一、部署环境

1.1 主机列表

主机名Centos版本ipdocker versionflannel versionKeepalived version主机配置备注
lvs-keepalived017.6.1810172.27.34.28//v1.3.54C4Glvs-keepalived
lvs-keepalived017.6.1810172.27.34.29//v1.3.54C4Glvs-keepalived
master017.6.1810172.27.34.3518.09.9v0.11.0/4C4Gcontrol plane
master027.6.1810172.27.34.3618.09.9v0.11.0/4C4Gcontrol plane
master037.6.1810172.27.34.3718.09.9v0.11.0/4C4Gcontrol plane
work017.6.1810172.27.34.16118.09.9//4C4Gworker nodes
work027.6.1810172.27.34.16218.09.9//4C4Gworker nodes
work037.6.1810172.27.34.16318.09.9//4C4Gworker nodes
VIP7.6.1810172.27.34.222//v1.3.54C4G在lvs-keepalived两台主机上浮动
client7.6.1810172.27.34.85///4C4Gclient

共有9台服务器,2台为lvs-keepalived集群,3台control plane集群,3台work集群,1台client。

1.2 k8s 版本

主机名kubelet versionkubeadm versionkubectl version备注
master01v1.16.4v1.16.4v1.16.4kubectl选装
master02v1.16.4v1.16.4v1.16.4kubectl选装
master03v1.16.4v1.16.4v1.16.4kubectl选装
work01v1.16.4v1.16.4v1.16.4kubectl选装
work02v1.16.4v1.16.4v1.16.4kubectl选装
work03v1.16.4v1.16.4v1.16.4kubectl选装
client//v1.16.4client

二、高可用架构

1. 架构图

本文采用kubeadm方式搭建高可用k8s集群,k8s集群的高可用实际是k8s各核心组件的高可用,这里使用集群模式(针对apiserver来讲),架构如下:

image-20200309100826283

2. 集群模式高可用架构说明

核心组件高可用模式高可用实现方式
apiserver集群lvs+keepalived
controller-manager主备leader election
scheduler主备leader election
etcd集群kubeadm
  • apiserver 通过lvs-keepalived实现高可用,vip将请求分发至各个control plane节点的apiserver组件;
  • controller-manager k8s内部通过选举方式产生领导者(由–leader-elect 选型控制,默认为true),同一时刻集群内只有一个controller-manager组件运行;
  • scheduler k8s内部通过选举方式产生领导者(由–leader-elect 选型控制,默认为true),同一时刻集群内只有一个scheduler组件运行;
  • etcd 通过运行kubeadm方式自动创建集群来实现高可用,部署的节点数为奇数,3节点方式最多容忍一台机器宕机。

三、Centos7.6安装

本文所有的服务器都为Centos7.6,Centos7.6安装详见:Centos7.6操作系统安装及优化全纪录

安装Centos时已经禁用了防火墙和selinux并设置了阿里源。

四、k8s集群安装准备工作

control plane和work节点都执行本部分操作,以master01为例记录搭建过程。

1. 配置主机名

1.1 修改主机名

[root@centos7 ~]# hostnamectl set-hostname master01
[root@centos7 ~]# more /etc/hostname             
master01

退出重新登陆即可显示新设置的主机名master01,各服务器修改为对应的主机名。

1.2 修改hosts文件

[root@master01 ~]# cat >> /etc/hosts << EOF
172.27.34.35    master01
172.27.34.36   master02
172.27.34.37    master03
172.27.34.161   work01 
172.27.34.162   work02
172.27.34.163   work03
EOF

image-20200309101133622

2. 验证mac地址uuid

[root@master01 ~]# cat /sys/class/net/ens160/address
[root@master01 ~]# cat /sys/class/dmi/id/product_uuid

image-20200309101255911

保证各节点mac和uuid唯一

3. 禁用swap

3.1 临时禁用

[root@master01 ~]# swapoff -a

3.2 永久禁用

若需要重启后也生效,在禁用swap后还需修改配置文件/etc/fstab,注释swap

[root@master01 ~]# sed -i.bak '/swap/s/^/#/' /etc/fstab

image-20200309101324503

4. 内核参数修改

本文的k8s网络使用flannel,该网络需要设置内核参数bridge-nf-call-iptables=1,修改这个参数需要系统有br_netfilter模块。

4.1 br_netfilter模块加载

查看br_netfilter模块:

[root@master01 ~]# lsmod |grep br_netfilter

如果系统没有br_netfilter模块则执行下面的新增命令,如有则忽略。

临时新增br_netfilter模块:

[root@master01 ~]# modprobe br_netfilter

该方式重启后会失效

永久新增br_netfilter模块:

[root@master01 ~]# cat > /etc/rc.sysinit << EOF
#!/bin/bash
for file in /etc/sysconfig/modules/*.modules ; do
[ -x $file ] && $file
done
EOF
[root@master01 ~]# cat > /etc/sysconfig/modules/br_netfilter.modules << EOF
modprobe br_netfilter
EOF
[root@master01 ~]# chmod 755 /etc/sysconfig/modules/br_netfilter.modules

image-20200309101351910

4.2 内核参数临时修改

[root@master01 ~]# sysctl net.bridge.bridge-nf-call-iptables=1
net.bridge.bridge-nf-call-iptables = 1
[root@master01 ~]# sysctl net.bridge.bridge-nf-call-ip6tables=1
net.bridge.bridge-nf-call-ip6tables = 1

