Centos7.6部署k8s v1.16.4高可用集群(主备模式)

发布于 1月6日  约 63 分钟

一、部署环境

主机列表:

图片.png

共有7台服务器,3台control plane,3台work,1台client。
 

k8s 版本:

图片.png

二、高可用架构

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,这里使用主备模式,架构如下:

图片.png

主备模式高可用架构说明:
图片.png

  • apiserver 通过keepalived实现高可用,当某个节点故障时触发keepalived vip 转移;
  • 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、安装准备工作

control plane和work节点都执行本部分操作。

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。

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

1.2 修改hosts文件

[root@master01 ~]# cat >> /etc/hosts << EOF
172.27.34.3    master01
172.27.34.4    master02
172.27.34.5    master03
172.27.34.93   work01 
172.27.34.94   work02
172.27.34.95   work03
EOF

图片.png

2. 验证mac地址uuid

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

图片.png

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

图片.png

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

图片.png

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

图片.png

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

图片.png

6.2 将秘钥同步至master02/master03

[root@master01 ~]# ssh-copy-id -i /root/.ssh/id_rsa.pub root@172.27.34.4
[root@master01 ~]# ssh-copy-id -i /root/.ssh/id_rsa.pub root@172.27.34.5

图片.png

6.3 免密登陆测试

[root@master01 ~]# ssh 172.27.34.4
[root@master01 ~]# ssh master03

图片.png

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

四、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

图片.png

2. 设置Docker源

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

图片.png

3. 安装Docker CE

3.1 docker安装版本查看

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

图片.png

3.2 安装docker

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

image-20191231113856110
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

图片.png

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

图片.png

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

图片.png

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

图片.png

加速器配置完成

7. 验证

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

图片.png

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 https://kubernetes.io/docs/setup/cri/

五、keepalived安装

control plane节点都执行本部分操作。

1. 安装keepalived

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

图片.png

2. keepalived配置

master01上keepalived配置:

[root@master01 ~]# more /etc/keepalived/keepalived.conf 
! Configuration File for keepalived
global_defs {
   router_id master01
}
vrrp_instance VI_1 {
    state MASTER 
    interface ens160
    virtual_router_id 50
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        172.27.34.130
    }
}

master02上keepalived配置:

[root@master02 ~]# more /etc/keepalived/keepalived.conf 
! Configuration File for keepalived
global_defs {
   router_id master02
}
vrrp_instance VI_1 {
    state BACKUP 
    interface ens160
    virtual_router_id 50
    priority 90
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        172.27.34.130
    }
}

master03上keepalived配置:

[root@master03 ~]# more /etc/keepalived/keepalived.conf 
! Configuration File for keepalived
global_defs {
   router_id master03
}
vrrp_instance VI_1 {
    state BACKUP 
    interface ens160
    virtual_router_id 50
    priority 80
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        172.27.34.130
    }

3. 启动keepalived

所有control plane启动keepalived服务并设置开机启动

[root@master01 ~]# service keepalived start
[root@master01 ~]# systemctl enable keepalived

图片.png

4. VIP查看

[root@master01 ~]# ip a

图片.png

vip在master01上

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

图片.png

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

图片.png

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

图片.png

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
  - node01
  - node02
  - node03
  - 172.27.34.3
  - 172.27.34.4
  - 172.27.34.5
  - 172.27.34.93
  - 172.27.34.94
  - 172.27.34.95
  - 172.27.34.130
controlPlaneEndpoint: "172.27.34.130:6443"
networking:
  podSubnet: "10.244.0.0/16"

kubeadm.conf为初始化的配置文件

2. master初始化

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

图片.png

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 172.27.34.130:6443 --token qbwt6v.rr4hsh73gv8vrcij \
    --discovery-token-ca-cert-hash sha256:e306ffc7a126eb1f2c0cab297bbbed04f5bb464a04c05f1b0171192acbbae966 \
    --control-plane       

