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Kubernetes基础之高可用集群搭建-kubeadm方式

环境说明

  • 宿主机系统: Windows 10
  • 虚拟机版本: VMware® Workstation 16 Pro
  • IOS镜像版本: CentOS Linux release 7.9.2009
  • 集群操作用户: root

CentOS7虚拟机安装和配置静态IP请参考博客文章：VMWARE WORKSTATION安装CENTOS7并配置静态IP

资源分配

网段划分

Kubernetes集群需要规划三个网段：

  • 宿主机网段：Kubernetes集群节点的网段
  • Pod网段：集群内Pod的网段，相当于容器的IP
  • Service网段：集群内服务发现使用的网段，service用于集群容器通信

生产环境根据申请到的IP资源进行分配即可，原则是三个网段不要有交叉。本文虚拟机练习环境IP地址段分配如下：

  • 宿主机网段：192.168.43.1/24
  • Pod网段：172.16.0.0/12
  • Service：10.96.0.0/12

节点分配

本次实验采用3管理节点2工作节点的高可用Kubernetes集群模式:

  • k8s-master01/k8s-master02/k8s-master03 集群的Master节点
  • 三个master节点同时做etcd集群
  • k8s-node01/k8s-node02 集群的Node节点
  • k8s-master-vip: 192.168.43.182,是做高可用k8s-master01~3的虚拟IP,不占用物理资源
主机节点名称 IP CPU核心数 内存大小 磁盘大小
k8s-master-vip 192.168.43.182 / / /
k8s-master01 192.168.43.183 2 2G 40G
k8s-master02 192.168.43.184 2 2G 40G
k8s-master03 192.168.43.185 2 2G 40G
k8s-node01 192.168.43.186 2 2G 40G
k8s-node02 192.168.43.187 2 2G 40G

操作步骤

小括号注释说明：

  • ALL 所有节点都要执行
  • Master 只需要在master节点(k8s-master01/k8s-master02/k8s-master03)执行
  • Node 只需要在node节点(k8s-node01/k8s-node02)执行

准备工作(ALL)

添加主机信息、关闭防火墙、关闭swap、关闭SELinux、dnsmasq、NetworkManager

# 以k8s-master01为例
[root@k8s-master01 ~]# cat << EOF >> /etc/hosts
192.168.43.182    k8s-master-vip
192.168.43.183    k8s-master01
192.168.43.184    k8s-master02
192.168.43.185    k8s-master03
192.168.43.186    k8s-node01
192.168.43.187    k8s-node02
EOF
# 直接执行下面命令
systemctl stop firewalld
systemctl disable firewalld
systemctl disable --now dnsmasq
systemctl disable --now NetworkManager

swapoff -a
sed -i '/swap/s/^\(.*\)$/#\1/g' /etc/fstab

setenforce 0
sed -i "s/=enforcing/=disabled/g" /etc/selinux/config

# 值得注意的是/etc/sysconfig/selinux文件是/etc/selinux/config文件的软连接，用sed -i命令修改软连接文件的话会破坏软连接属性，将/etc/sysconfig/selinux变为一个文件，即使该文件被修改了，但源文件/etc/selinux/config配置是没变的，所以推荐直接修改/etc/selinux/config中的配置，要么就直接vim编辑文件（编辑模式不会修改文件属性）修改也可以

更新源并升级内核(ALL)

# 默认的yum源太慢，更新为阿里源，同时用sed命令删除包含下面不需要的两个URL的行
curl -o /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-7.repo
sed -i -e '/mirrors.cloud.aliyuncs.com/d' -e '/mirrors.aliyuncs.com/d' /etc/yum.repos.d/CentOS-Base.repo
# 配置阿里云Kubernetes镜像源
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=http://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg
       http://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF

# 安装常用工具包（在需要时安装也可以，通常一起装了比较省事）
yum install wget jq psmisc vim net-tools telnet yum-utils device-mapper-persistent-data lvk8s-master02 git -y