4.3 内核参数永久修改

[root@master01 ~]# cat <<EOF >  /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
[root@master01 ~]# sysctl -p /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1

image-20200309101414595

5. 设置kubernetes源

5.1 新增kubernetes源

[root@master01 ~]# cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64/
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF
  • [] 中括号中的是repository id,唯一,用来标识不同仓库
  • name 仓库名称,自定义
  • baseurl 仓库地址
  • enable 是否启用该仓库,默认为1表示启用
  • gpgcheck 是否验证从该仓库获得程序包的合法性,1为验证
  • repo_gpgcheck 是否验证元数据的合法性 元数据就是程序包列表,1为验证
  • gpgkey=URL 数字签名的公钥文件所在位置,如果gpgcheck值为1,此处就需要指定gpgkey文件的位置,如果gpgcheck值为0就不需要此项了

5.2 更新缓存

[root@master01 ~]# yum clean all
[root@master01 ~]# yum -y makecache

6. 免密登录

配置master01到master02、master03免密登录,本步骤只在master01上执行。

6.1 创建秘钥

[root@master01 ~]# ssh-keygen -t rsa

image-20200309101451722

6.2 将秘钥同步至master02/master03

[root@master01 ~]# ssh-copy-id -i /root/.ssh/id_rsa.pub root@172.27.34.35
[root@master01 ~]# ssh-copy-id -i /root/.ssh/id_rsa.pub root@172.27.34.36

image-20200309101519776

image-20200309101535664

6.3 免密登陆测试

[root@master01 ~]# ssh 172.27.34.36
[root@master01 ~]# ssh master03

image-20200309101612630

master01可以直接登录master02和master03,不需要输入密码。

7. 服务器重启

重启各control plane和work节点。

五、Docker安装

control plane和work节点都执行本部分操作。

1. 安装依赖包

[root@master01 ~]# yum install -y yum-utils   device-mapper-persistent-data   lvm2

image-20200311145729850

2. 设置Docker源

[root@master01 ~]# yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo

image-20200309101850544

3. 安装Docker CE

3.1 docker安装版本查看

[root@master01 ~]# yum list docker-ce --showduplicates | sort -r

image-20200309162903305

3.2 安装docker

[root@master01 ~]# yum install docker-ce-18.09.9 docker-ce-cli-18.09.9 containerd.io -y

image-20200309162930299


指定安装的docker版本为18.09.9

4. 启动Docker

[root@master01 ~]# systemctl start docker
[root@master01 ~]# systemctl enable docker

image-20200309163022673

5. 命令补全

5.1 安装bash-completion

[root@master01 ~]# yum -y install bash-completion

5.2 加载bash-completion

[root@master01 ~]# source /etc/profile.d/bash_completion.sh

image-20200309163047803

6. 镜像加速

由于Docker Hub的服务器在国外,下载镜像会比较慢,可以配置镜像加速器。主要的加速器有:Docker官方提供的中国registry mirror、阿里云加速器、DaoCloud 加速器,本文以阿里加速器配置为例。

6.1 登陆阿里云容器模块

登陆地址为:https://cr.console.aliyun.com ,未注册的可以先注册阿里云账户

image-20200309163146167

6.2 配置镜像加速器

配置daemon.json文件

[root@master01 ~]# mkdir -p /etc/docker
[root@master01 ~]# tee /etc/docker/daemon.json <<-'EOF'
{
  "registry-mirrors": ["https://v16stybc.mirror.aliyuncs.com"]
}
EOF

重启服务

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

image-20200309163212089

加速器配置完成

7. 验证

[root@master01 ~]# docker --version
[root@master01 ~]# docker run hello-world

image-20200309163235352

通过查询docker版本和运行容器hello-world来验证docker是否安装成功。

8. 修改Cgroup Driver

8.1 修改daemon.json

修改daemon.json,新增‘”exec-opts”: [“native.cgroupdriver=systemd”’

[root@master01 ~]# more /etc/docker/daemon.json 
{
  "registry-mirrors": ["https://v16stybc.mirror.aliyuncs.com"],
  "exec-opts": ["native.cgroupdriver=systemd"]
}

8.2 重新加载docker

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

修改cgroupdriver是为了消除告警:
[WARNING IsDockerSystemdCheck]: detected “cgroupfs” as the Docker cgroup driver. The recommended driver is “systemd”. Please follow the guide at Container runtimes | Kubernetes

六、k8s安装

control plane和work节点都执行本部分操作

1. 版本查看

[root@master01 ~]# yum list kubelet --showduplicates | sort -r

image-20200309163328603

本文安装的kubelet版本是1.16.4,该版本支持的docker版本为1.13.1, 17.03, 17.06, 17.09, 18.06, 18.09。

2. 安装kubelet、kubeadm和kubectl

2.1 安装三个包

[root@master01 ~]# yum install -y kubelet-1.16.4 kubeadm-1.16.4 kubectl-1.16.4

image-20200309163354550

2.2 安装包说明

  • kubelet 运行在集群所有节点上,用于启动Pod和容器等对象的工具
  • kubeadm 用于初始化集群,启动集群的命令工具
  • kubectl 用于和集群通信的命令行,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

2.3 启动kubelet

启动kubelet并设置开机启动

[root@master01 ~]# systemctl enable kubelet && systemctl start kubelet

2.4 kubectl命令补全

[root@master01 ~]# echo "source <(kubectl completion bash)" >> ~/.bash_profile
[root@master01 ~]# source .bash_profile 

3. 下载镜像

3.1 镜像下载的脚本

Kubernetes几乎所有的安装组件和Docker镜像都放在goolge自己的网站上,直接访问可能会有网络问题,这里的解决办法是从阿里云镜像仓库下载镜像,拉取到本地以后改回默认的镜像tag。本文通过运行image.sh脚本方式拉取镜像。