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

kubeadm join 172.27.34.130:6443 --token qbwt6v.rr4hsh73gv8vrcij \
    --discovery-token-ca-cert-hash sha256:e306ffc7a126eb1f2c0cab297bbbed04f5bb464a04c05f1b0171192acbbae966 

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

图片.png

3. 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

4. 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

图片.png

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节点加入集群

1. 证书分发

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   2 15:23 cert-main-master.sh
[root@master01 ~]# more cert-main-master.sh 
USER=root # customizable
CONTROL_PLANE_IPS="172.27.34.4 172.27.34.5"
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-20200102173415649

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 ~]# pwd
/root
[root@master02 ~]# ll|grep cert-other-master.sh 
-rwxr--r--  1 root root  484 1月   2 15:29 cert-other-master.sh
[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 

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   2 15:31 cert-other-master.sh
[root@master03 ~]# ./cert-other-master.sh 

2. master02加入集群

kubeadm join 172.27.34.130:6443 --token qbwt6v.rr4hsh73gv8vrcij \
    --discovery-token-ca-cert-hash sha256:e306ffc7a126eb1f2c0cab297bbbed04f5bb464a04c05f1b0171192acbbae966 \
    --control-plane

运行初始化master生成的control plane节点加入集群的命令

图片.png

3. master03加入集群

kubeadm join 172.27.34.130:6443 --token qbwt6v.rr4hsh73gv8vrcij \
    --discovery-token-ca-cert-hash sha256:e306ffc7a126eb1f2c0cab297bbbed04f5bb464a04c05f1b0171192acbbae966 \
    --control-plane

图片.png

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 

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

5. 集群节点查看

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

图片.png所有control plane节点处于ready状态,所有的系统组件也正常。

九、work节点加入集群

1. work01加入集群

kubeadm join 172.27.34.130:6443 --token qbwt6v.rr4hsh73gv8vrcij \
    --discovery-token-ca-cert-hash sha256:e306ffc7a126eb1f2c0cab297bbbed04f5bb464a04c05f1b0171192acbbae966 

运行初始化master生成的work节点加入集群的命令

图片.png

2. work02加入集群

图片.png

3. work03加入集群

图片.png

4. 集群节点查看

[root@master01 ~]# kubectl get nodes
NAME       STATUS   ROLES    AGE     VERSION
master01   Ready    master   44m     v1.16.4
master02   Ready    master   33m     v1.16.4
master03   Ready    master   23m     v1.16.4
work01     Ready    <none>   11m     v1.16.4
work02     Ready    <none>   7m50s   v1.16.4
work03     Ready    <none>   3m4s    v1.16.4

图片.png

十、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

图片.png

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

图片.png

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

图片.png

3.3 拷贝admin.conf

[root@client ~]# mkdir -p /etc/kubernetes
[root@client ~]# scp 172.27.34.3:/etc/kubernetes/admin.conf /etc/kubernetes/
[root@client ~]# echo "export KUBECONFIG=/etc/kubernetes/admin.conf" >> ~/.bash_profile
[root@client ~]# source .bash_profile 

图片.png

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 get po -o wide -n kube-system 

图片.png

十一、Dashboard搭建

本节内容都在client端完成

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

图片.png

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

图片.png

3.2 状态查看

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

图片.png

3.3 令牌查看

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

图片.png
令牌为:

eyJhbGciOiJSUzI1NiIsImtpZCI6Ikd0NHZ5X3RHZW5pNDR6WEdldmlQUWlFM3IxbGM3aEIwWW1IRUdZU1ZKdWMifQ.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.LAe7N8Q6XR3d0W8w-r3ylOKOQHyMg5UDfGOdUkko_tqzUKUtxWQHRBQkowGYg9wDn-nU9E-rkdV9coPnsnEGjRSekWLIDkSVBPcjvEd0CVRxLcRxP6AaysRescHz689rfoujyVhB4JUfw1RFp085g7yiLbaoLP6kWZjpxtUhFu-MKh1NOp7w4rT66oFKFR-_5UbU3FoetAFBmHuZ935i5afs8WbNzIkM6u9YDIztMY3RYLm9Zs4KxgpAmqUmBSlXFZNW2qg6hxBqDijW_1bc0V7qJNt_GXzPs2Jm1trZR6UU1C2NAJVmYBu9dcHYtTCgxxkWKwR0Qd2bApEUIJ5Wug