# 升级内核，4.17以下的内核cgroup存在内存泄漏的BUG，具体分析过程浏览器搜一下“Kubernetes集群为什么要升级内核”会有一大波文章
cd /root
wget http://193.49.22.109/elrepo/kernel/el7/x86_64/RPMS/kernel-ml-devel-4.19.12-1.el7.elrepo.x86_64.rpm
wget http://193.49.22.109/elrepo/kernel/el7/x86_64/RPMS/kernel-ml-4.19.12-1.el7.elrepo.x86_64.rpm
# 所有节点安装内核
cd /root && yum localinstall -y kernel-ml*
# 所有节点更改内核启动顺序
grub2-set-default  0 && grub2-mkconfig -o /etc/grub2.cfg
grubby --args="user_namespace.enable=1" --update-kernel="$(grubby --default-kernel)"
# 检查默认内核是不是4.19，并重启节点
grubby --default-kernel
reboot

# 检查内核是不是4.19
uname -a
# （可选）删除老版本的内核，避免以后被升级取代默认的开机4.19内核
rpm -qa | grep kernel
yum remove -y kernel-3*

# 升级系统软件包（如果跳过内核升级加参数 --exclude=kernel*）
yum update -y

# 安装IPVS内核模块，由于IPVS在资源消耗和性能上均已明显优于iptables，所以推荐开启
# 具体原因可参考官网介绍 https://kubernetes.io/zh/blog/2018/07/09/ipvs-based-in-cluster-load-balancing-deep-dive/
yum install ipvsadm ipset sysstat conntrack libseccomp -y
# 加载模块，最后一条4.18以下内核使用nf_conntrack_ipv4，4.19已改为nf_conntrack
modprobe -- ip_vs
modprobe -- ip_vs_rr
modprobe -- ip_vs_wrr
modprobe -- ip_vs_sh
modprobe -- nf_conntrack
# 编写参数文件
cat << EOF > /etc/modules-load.d/ipvs.conf 
ip_vs
ip_vs_lc
ip_vs_wlc
ip_vs_rr
ip_vs_wrr
ip_vs_lblc
ip_vs_lblcr
ip_vs_dh
ip_vs_sh
ip_vs_fo
ip_vs_nq
ip_vs_sed
ip_vs_ftp
ip_vs_sh
nf_conntrack
ip_tables
ip_set
xt_set
ipt_set
ipt_rpfilter
ipt_REJECT
ipip
EOF
# 加载
systemctl enable --now systemd-modules-load.service
# 自定义内核参数配置文件
cat << EOF > /etc/sysctl.d/kubernetes.conf
net.ipv4.ip_forward = 1
net.bridge.bridge-nf-call-iptables = 1
net.bridge.bridge-nf-call-ip6tables = 1
fs.may_detach_mounts = 1
net.ipv4.conf.all.route_localnet = 1
vm.overcommit_memory=1
vm.panic_on_oom=0
fs.inotify.max_user_watches=89100
fs.file-max=52706963
fs.nr_open=52706963
net.netfilter.nf_conntrack_max=2310720
net.ipv4.tcp_keepalive_time = 600
net.ipv4.tcp_keepalive_probes = 3
net.ipv4.tcp_keepalive_intvl =15
net.ipv4.tcp_max_tw_buckets = 36000
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_max_orphans = 327680
net.ipv4.tcp_orphan_retries = 3
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_max_syn_backlog = 16384
net.ipv4.ip_conntrack_max = 65536
net.ipv4.tcp_max_syn_backlog = 16384
net.ipv4.tcp_timestamps = 0
net.core.somaxconn = 16384
EOF
# 加载
sysctl --system
# 重启查看PIVS模块是否依旧加载
reboot
lsmod | grep ip_vs

# 配置ntpdate,同步服务器时间
rpm -ivh http://mirrors.wlnmp.com/centos/wlnmp-release-centos.noarch.rpm
yum install ntpdate -y
# 同步时区和时间
ln -sf /usr/share/zoneinfo/Asia/Shanghai /etc/localtime
echo 'Asia/Shanghai' >/etc/timezone
ntpdate time2.aliyun.com

# 配置limits
cat << EOF >> /etc/security/limits.conf
* soft nofile 655360
* hard nofile 131072
* soft nproc 655350
* hard nproc 655350
* soft memlock unlimited
* hard memlock unlimited
EOF