[root@master01 ~]# more image.sh 
#!/bin/bash
url=registry.cn-hangzhou.aliyuncs.com/loong576
version=v1.16.4
images=(`kubeadm config images list --kubernetes-version=$version|awk -F '/' '{print $2}'`)
for imagename in ${images[@]} ; do
  docker pull $url/$imagename
  docker tag $url/$imagename k8s.gcr.io/$imagename
  docker rmi -f $url/$imagename
done

url为阿里云镜像仓库地址,version为安装的kubernetes版本。

3.2 下载镜像

运行脚本image.sh,下载指定版本的镜像

[root@master01 ~]# ./image.sh
[root@master01 ~]# docker images

image-20200309163431743

七、初始化Master

master01节点执行本部分操作。

1. kubeadm.conf

[root@master01 ~]# more kubeadm-config.yaml 
apiVersion: kubeadm.k8s.io/v1beta2
kind: ClusterConfiguration
kubernetesVersion: v1.16.4
apiServer:
  certSANs:    #填写所有kube-apiserver节点的hostname、IP、VIP
  - master01
  - master02
  - master03
  - work01
  - work02
  - work03
  - 172.27.34.35
  - 172.27.34.36
  - 172.27.34.37
  - 172.27.34.161
  - 172.27.34.162
  - 172.27.34.163
  - 172.27.34.222
controlPlaneEndpoint: "172.27.34.222:6443"
networking:
  podSubnet: "10.244.0.0/16"

image-20200309163452682

kubeadm.conf为初始化的配置文件

2. master01起虚ip

在master01上起虚ip:172.27.34.222

[root@master01 ~]# ifconfig ens160:2 172.27.34.222 netmask 255.255.255.0 up

image-20200309163506636

起虚ip目的是为了执行master01的初始化,待初始化完成后去掉该虚ip

3. master初始化

[root@master01 ~]# kubeadm init --config=kubeadm-config.yaml

image-20200309163545663

记录kubeadm join的输出,后面需要这个命令将work节点和其他control plane节点加入集群中。

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 172.27.34.222:6443 --token lw90fv.j1lease5jhzj9ih2 \
    --discovery-token-ca-cert-hash sha256:79575e7a39eac086e121364f79e58a33f9c9de2a4e9162ad81d0abd1958b24f4 \
    --control-plane       

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

kubeadm join 172.27.34.222:6443 --token lw90fv.j1lease5jhzj9ih2 \
    --discovery-token-ca-cert-hash sha256:79575e7a39eac086e121364f79e58a33f9c9de2a4e9162ad81d0abd1958b24f4 

初始化失败:

如果初始化失败,可执行kubeadm reset后重新初始化

[root@master01 ~]# kubeadm reset
[root@master01 ~]# rm -rf $HOME/.kube/config

image-20200309163604073

4. 加载环境变量

[root@master01 ~]# echo "export KUBECONFIG=/etc/kubernetes/admin.conf" >> ~/.bash_profile
[root@master01 ~]# source .bash_profile

本文所有操作都在root用户下执行,若为非root用户,则执行如下操作:

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

5. 安装flannel网络

在master01上新建flannel网络

[root@master01 ~]# kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/2140ac876ef134e0ed5af15c65e414cf26827915/Documentation/kube-flannel.yml

image-20200309163624376

由于网络原因,可能会安装失败,可以在文末直接下载kube-flannel.yml文件,然后再执行apply

八、control plane节点加入k8s集群

1. 证书分发

1.1 master01分发证书

在master01上运行脚本cert-main-master.sh,将证书分发至master02和master03

[root@master01 ~]# ll|grep cert-main-master.sh 
-rwxr--r--  1 root root     638 1月  16 10:25 cert-main-master.sh
[root@master01 ~]# more cert-main-master.sh
USER=root # customizable
CONTROL_PLANE_IPS="172.27.34.36 172.27.34.37"
for host in ${CONTROL_PLANE_IPS}; do
    scp /etc/kubernetes/pki/ca.crt "${USER}"@$host:
    scp /etc/kubernetes/pki/ca.key "${USER}"@$host:
    scp /etc/kubernetes/pki/sa.key "${USER}"@$host:
    scp /etc/kubernetes/pki/sa.pub "${USER}"@$host:
    scp /etc/kubernetes/pki/front-proxy-ca.crt "${USER}"@$host:
    scp /etc/kubernetes/pki/front-proxy-ca.key "${USER}"@$host:
    scp /etc/kubernetes/pki/etcd/ca.crt "${USER}"@$host:etcd-ca.crt
    # Quote this line if you are using external etcd
    scp /etc/kubernetes/pki/etcd/ca.key "${USER}"@$host:etcd-ca.key
done

image-20200309163649608

1.2 master02移动证书至指定目录

在master02上运行脚本cert-other-master.sh,将证书移至指定目录

[root@master02 ~]# more cert-other-master.sh 
USER=root # customizable
mkdir -p /etc/kubernetes/pki/etcd
mv /${USER}/ca.crt /etc/kubernetes/pki/
mv /${USER}/ca.key /etc/kubernetes/pki/
mv /${USER}/sa.pub /etc/kubernetes/pki/
mv /${USER}/sa.key /etc/kubernetes/pki/
mv /${USER}/front-proxy-ca.crt /etc/kubernetes/pki/
mv /${USER}/front-proxy-ca.key /etc/kubernetes/pki/
mv /${USER}/etcd-ca.crt /etc/kubernetes/pki/etcd/ca.crt
# Quote this line if you are using external etcd
mv /${USER}/etcd-ca.key /etc/kubernetes/pki/etcd/ca.key
[root@master02 ~]# ./cert-other-master.sh 

image-20200309163710983

1.3 master03移动证书至指定目录

在master03上也运行脚本cert-other-master.sh

[root@master03 ~]# pwd
/root
[root@master03 ~]# ll|grep cert-other-master.sh 
-rwxr--r--  1 root root  484 1月  16 10:30 cert-other-master.sh
[root@master03 ~]# ./cert-other-master.sh 