3.4 访问

请使用火狐浏览器访问:https://VIP:30001
图片.png

图片.png

接受风险
图片.png
通过令牌方式登录
图片.png

图片.png

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。

十二、集群高可用测试

本节内容都在client端完成

1. 组件所在节点查看

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

[root@master01 ~]# ip a|grep 130
    inet 172.27.34.130/32 scope global ens160
[root@client ~]# kubectl get endpoints kube-controller-manager -n kube-system -o yaml |grep holderIdentity
    control-plane.alpha.kubernetes.io/leader: '{"holderIdentity":"master01_6caf8003-052f-451d-8dce-4516825213ad","leaseDurationSeconds":15,"acquireTime":"2020-01-02T09:36:23Z","renewTime":"2020-01-03T07:57:55Z","leaderTransitions":2}'
[root@client ~]# kubectl get endpoints kube-scheduler -n kube-system -o yaml |grep holderIdentity
    control-plane.alpha.kubernetes.io/leader: '{"holderIdentity":"master01_720d65f9-e425-4058-95d7-e5478ac951f7","leaseDurationSeconds":15,"acquireTime":"2020-01-02T09:36:20Z","renewTime":"2020-01-03T07:58:03Z","leaderTransitions":2}'

图片.png

图片.png

2. master01关机

2.1 关闭master01,模拟宕机

[root@master01 ~]# init 0

2.2 各组件查看

vip飘到了master02

[root@master02 ~]# ip a|grep 130
    inet 172.27.34.130/32 scope global ens160

controller-manager和scheduler也发生了迁移

[root@client ~]# kubectl get endpoints kube-controller-manager -n kube-system -o yaml |grep holderIdentity
    control-plane.alpha.kubernetes.io/leader: '{"holderIdentity":"master02_b3353e8f-a02f-4322-bf17-2f596cd25ba5","leaseDurationSeconds":15,"acquireTime":"2020-01-03T08:04:42Z","renewTime":"2020-01-03T08:06:36Z","leaderTransitions":3}'
[root@client ~]# kubectl get endpoints kube-scheduler -n kube-system -o yaml |grep holderIdentity
    control-plane.alpha.kubernetes.io/leader: '{"holderIdentity":"master03_e0a2ec66-c415-44ae-871c-18c73258dc8f","leaseDurationSeconds":15,"acquireTime":"2020-01-03T08:04:56Z","renewTime":"2020-01-03T08:06:45Z","leaderTransitions":3}'

图片.png

2.3 集群功能性测试

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

图片.png

master01状态为NotReady

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-lnsfh   1/1     Running   0          4m44s   10.244.5.6   work03   <none>           <none>
nginx-master-75b7bfdb6b-vxfg7   1/1     Running   0          4m44s   10.244.3.3   work01   <none>           <none>
nginx-master-75b7bfdb6b-wt9kc   1/1     Running   0          4m44s   10.244.4.5   work02   <none>           <none>

图片.png

2.4 结论

当有一个control plane节点宕机时,VIP会发生漂移,集群各项功能不受影响。

3. master02关机

在关闭master01的同时关闭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 查看VIP:

[root@master03 ~]# ip a|grep 130
    inet 172.27.34.130/32 scope global ens160

vip漂移至唯一的control plane:master03

3.3 集群功能测试

[root@client ~]# kubectl get nodes
Error from server: etcdserver: request timed out
[root@client ~]# kubectl get nodes
The connection to the server 172.27.34.130:6443 was refused - did you specify the right host or port?

etcd集群崩溃,整个k8s集群也不能正常对外服务。

本文所有脚本和配置文件已上传:Centos7.6-install-k8s-v1.16.4-HA-cluster

k8s实践(十五):Centos7.6部署k8s v1.16.4高可用集群(主备模式)

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