# 配置免密登录, k8s-master01到其他节点
# 先生成认证文件
ssh-keygen -t rsa
# 拷贝公钥信息到其他节点，同时认证一次各个节点的root密码，以后就可以免密ssh到其他节点
for i in k8s-master02 k8s-master03 k8s-node01 k8s-node02;do ssh-copy-id -i .ssh/id_rsa.pub $i;done

部署Docker(ALL)

# 卸载已存在docker，新机器的话这步可以忽略
yum remove -y docker \
              docker-client \
              docker-client-latest \
              docker-common \
              docker-latest \
              docker-latest-logrotate \
              docker-logrotate \
              docker-engine

yum remove -y docker-ce docker-ce-cli containerd.io

# 设置docker仓库
yum-config-manager --add-repo https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo

# 安装最新版本docker
yum install docker-ce docker-ce-cli containerd.io -y

# （可选）如果想要安装指定版本docker，先查询一下。安装指定版本，例如20.10.9-3.el7
yum list docker-ce docker-ce-cli --showduplicates | grep "^doc" | sort -r
yum install docker-ce-20.10.9-3.el7 docker-ce-cli-20.10.9-3.el7 containerd.io -y

# 加入开机启动并启动
systemctl enable docker
systemctl start docker

# 测试运行hello-world镜像并查看docker版本信息
docker run hello-world
docker version

# 配置阿里docker镜像加速器，阿里云(登录账号-->点击管理控制台-->搜索容器镜像服务-->镜像工具-->镜像加速器-->复制加速器地址)
# docker文件驱动改成 systemd
cat <<EOF > /etc/docker/daemon.json
{
  "exec-opts": ["native.cgroupdriver=systemd"],
  "registry-mirror": ["https://ynirk4k5.mirror.aliyuncs.com"]
}
EOF

# 重启docker
systemctl restart docker
# 如果启动失败,强制加载再启动试试
systemctl reset-failed docker
systemctl restart docker

# 查看docker配置信息
docker info
docker info | grep Driver

安装kubernetes(ALL)

一般kebectl在master节点安装即可,node节点装不装均可

# 查看可以安装的版本号
yum list kubeadm --showduplicates | sort -r
# 不指定版本的话默认安装最新版本安装
yum install -y kubelet kubeadm kubectl
# 指定版本进行安装，如1.22.4
yum install -y kubelet-1.22.4 kubeadm-1.22.4 kubectl-1.22.4
# 配置pause镜像仓库，默认的gcr.io国内无法访问，可以使用阿里仓库
cat << EOF > /etc/sysconfig/kubelet
KUBELET_EXTRA_ARGS="--pod-infra-container-image=registry.cn-hangzhou.aliyuncs.com/google_containers/pause:3.5"
EOF
# 先加入开机启动
systemctl enable kubelet
# 先不启动kubelet,因为会启动失败,提示初始化文件不存在,kubernetes集群初始化完成后会启动

高可用组件安装(Master)

# 所有master节点安装Keepalived和haproxy
yum install keepalived haproxy -y
# 为所有master节点添加haproxy配置，配置都一样，检查最后三行主机名和IP地址对应上就行
mkdir /etc/haproxy
cat << EOF > /etc/haproxy/haproxy.cfg
global
  maxconn  2000
  ulimit-n  16384
  log  127.0.0.1 local0 err
  stats timeout 30s

defaults
  log global
  mode  http
  option  httplog
  timeout connect 5000
  timeout client  50000
  timeout server  50000
  timeout http-request 15s
  timeout http-keep-alive 15s

frontend monitor-in
  bind *:33305
  mode http
  option httplog
  monitor-uri /monitor

frontend k8s-master
  bind 0.0.0.0:16443
  bind 127.0.0.1:16443
  mode tcp
  option tcplog
  tcp-request inspect-delay 5s
  default_backend k8s-master