2. master02加入k8s集群

[root@master03 ~]# kubeadm join 172.27.34.222:6443 --token lw90fv.j1lease5jhzj9ih2     --discovery-token-ca-cert-hash sha256:79575e7a39eac086e121364f79e58a33f9c9de2a4e9162ad81d0abd1958b24f4     --control-plane

运行初始化master生成的control plane节点加入集群的命令

image-20200309163732020

3. master03加入k8s集群

[root@master03 ~]# kubeadm join 172.27.34.222:6443 --token 0p7rzn.fdanprq4y8na36jh     --discovery-token-ca-cert-hash sha256:fc7a828208d554329645044633159e9dc46b0597daf66769988fee8f3fc0636b     --control-plane

image-20200309163754867

4. 加载环境变量

master02和master03加载环境变量

[root@master02 ~]# scp master01:/etc/kubernetes/admin.conf /etc/kubernetes/
[root@master02 ~]# echo "export KUBECONFIG=/etc/kubernetes/admin.conf" >> ~/.bash_profile
[root@master02 ~]# source .bash_profile 
[root@master03 ~]# scp master01:/etc/kubernetes/admin.conf /etc/kubernetes/
[root@master03 ~]# echo "export KUBECONFIG=/etc/kubernetes/admin.conf" >> ~/.bash_profile
[root@master03 ~]# source .bash_profile 

image-20200309163807751

该步操作是为了在master02和master03上也能执行kubectl命令。

5. k8s集群节点查看

[root@master01 ~]# kubectl get nodes
[root@master01 ~]# kubectl get po -o wide -n kube-system 

image-20200309163832464

发现master01和master03下载flannel异常,分别在master01和master03上手动下载该镜像后正常。

[root@master01 ~]# docker pull  registry.cn-hangzhou.aliyuncs.com/loong576/flannel:v0.11.0-amd64
[root@master03 ~]# docker pull  registry.cn-hangzhou.aliyuncs.com/loong576/flannel:v0.11.0-amd64

image-20200309163932412

九、work节点加入k8s集群

1. work01加入k8s集群

[root@work01 ~]# kubeadm join 172.27.34.222:6443 --token lw90fv.j1lease5jhzj9ih2     --discovery-token-ca-cert-hash sha256:79575e7a39eac086e121364f79e58a33f9c9de2a4e9162ad81d0abd1958b24f4

运行初始化master生成的work节点加入集群的命令

image-20200309163954129

2. work02加入k8s集群

[root@work02 ~]# kubeadm join 172.27.34.222:6443 --token lw90fv.j1lease5jhzj9ih2     --discovery-token-ca-cert-hash sha256:79575e7a39eac086e121364f79e58a33f9c9de2a4e9162ad81d0abd1958b24f4

image-20200309164016933

3. work03加入k8s集群

[root@work03 ~]# kubeadm join 172.27.34.222:6443 --token lw90fv.j1lease5jhzj9ih2     --discovery-token-ca-cert-hash sha256:79575e7a39eac086e121364f79e58a33f9c9de2a4e9162ad81d0abd1958b24f4

image-20200309164037410

4. k8s集群各节点查看

[root@master01 ~]# kubectl get nodes
[root@master01 ~]# kubectl get po -o wide -n kube-system 

image-20200309164055268

十、ipvs安装

lvs-keepalived01和lvs-keepalived02都执行本操作。

1. 安装ipvs

LVS无需安装,安装的是管理工具,第一种叫ipvsadm,第二种叫keepalive。ipvsadm是通过命令行管理,而keepalive读取配置文件管理。

[root@lvs-keepalived01 ~]# yum -y install ipvsadm

image-20200309164149554

2. 加载ipvsadm模块

把ipvsadm模块加载进系统

[root@lvs-keepalived01 ~]# ipvsadm
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
[root@lvs-keepalived01 ~]# lsmod | grep ip_vs
ip_vs                 145497  0 
nf_conntrack          133095  1 ip_vs
libcrc32c              12644  3 xfs,ip_vs,nf_conntrack

image-20200309164204749

lvs相关实践详见:LVS+Keepalived+Nginx负载均衡搭建测试

十一、keepalived安装

lvs-keepalived01和lvs-keepalived02都执行本操作。

1. keepalived安装

[root@lvs-keepalived01 ~]# yum -y install keepalived

image-20200309164222695

2. keepalived配置

lvs-keepalived01配置如下:

