljson -bare kube-proxy

#创建kubeconfig文件

1.设置集群参数
[root@kaivimaster1 work]# kubectl config set-cluster kubernetes --certificate-authority=ca.pem --embed-certs=true --server=https://192.168.40.180:6443 --kubeconfig=kube-proxy.kubeconfig
2.设置客户端认证参数
[root@kaivimaster1 work]# kubectl config set-credentials kube-proxy --client-certificate=kube-proxy.pem --client-key=kube-proxy-key.pem --embed-certs=true --kubeconfig=kube-proxy.kubeconfig
3.设置上下文参数
[root@kaivimaster1 work]# kubectl config set-context default --cluster=kubernetes --user=kube-proxy --kubeconfig=kube-proxy.kubeconfig
4.设置当前上下文
[root@kaivimaster1 work]# kubectl config use-context default --kubeconfig=kube-proxy.kubeconfig

#创建kube-proxy配置文件

[root@kaivimaster1 work]# vim kube-proxy.yaml 
apiVersion: kubeproxy.config.k8s.io/v1alpha1
bindAddress: 192.168.40.183
clientConnection:
  kubeconfig: /etc/kubernetes/kube-proxy.kubeconfig
clusterCIDR: 192.168.40.0/24
healthzBindAddress: 192.168.40.183:10256
kind: KubeProxyConfiguration
metricsBindAddress: 192.168.40.183:10249
mode: "ipvs"

#创建服务启动文件

[root@kaivimaster1 work]# vim kube-proxy.service 
[Unit]
Description=Kubernetes Kube-Proxy Server
Documentation=https://github.com/kubernetes/kubernetes
After=network.target
 
[Service]
WorkingDirectory=/var/lib/kube-proxy
ExecStart=/usr/local/bin/kube-proxy \
  --config=/etc/kubernetes/kube-proxy.yaml \
  --alsologtostderr=true \
  --logtostderr=false \
  --log-dir=/var/log/kubernetes \
  --v=2
Restart=on-failure
RestartSec=5
LimitNOFILE=65536
 
[Install]
WantedBy=multi-user.target
#拷贝到node节点
[root@kaivimaster1 work]# scp  kube-proxy.kubeconfig kube-proxy.yaml kaivinode1:/etc/kubernetes/
[root@kaivimaster1 work]#scp  kube-proxy.service kaivinode1:/usr/lib/systemd/system/
#启动服务
[root@kaivinode1 ~]# mkdir -p /var/lib/kube-proxy
[root@kaivinode1 ~]# systemctl daemon-reload
[root@kaivinode1 ~]# systemctl enable kube-proxy
[root@kaivinode1 ~]# systemctl  start kube-proxy
[root@kaivinode1 ~]# systemctl status kube-proxy
   Active: active (running) since Wed

部署calico组件

导入离线镜像压缩包
#把pause-cordns.tar.gz上传到kaivinode1节点,手动解压
在这里插入图片描述

[root@kaivinode1 ~]# docker load -i pause-cordns.tar.gz

#解压离线镜像压缩包
#把cni.tar.gz和node.tar.gz上传到kaivinode1节点,手动解压
在这里插入图片描述

[root@kaivinode1 ~]# docker load -i cni.tar.gz
[root@kaivinode1 ~]# docker load -i node.tar.gz

#把calico.yaml文件上传到kaivimaster1上的的/data/work目录
在这里插入图片描述

[root@kaivimaster1 work]# kubectl apply -f calico.yaml

[root@kaivimaster1 ~]# kubectl get pods -n kube-system
NAME                READY   STATUS    RESTARTS   AGE
calico-node-xk7n4   1/1     Running   0          13s

[root@kaivimaster1 ~]# kubectl get nodes
NAME            STATUS   ROLES    AGE   VERSION
kaivinode1   Ready    <none>   73m   v1.20.7

部署coredns组件

把coredns.yaml上传到kaivimaster1上
在这里插入图片描述

[root@kaivimaster1 ~]# kubectl apply -f coredns.yaml

[root@kaivimaster1 ~]# kubectl get pods -n kube-system
NAME                       READY   STATUS    RESTARTS   AGE
calico-node-xk7n4          1/1     Running   0          6m6s
coredns-7bf4bd64bd-dt8dq   1/1     Running   0          51s