backend k8s-master
  mode tcp
  option tcplog
  option tcp-check
  balance roundrobin
  default-server inter 10s downinter 5s rise 2 fall 2 slowstart 60s maxconn 250 maxqueue 256 weight 100
  server k8s-master01  192.168.43.183:6443  check
  server k8s-master02  192.168.43.184:6443  check
  server k8s-master03  192.168.43.185:6443  check
EOF
# keepalived配置不一样，注意区分网卡名、IP地址和虚拟IP地址
# 检查服务器网卡名
ip a 或 ifconfig
# k8s-master01 Keepalived配置
mkdir /etc/keepalived
cat << EOF > /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
    router_id LVS_DEVEL
script_user root
    enable_script_security
}
vrrp_script chk_apiserver {
    script "/etc/keepalived/check_apiserver.sh"
    interval 5
    weight -5
    fall 2  
rise 1
}
vrrp_instance VI_1 {
    state MASTER
    interface ens33
    mcast_src_ip 192.168.43.183
    virtual_router_id 51
    priority 101
    advert_int 2
    authentication {
        auth_type PASS
        auth_pass K8SHA_KA_AUTH
    }
    virtual_ipaddress {
        192.168.43.182
    }
    track_script {
       chk_apiserver
    }
}
EOF
# k8s-master02 Keepalived配置
mkdir /etc/keepalived
cat << EOF > /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
    router_id LVS_DEVEL
script_user root
    enable_script_security
}
vrrp_script chk_apiserver {
    script "/etc/keepalived/check_apiserver.sh"
   interval 5
    weight -5
    fall 2  
rise 1
}
vrrp_instance VI_1 {
    state BACKUP
    interface ens33
    mcast_src_ip 192.168.43.184
    virtual_router_id 51
    priority 100
    advert_int 2
    authentication {
        auth_type PASS
        auth_pass K8SHA_KA_AUTH
    }
    virtual_ipaddress {
        192.168.43.182
    }
    track_script {
       chk_apiserver
    }
}
EOF
# k8s-master03 Keepalived配置
mkdir /etc/keepalived
cat << EOF > /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
    router_id LVS_DEVEL
script_user root
    enable_script_security
}
vrrp_script chk_apiserver {
    script "/etc/keepalived/check_apiserver.sh"
 interval 5
    weight -5
    fall 2  
rise 1
}
vrrp_instance VI_1 {
    state BACKUP
    interface ens33
    mcast_src_ip 192.168.43.185
    virtual_router_id 51
    priority 100
    advert_int 2
    authentication {
        auth_type PASS
        auth_pass K8SHA_KA_AUTH
    }
    virtual_ipaddress {
        192.168.43.182
    }
    track_script {
       chk_apiserver
    }
}
EOF
# 所有master节点配置Keepalived健康检查脚本
cat << EOF > /etc/keepalived/check_apiserver.sh 
#!/bin/bash
err=0
for k in $(seq 1 3)
do
    check_code=$(pgrep haproxy)
    if [[ $check_code == "" ]]; then
        err=$(expr $err + 1)
        sleep 1
        continue
    else
        err=0
        break
    fi
done

if [[ $err != "0" ]]; then
    echo "systemctl stop keepalived"
    /usr/bin/systemctl stop keepalived
    exit 1
else
    exit 0
fi
EOF
# 赋予可执行权限
chmod +x /etc/keepalived/check_apiserver.sh
# 启动haproxy和Keepalived并加入开机启动
systemctl start haproxy
systemctl start keepalived
systemctl enable haproxy
systemctl enable keepalived

# 测试一波
telnet k8s-master-vip 16443
ping k8s-master-vip

部署k8s-master(k8s-master01)

在k8s-master01节点上执行，个别步骤在所有master节点执行，已另行说明，没说明的均是在k8s-master01执行。

# 创建初始化文件，注意版本号和IP对应上，
cat << EOF > kubeadm-config.yaml
apiVersion: kubeadm.k8s.io/v1beta2
bootstrapTokens:
- groups:
  - system:bootstrappers:kubeadm:default-node-token
  token: 7t2weq.bjbawausm0jaxury
  ttl: 24h0m0s
  usages:
  - signing
  - authentication
kind: InitConfiguration
localAPIEndpoint:
  advertiseAddress: 192.168.43.183
  bindPort: 6443
nodeRegistration:
  criSocket: /var/run/dockershim.sock
  name: k8s-master01
  taints:
  - effect: NoSchedule
    key: node-role.kubernetes.io/master
---
apiServer:
  certSANs:
  - 192.168.43.182
  timeoutForControlPlane: 4m0s
apiVersion: kubeadm.k8s.io/v1beta2
certificatesDir: /etc/kubernetes/pki
clusterName: kubernetes
controlPlaneEndpoint: 192.168.43.182:16443
controllerManager: {}
dns:
  type: CoreDNS
etcd:
  local:
    dataDir: /var/lib/etcd
imageRepository: registry.cn-hangzhou.aliyuncs.com/google_containers
kind: ClusterConfiguration
kubernetesVersion: v1.23.0
networking:
  dnsDomain: cluster.local
  podSubnet: 172.16.0.0/12
  serviceSubnet: 10.96.0.0/12
scheduler: {}
EOF