[root@lvs-keepalived01 ~]# more /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
   router_id lvs-keepalived01   #router_id 机器标识,通常为hostname,但不一定非得是hostname。故障发生时,邮件通知会用到。
}
vrrp_instance VI_1 {            #vrrp实例定义部分
    state MASTER                #设置lvs的状态,MASTER和BACKUP两种,必须大写 
    interface ens160            #设置对外服务的接口
    virtual_router_id 100       #设置虚拟路由标示,这个标示是一个数字,同一个vrrp实例使用唯一标示 
    priority 100                #定义优先级,数字越大优先级越高,在一个vrrp——instance下,master的优先级必须大于backup
    advert_int 1                #设定master与backup负载均衡器之间同步检查的时间间隔,单位是秒
    authentication {            #设置验证类型和密码
        auth_type PASS          #主要有PASS和AH两种
        auth_pass 1111          #验证密码,同一个vrrp_instance下MASTER和BACKUP密码必须相同
    }
    virtual_ipaddress {         #设置虚拟ip地址,可以设置多个,每行一个
        172.27.34.222
    }
}
virtual_server 172.27.34.222 6443 {  #设置虚拟服务器,需要指定虚拟ip和服务端口
    delay_loop 6                     #健康检查时间间隔
    lb_algo wrr                      #负载均衡调度算法
    lb_kind DR                       #负载均衡转发规则
    #persistence_timeout 50          #设置会话保持时间,对动态网页非常有用
    protocol TCP                     #指定转发协议类型,有TCP和UDP两种
    real_server 172.27.34.35 6443 {  #配置服务器节点1,需要指定real server的真实IP地址和端口
    weight 10                        #设置权重,数字越大权重越高
    TCP_CHECK {                      #realserver的状态监测设置部分单位秒
       connect_timeout 10            #连接超时为10秒
       retry 3                       #重连次数
       delay_before_retry 3          #重试间隔
       connect_port 6443             #连接端口为6443,要和上面的保持一致
       }
    }
    real_server 172.27.34.36 6443 {  #配置服务器节点1,需要指定real server的真实IP地址和端口
    weight 10                        #设置权重,数字越大权重越高
    TCP_CHECK {                      #realserver的状态监测设置部分单位秒
       connect_timeout 10            #连接超时为10秒
       retry 3                       #重连次数
       delay_before_retry 3          #重试间隔
       connect_port 6443             #连接端口为6443,要和上面的保持一致
       }
    }
    real_server 172.27.34.37 6443 {  #配置服务器节点1,需要指定real server的真实IP地址和端口
    weight 10                        #设置权重,数字越大权重越高
    TCP_CHECK {                      #realserver的状态监测设置部分单位秒
       connect_timeout 10            #连接超时为10秒
       retry 3                       #重连次数
       delay_before_retry 3          #重试间隔
       connect_port 6443             #连接端口为6443,要和上面的保持一致
       }
    }
}

lvs-keepalived02配置如下:

[root@lvs-keepalived02 ~]# more /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
   router_id lvs-keepalived02   #router_id 机器标识,通常为hostname,但不一定非得是hostname。故障发生时,邮件通知会用到。
}
vrrp_instance VI_1 {            #vrrp实例定义部分
    state BACKUP                #设置lvs的状态,MASTER和BACKUP两种,必须大写 
    interface ens160            #设置对外服务的接口
    virtual_router_id 100       #设置虚拟路由标示,这个标示是一个数字,同一个vrrp实例使用唯一标示 
    priority 90                 #定义优先级,数字越大优先级越高,在一个vrrp——instance下,master的优先级必须大于backup
    advert_int 1                #设定master与backup负载均衡器之间同步检查的时间间隔,单位是秒
    authentication {            #设置验证类型和密码
        auth_type PASS          #主要有PASS和AH两种
        auth_pass 1111          #验证密码,同一个vrrp_instance下MASTER和BACKUP密码必须相同
    }
    virtual_ipaddress {         #设置虚拟ip地址,可以设置多个,每行一个
        172.27.34.222
    }
}
virtual_server 172.27.34.222 6443 {  #设置虚拟服务器,需要指定虚拟ip和服务端口
    delay_loop 6                     #健康检查时间间隔
    lb_algo wrr                      #负载均衡调度算法
    lb_kind DR                       #负载均衡转发规则
    #persistence_timeout 50          #设置会话保持时间,对动态网页非常有用
    protocol TCP                     #指定转发协议类型,有TCP和UDP两种
    real_server 172.27.34.35 6443 {  #配置服务器节点1,需要指定real server的真实IP地址和端口
    weight 10                        #设置权重,数字越大权重越高
    TCP_CHECK {                      #realserver的状态监测设置部分单位秒
       connect_timeout 10            #连接超时为10秒
       retry 3                       #重连次数
       delay_before_retry 3          #重试间隔
       connect_port 6443             #连接端口为6443,要和上面的保持一致
       }
    }
    real_server 172.27.34.36 6443 {  #配置服务器节点1,需要指定real server的真实IP地址和端口
    weight 10                        #设置权重,数字越大权重越高
    TCP_CHECK {                      #realserver的状态监测设置部分单位秒
       connect_timeout 10            #连接超时为10秒
       retry 3                       #重连次数
       delay_before_retry 3          #重试间隔
       connect_port 6443             #连接端口为6443,要和上面的保持一致
       }
    }
    real_server 172.27.34.37 6443 {  #配置服务器节点1,需要指定real server的真实IP地址和端口
    weight 10                        #设置权重,数字越大权重越高
    TCP_CHECK {                      #realserver的状态监测设置部分单位秒
       connect_timeout 10            #连接超时为10秒
       retry 3                       #重连次数
       delay_before_retry 3          #重试间隔
       connect_port 6443             #连接端口为6443,要和上面的保持一致
       }
    }
}

3. master01上去掉vip

[root@master01 ~]# ifconfig ens160:2 172.27.34.222 netmask 255.255.255.0 down

image-20200309164245783

master01上去掉初始化使用的ip 172.27.34.222

4. 启动keepalived

lvs-keepalived01和lvs-keepalived02都启动keepalived并设置为开机启动

[root@lvs-keepalived01 ~]# service keepalived start
Redirecting to /bin/systemctl start keepalived.service
[root@lvs-keepalived01 ~]# systemctl enable keepalived
Created symlink from /etc/systemd/system/multi-user.target.wants/keepalived.service to /usr/lib/systemd/system/keepalived.service.