[root@kaivimaster1 ~]# kubectl get svc -n kube-system
NAME       TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)                  AGE
kube-dns   ClusterIP   10.255.0.2   <none>        53/UDP,53/TCP,9153/TCP   12m

查看集群状态

[root@kaivimaster1 ~]# kubectl get nodes
NAME    STATUS   ROLES    AGE   VERSION
kaivinode1   Ready    <none>   38m   v1.20.7

测试k8s集群部署tomcat服务

#把tomcat.tar.gz、busybox-1-28.tar.gz、tomcat.yaml、tomcat-service.yaml上传到kaivinode1,手动解压
在这里插入图片描述

[root@kaivinode1 ~]# docker load -i tomcat.tar.gz

[root@kaivinode1 ~]# docker load -i busybox-1-28.tar.gz 

[root@kaivimaster1 ~]# kubectl apply -f tomcat.yaml

[root@kaivimaster1 ~]# kubectl get pods
NAME       READY   STATUS    RESTARTS   AGE
demo-pod   2/2     Running   0          11m

[root@kaivimaster1 ~]# kubectl apply -f tomcat-service.yaml

[root@kaivimaster1 ~]# kubectl get svc
NAME         TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)          AGE
kubernetes   ClusterIP   10.255.0.1       <none>        443/TCP          158m
tomcat       NodePort    10.255.227.179   <none>        8080:30080/TCP   19m

在浏览器访问kaivinode1(192.168.40.183)节点的ip:30080即可请求到浏览器
在这里插入图片描述

验证cordns是否正常

[root@kaivimaster1 ~]# kubectl run busybox --image busybox:1.28 --restart=Never --rm -it busybox -- sh
/ # ping www.baidu.com
PING www.baidu.com (39.156.66.18): 56 data bytes
64 bytes from 39.156.66.18: seq=0 ttl=127 time=39.3 ms
#通过上面可以看到能访问网络

/ # nslookup kubernetes.default.svc.cluster.local
Server:		10.255.0.2
Address:	10.255.0.2:53
Name:	kubernetes.default.svc.cluster.local
Address: 10.255.0.1

/ # nslookup tomcat.default.svc.cluster.local
Server:    10.255.0.2
Address 1: 10.255.0.2 kube-dns.kube-system.svc.cluster.local

Name:      tomcat.default.svc.cluster.local
Address 1: 10.255.227.179 tomcat.default.svc.cluster.local

#注意:
busybox要用指定的1.28版本,不能用最新版本,最新版本,nslookup会解析不到dns和ip,报错如下:
/ # nslookup kubernetes.default.svc.cluster.local
Server:		10.255.0.2
Address:	10.255.0.2:53
*** Can't find kubernetes.default.svc.cluster.local: No answer
*** Can't find kubernetes.default.svc.cluster.local: No answer

10.255.0.2 就是我们coreDNS的clusterIP,说明coreDNS配置好了。
解析内部Service的名称,是通过coreDNS去解析的。

keepalived+nginx实现k8s api-server高可用

下载epel.repo上传到kaivimaster1的/etc/yum.repos.d目录下,这样才能安装keepalived和nginx

wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
yum clean all
yum makecache
把epel.repo传到kaivimaster2、kaivimaster3、kaivinode1上
[root@kaivimaster1 ~]# scp /etc/yum.repos.d/epel.repo kaivimaster2:/etc/yum.repos.d/
[root@kaivimaster1 ~]# scp /etc/yum.repos.d/epel.repo kaivimaster3:/etc/yum.repos.d/
[root@kaivimaster1 ~]# scp /etc/yum.repos.d/epel.repo kaivinode1:/etc/yum.repos.d/
1、安装nginx主备:
在kaivimaster1和kaivimaster2上做nginx主备安装
[root@kaivimaster1 ~]#  yum install nginx keepalived -y
[root@kaivimaster2 ~]#  yum install nginx keepalived -y

2、修改nginx配置文件。主备一样

[root@kaivimaster1 ~]# 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 192.168.40.180:6443;   # kaivimaster1 APISERVER IP:PORT
       server 192.168.40.181:6443;   # kaivimaster2 APISERVER IP:PORT
       server 192.168.40.182:6443;   # kaivimaster3 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 / {
        }
    }
}
[root@kaivimaster2 ~]# 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 192.168.40.180:6443;   # kaivimaster1 APISERVER IP:PORT
       server 192.168.40.181:6443;   # kaivimaster2 APISERVER IP:PORT
       server 192.168.40.182:6443;   # kaivimaster3 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 / {
        }
    }
}