5. vip查看

[root@lvs-keepalived01 ~]# ip a

image-20200309164434474

此时vip在lvs-keepalived01上

十二、control plane节点配置

control plane都执行本操作。

1. 新建realserver.sh

打开control plane所在服务器的“路由”功能、关闭“ARP查询”功能并设置回环ip,三台control plane配置相同,如下:

[root@master01 ~]# cd /etc/rc.d/init.d/
[root@master01 init.d]# more realserver.sh 
#!/bin/bash
    SNS_VIP=172.27.34.222
    case "$1" in
    start)
        ifconfig lo:0 $SNS_VIP netmask 255.255.255.255 broadcast $SNS_VIP
        /sbin/route add -host $SNS_VIP dev lo:0
        echo "1" >/proc/sys/net/ipv4/conf/lo/arp_ignore
        echo "2" >/proc/sys/net/ipv4/conf/lo/arp_announce
        echo "1" >/proc/sys/net/ipv4/conf/all/arp_ignore
        echo "2" >/proc/sys/net/ipv4/conf/all/arp_announce
        sysctl -p >/dev/null 2>&1
        echo "RealServer Start OK"
        ;;
    stop)
        ifconfig lo:0 down
        route del $SNS_VIP >/dev/null 2>&1
        echo "0" >/proc/sys/net/ipv4/conf/lo/arp_ignore
        echo "0" >/proc/sys/net/ipv4/conf/lo/arp_announce
        echo "0" >/proc/sys/net/ipv4/conf/all/arp_ignore
        echo "0" >/proc/sys/net/ipv4/conf/all/arp_announce
        echo "RealServer Stoped"
        ;;
    *)
        echo "Usage: $0 {start|stop}"
        exit 1
    esac
    exit 0

此脚本用于control plane节点绑定 VIP ,并抑制响应 VIP 的 ARP 请求。这样做的目的是为了不让关于 VIP 的 ARP 广播时,节点服务器应答( 因为control plane节点都绑定了 VIP ,如果不做设置它们会应答,就会乱套 )。

2 运行realserver.sh脚本

在所有control plane节点执行realserver.sh脚本:

[root@master01 init.d]# chmod u+x realserver.sh 
[root@master01 init.d]# /etc/rc.d/init.d/realserver.sh start
RealServer Start OK

给realserver.sh脚本授予执行权限并运行realserver.sh脚本

image-20200309164522352

3. realserver.sh开启启动

[root@master01 init.d]# sed -i '$a /etc/rc.d/init.d/realserver.sh start' /etc/rc.d/rc.local
[root@master01 init.d]# chmod u+x /etc/rc.d/rc.local 

十三、client配置

1. 设置kubernetes源

1.1 新增kubernetes源

[root@client ~]# cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64/
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF

image-20200309164547306

1.2 更新缓存

[root@client ~]# yum clean all
[root@client ~]# yum -y makecache

2. 安装kubectl

[root@client ~]# yum install -y kubectl-1.16.4

image-20200309164607902

安装版本与集群版本保持一致

3. 命令补全

3.1 安装bash-completion

[root@client ~]# yum -y install bash-completion

3.2 加载bash-completion

[root@client ~]# source /etc/profile.d/bash_completion.sh

image-20200309164627949

3.3 拷贝admin.conf

[root@client ~]# mkdir -p /etc/kubernetes
[root@client ~]# scp 172.27.34.35:/etc/kubernetes/admin.conf /etc/kubernetes/
[root@client ~]# echo "export KUBECONFIG=/etc/kubernetes/admin.conf" >> ~/.bash_profile
[root@client ~]# source .bash_profile 

3.4 加载环境变量

[root@master01 ~]# echo "source <(kubectl completion bash)" >> ~/.bash_profile
[root@master01 ~]# source .bash_profile 

4. kubectl测试

[root@client ~]# kubectl get nodes 
[root@client ~]# kubectl get cs
[root@client ~]# kubectl cluster-info 
[root@client ~]# kubectl get po -o wide -n kube-system 

image-20200309164648821

十四、Dashboard搭建

本节内容都在client节点完成。

1. 下载yaml

[root@client ~]# wget https://raw.githubusercontent.com/kubernetes/dashboard/v2.0.0-beta8/aio/deploy/recommended.yaml

如果连接超时,可以多试几次。recommended.yaml已上传,也可以在文末下载。

2. 配置yaml

2.1 修改镜像地址

[root@client ~]# sed -i 's/kubernetesui/registry.cn-hangzhou.aliyuncs.com\/loong576/g' recommended.yaml

由于默认的镜像仓库网络访问不通,故改成阿里镜像

2.2 外网访问

[root@client ~]# sed -i '/targetPort: 8443/a\ \ \ \ \ \ nodePort: 30001\n\ \ type: NodePort' recommended.yaml

配置NodePort,外部通过https://NodeIp:NodePort 访问Dashboard,此时端口为30001

2.3 新增管理员帐号

[root@client ~]# cat >> recommended.yaml << EOF
---
# ------------------- dashboard-admin ------------------- #
apiVersion: v1
kind: ServiceAccount
metadata:
  name: dashboard-admin
  namespace: kubernetes-dashboard

---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRoleBinding
metadata:
  name: dashboard-admin
subjects:
- kind: ServiceAccount
  name: dashboard-admin
  namespace: kubernetes-dashboard
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: cluster-admin

image-20200309164711264

创建超级管理员的账号用于登录Dashboard

3. 部署访问

3.1 部署Dashboard

[root@client ~]# kubectl apply -f recommended.yaml

image-20200309164726665

3.2 状态查看

[root@client ~]# kubectl get all -n kubernetes-dashboard 

image-20200309164751965

3.3 令牌查看

[root@client ~]# kubectl describe secrets -n kubernetes-dashboard dashboard-admin

image-20200309164805099


令牌为:

eyJhbGciOiJSUzI1NiIsImtpZCI6Ii1SOU1pNGswQnJCVUtCaks2TlBnMGxUdGRSdTlPS0s0MjNjUkdlNzFRVXMifQ.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.WJPzxkAGYjtq556d3HuXNh6g0sDYm2h6U_FsPDvvfhquYSccPGJ1UzX-lKxhPYyCegc603D7yFCc9zQOzpONttkue3rGdOz8KePOAHCUX7Xp_yTcJg15BPxQDDny6Lebu0fFXh_fpbU2_35nG28lRjiwKG3mV3O5uHdX5nk500RBmLkw3F054ww66hgFBfTH2HVDi1jOlAKWC0xatdxuqp2JkMqiBCZ_8Zwhi66EQYAMT1xu8Sn5-ur_6QsgaNNYhCeNxqHUiEFIZdLNu8QAnsKJJuhxxXd2KhIF6dwMvvOPG1djKCKSyNRn-SGILDucu1_6FoBG1DiNcIr90cPAtA

3.4 访问

请使用火狐浏览器访问:https://control plane ip:30001,即https://172.27.34.35/36/37:30001/

image-20200309164825977

image-20200309164846452

接受风险

image-20200309164906305


通过令牌方式登录

image-20200309164924294

登录的首页显示

image-20200309164937984

切换到命名空间kubernetes-dashboard,查看资源。

Dashboard提供了可以实现集群管理、工作负载、服务发现和负载均衡、存储、字典配置、日志视图等功能。

为了丰富dashboard的统计数据和图表,可以安装heapster组件。heapster组件实践详见:k8s实践(十一):heapster+influxdb+grafana实现kubernetes集群监

十五、k8s集群高可用测试

1. 组件所在节点查看

通过ipvsadm查看apiserver所在节点,通过leader-elect查看scheduler和controller-manager所在节点:

1.1 apiserver节点查看

在lvs-keepalived01上执行ipvsadm查看apiserver转发到的服务器

[root@lvs-keepalived01 ~]# ipvsadm -ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  172.27.34.222:6443 wrr
  -> 172.27.34.35:6443            Route   10     2          0         
  -> 172.27.34.36:6443            Route   10     2          0         
  -> 172.27.34.37:6443            Route   10     2          0  

image-20200309165006437

1.2 controller-manager和scheduler节点查看

在client节点上查看controller-manager和scheduler组件所在节点

[root@client ~]# kubectl get endpoints kube-controller-manager -n kube-system -o yaml |grep holderIdentity
    control-plane.alpha.kubernetes.io/leader: '{"holderIdentity":"master01_0a2bcea9-d17e-405b-8b28-5059ca434144","leaseDurationSeconds":15,"acquireTime":"2020-01-19T03:07:51Z","renewTime":"2020-01-19T04:40:20Z","leaderTransitions":2}'
[root@client ~]# kubectl get endpoints kube-scheduler -n kube-system -o yaml |grep holderIdentity
    control-plane.alpha.kubernetes.io/leader: '{"holderIdentity":"master01_c284cee8-57cf-46e7-a578-6c0a10aedb37","leaseDurationSeconds":15,"acquireTime":"2020-01-19T03:07:51Z","renewTime":"2020-01-19T04:40:30Z","leaderTransitions":2}'

image-20200309165022245

组件名所在节点
apiservermaster01、master02、master03
controller-managermaster01
schedulermaster01

2. master01关机

2.1 关闭master01

关闭master01,模拟宕机

[root@master01 ~]# init 0

2.2 apiserver组件节点查看

lvs-keepalived01上查看apiserver节点链接情况

[root@lvs-keepalived01 ~]# ipvsadm -ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  172.27.34.222:6443 wrr
  -> 172.27.34.36:6443            Route   10     4          0         
  -> 172.27.34.37:6443            Route   10     2          0 

image-20200309165043615

发现master01的apiserver被移除集群,即访问172.27.34.222:64443时不会被调度到master01

2.3 controller-manager和scheduler组件节点查看

client节点上再次运行查看controller-manager和scheduler命令

[root@client ~]# kubectl get endpoints kube-controller-manager -n kube-system -o yaml |grep holderIdentity
    control-plane.alpha.kubernetes.io/leader: '{"holderIdentity":"master03_9481b109-f236-432a-a2cb-8d0c27417396","leaseDurationSeconds":15,"acquireTime":"2020-01-19T04:42:22Z","renewTime":"2020-01-19T04:45:45Z","leaderTransitions":3}'
[root@client ~]# kubectl get endpoints kube-scheduler -n kube-system -o yaml |grep holderIdentity
    control-plane.alpha.kubernetes.io/leader: '{"holderIdentity":"master03_6d84981b-3ab9-4a00-a86a-47bd2f5c7729","leaseDurationSeconds":15,"acquireTime":"2020-01-19T04:42:23Z","renewTime":"2020-01-19T04:45:48Z","leaderTransitions":3}'
[root@client ~]# 

image-20200309165106862

controller-manager和scheduler都被切换到master03节点

组件名所在节点
apiservermaster02、master03
controller-managermaster03
schedulermaster03

2.4 集群功能性测试

所有功能性测试都在client节点完成。

2.4.1 查询

[root@client ~]# kubectl get nodes
NAME       STATUS     ROLES    AGE   VERSION
master01   NotReady   master   22h   v1.16.4
master02   Ready      master   22h   v1.16.4
master03   Ready      master   22h   v1.16.4
work01     Ready      <none>   22h   v1.16.4
work02     Ready      <none>   22h   v1.16.4
work03     Ready      <none>   22h   v1.16.4