3、keepalive配置

主keepalived
[root@kaivimaster1 ~]# 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 ens33  # 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,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 { 
        192.168.40.199/24
    } 
    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@kaivimaster1 ~]# cat /etc/keepalived/check_nginx.sh 
#!/bin/bash
count=$(ps -ef |grep nginx | grep sbin | egrep -cv "grep|$$")
if [ "$count" -eq 0 ];then
    systemctl stop keepalived
fi
[root@kaivimaster1 ~]# chmod +x  /etc/keepalived/check_nginx.sh

备keepalive

[root@kaivimaster2 ~]# 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_BACKUP
} 

vrrp_script check_nginx {
    script "/etc/keepalived/check_nginx.sh"
}

vrrp_instance VI_1 { 
    state BACKUP 
    interface ens33
    virtual_router_id 51 # VRRP 路由 ID实例,每个实例是唯一的 
    priority 90
    advert_int 1
    authentication { 
        auth_type PASS      
        auth_pass 1111 
    }  
    virtual_ipaddress { 
        192.168.40.199/24
    } 
    track_script {
        check_nginx
    } 
}
[root@kaivimaster2 ~]# cat /etc/keepalived/check_nginx.sh 
#!/bin/bash
count=$(ps -ef |grep nginx | grep sbin | egrep -cv "grep|$$")
if [ "$count" -eq 0 ];then
    systemctl stop keepalived
fi
[root@kaivimaster2 ~]# chmod +x /etc/keepalived/check_nginx.sh

#注:keepalived根据脚本返回状态码(0为工作正常,非0不正常)判断是否故障转移。

4、启动服务:

[root@kaivimaster1 ~]# systemctl daemon-reload
[root@kaivimaster1 ~]# systemctl start nginx
[root@kaivimaster1 ~]# systemctl start keepalived
[root@kaivimaster1 ~]# systemctl enable nginx keepalived

[root@kaivimaster2 ~]# systemctl daemon-reload
[root@kaivimaster2 ~]# systemctl start nginx
[root@kaivimaster2 ~]# systemctl start keepalived
[root@kaivimaster2 ~]# systemctl enable nginx keepalived

5、测试vip是否绑定成功

[root@kaivimaster1 ~]# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:0c:29:79:9e:36 brd ff:ff:ff:ff:ff:ff
    inet 192.168.40.180/24 brd 192.168.40.255 scope global noprefixroute ens33
       valid_lft forever preferred_lft forever
    inet 192.168.40.199/24 scope global secondary ens33   ###VIP
       valid_lft forever preferred_lft forever
    inet6 fe80::b6ef:8646:1cfc:3e0c/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever

6、测试keepalived:
停掉kaivimaster1上的nginx。vip会漂移到kaivimaster2

[root@kaivimaster1 ~]# service nginx stop

目前所有的Worker Node组件连接都还是kaivimaster1 Node,如果不改为连接VIP走负载均衡器,那么Master还是单点故障。
因此接下来就是要改所有Worker Node(kubectl get node命令查看到的节点)组件配置文件,由原来192.168.40.180修改为192.168.40.199(VIP)。
在所有Worker Node执行:

[root@kaivinode1 ~]# sed -i 's#192.168.40.180:6443#192.168.40.199:16443#' /etc/kubernetes/kubelet-bootstrap.kubeconfig

[root@kaivinode1 ~]# sed -i 's#192.168.40.180:6443#192.168.40.199:16443#' /etc/kubernetes/kubelet.json

[root@kaivinode1 ~]# sed -i 's#192.168.40.180:6443#192.168.40.199:16443#' /etc/kubernetes/kubelet.kubeconfig

[root@kaivinode1 ~]# sed -i 's#192.168.40.180:6443#192.168.40.199:16443#' /etc/kubernetes/kube-proxy.yaml

[root@kaivinode1 ~]# sed -i 's#192.168.40.180:6443#192.168.40.199:16443#' /etc/kubernetes/kube-proxy.kubeconfig

[root@kaivinode1 ~]# systemctl restart kubelet kube-proxy

这样高可用集群就安装好了

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