image-20200309165121411

master01状态为NotReady

2.4.2 新建pod

[root@client ~]# more nginx-master.yaml 
apiVersion: apps/v1             #描述文件遵循extensions/v1beta1版本的Kubernetes API
kind: Deployment                #创建资源类型为Deployment
metadata:                       #该资源元数据
  name: nginx-master            #Deployment名称
spec:                           #Deployment的规格说明
  selector:
    matchLabels:
      app: nginx 
  replicas: 3                   #指定副本数为3
  template:                     #定义Pod的模板
    metadata:                   #定义Pod的元数据
      labels:                   #定义label(标签)
        app: nginx              #label的key和value分别为app和nginx
    spec:                       #Pod的规格说明
      containers:               
      - name: nginx             #容器的名称
        image: nginx:latest     #创建容器所使用的镜像
[root@client ~]# kubectl apply -f nginx-master.yaml 
deployment.apps/nginx-master created
[root@client ~]# kubectl get po -o wide
NAME                            READY   STATUS    RESTARTS   AGE   IP           NODE     NOMINATED NODE   READINESS GATES
nginx-master-75b7bfdb6b-9d66p   1/1     Running   0          20s   10.244.3.6   work01   <none>           <none>
nginx-master-75b7bfdb6b-h4bql   1/1     Running   0          20s   10.244.5.5   work03   <none>           <none>
nginx-master-75b7bfdb6b-zmc68   1/1     Running   0          20s   10.244.4.5   work02   <none>           <none>

image-20200309165142390

以新建pod nginx为例测试集群是否能正常对外提供服务。

2.5 结论

在3节点的k8s集群中,当有一个control plane节点宕机时,集群各项功能不受影响。

3. master02关机

在master01处于关闭状态下,继续关闭master02,测试集群还能否正常对外服务。

3.1 关闭master02

[root@master02 ~]# init 0

3.2 apiserver组件节点查看

[root@lvs-keepalived01 ~]# ipvsadm -ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  172.27.34.222:6443 wrr
  -> 172.27.34.37:6443            Route   10     6          20 

image-20200309165159752

此时对集群的访问都转到master03

3.3 集群功能测试

[root@client ~]# kubectl get nodes
The connection to the server 172.27.34.222:6443 was refused - did you specify the right host or port?

3.4 结论

在3节点的k8s集群中,当有两个control plane节点同时宕机时,etcd集群崩溃,整个k8s集群也不能正常对外服务。

十六、lvs-keepalived集群高可用测试

1. 高可用测试前检查

1.1 k8s集群检查

[root@client ~]# kubectl get nodes
NAME       STATUS   ROLES    AGE    VERSION
master01   Ready    master   161m   v1.16.4
master02   Ready    master   144m   v1.16.4
master03   Ready    master   142m   v1.16.4
work01     Ready    <none>   137m   v1.16.4
work02     Ready    <none>   135m   v1.16.4
work03     Ready    <none>   134m   v1.16.4

集群内个节点运行正常

1.2 vip查看

[root@lvs-keepalived01 ~]# ip a|grep 222
    inet 172.27.34.222/32 scope global ens160

发现vip运行在lvs-keepalived01上

1.3 链接情况

lvs-keepalived01:

[root@lvs-keepalived01 ~]# ipvsadm -ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  172.27.34.222:6443 wrr
  -> 172.27.34.35:6443            Route   10     6          0         
  -> 172.27.34.36:6443            Route   10     0          0         
  -> 172.27.34.37:6443            Route   10     38         0  

lvs-keepalived02:

[root@lvs-keepalived02 ~]# ipvsadm -ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  172.27.34.222:6443 wrr
  -> 172.27.34.35:6443            Route   10     0          0         
  -> 172.27.34.36:6443            Route   10     0          0         
  -> 172.27.34.37:6443            Route   10     0          0  

2. lvs-keepalived01关机

关闭lvs-keepalived01,模拟宕机

[root@lvs-keepalived01 ~]# init 0

2.1 k8s集群检查

[root@client ~]# kubectl get nodes
NAME       STATUS   ROLES    AGE    VERSION
master01   Ready    master   166m   v1.16.4
master02   Ready    master   148m   v1.16.4
master03   Ready    master   146m   v1.16.4
work01     Ready    <none>   141m   v1.16.4
work02     Ready    <none>   139m   v1.16.4
work03     Ready    <none>   138m   v1.16.4

集群内个节点运行正常

2.2 vip查看

[root@lvs-keepalived02 ~]# ip a|grep 222
    inet 172.27.34.222/32 scope global ens160

发现vip已漂移至lvs-keepalived02

2.3 链接情况

lvs-keepalived02:

[root@lvs-keepalived02 ~]# ipvsadm -ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  172.27.34.222:6443 wrr
  -> 172.27.34.35:6443            Route   10     1          0         
  -> 172.27.34.36:6443            Route   10     4          0         
  -> 172.27.34.37:6443            Route   10     1          0  

2.4 集群功能性测试

[root@client ~]# kubectl delete -f nginx-master.yaml 
deployment.apps "nginx-master" deleted
[root@client ~]# kubectl get po -o wide
NAME                            READY   STATUS        RESTARTS   AGE   IP           NODE     NOMINATED NODE   READINESS GATES
nginx-master-75b7bfdb6b-9d66p   0/1     Terminating   0          20m   10.244.3.6   work01   <none>           <none>
nginx-master-75b7bfdb6b-h4bql   0/1     Terminating   0          20m   10.244.5.5   work03   <none>           <none>
nginx-master-75b7bfdb6b-zmc68   0/1     Terminating   0          20m   10.244.4.5   work02   <none>           <none>
[root@client ~]# kubectl get po -o wide
No resources found in default namespace.

image-20200309165304669

删除之前新建的pod nginx,成功删除。

2.5 结论

当lvs-keepalived集群有一台宕机时,对k8s集群无影响,仍能正常对外提供服务。

Logo

K8S/Kubernetes社区为您提供最前沿的新闻资讯和知识内容

更多推荐