# 更新初始化文件
kubeadm config migrate --old-config kubeadm-config.yaml --new-config new.yaml
# 将new.yaml复制到其他master节点上
for i in k8s-master02 k8s-master03;do scp new.yaml $i:/root/;done

# 镜像预下载，节省集群初始化的时间（这一步在所有master节点上执行）
kubeadm config images pull --config /root/new.yaml
# 执行结果如下
[config/images] Pulled registry.cn-hangzhou.aliyuncs.com/google_containers/kube-apiserver:v1.23.0
[config/images] Pulled registry.cn-hangzhou.aliyuncs.com/google_containers/kube-controller-manager:v1.23.0
[config/images] Pulled registry.cn-hangzhou.aliyuncs.com/google_containers/kube-scheduler:v1.23.0
[config/images] Pulled registry.cn-hangzhou.aliyuncs.com/google_containers/kube-proxy:v1.23.0
[config/images] Pulled registry.cn-hangzhou.aliyuncs.com/google_containers/pause:3.6
[config/images] Pulled registry.cn-hangzhou.aliyuncs.com/google_containers/etcd:3.5.1-0
[config/images] Pulled registry.cn-hangzhou.aliyuncs.com/google_containers/coredns:v1.8.6

# master01初始化，初始化完成后，加入其他节点即可
kubeadm init --config /root/new.yaml  --upload-certs
# 初始化如果失败，可用下面命令清除初始化信息，然后再次尝试初始化
kubeadm reset -f ; ipvsadm --clear  ; rm -rf ~/.kube
# 初始化成功类似于下面输出，保存好这些信息
...
Your Kubernetes control-plane has initialized successfully!

To start using your cluster, you need to run the following as a regular user:

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

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

  export KUBECONFIG=/etc/kubernetes/admin.conf

You should now deploy a pod network to the cluster.
Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at:
  https://kubernetes.io/docs/concepts/cluster-administration/addons/

You can now join any number of the control-plane node running the following command on each as root:

  kubeadm join 192.168.43.182:16443 --token 7t2weq.bjbawausm0jaxury \
        --discovery-token-ca-cert-hash sha256:5257d44118ab035adc5af89dd7d5a24ca4c31c33e1918b3453ea9aa32597121b \
        --control-plane --certificate-key 9a2e86718fceba001c96e503e9df47db3a645d4917bf783decaea9c5d0a726ed

Please note that the certificate-key gives access to cluster sensitive data, keep it secret!
As a safeguard, uploaded-certs will be deleted in two hours; If necessary, you can use
"kubeadm init phase upload-certs --upload-certs" to reload certs afterward.

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

kubeadm join 192.168.43.182:16443 --token 7t2weq.bjbawausm0jaxury \
        --discovery-token-ca-cert-hash sha256:5257d44118ab035adc5af89dd7d5a24ca4c31c33e1918b3453ea9aa32597121b

# 按照提示，如果你是普通用户在操作，执行一下下面几条
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
# 如果是root用户在操作初始化，执行下面一条即可
export KUBECONFIG=/etc/kubernetes/admin.conf

# 查看docker镜像,可以看到kube..和etcd等镜像
docker images

# Token过期后生成新的token（没提示过期下面两步就不用管了）
kubeadm token create --print-join-command
# Master需要生成--certificate-key
kubeadm init phase upload-certs  --upload-certs

其他节点加入集群

其他master节点加入k8s-master01

# 根据kubeadm init提示的token
kubeadm join 192.168.43.182:16443 --token 7t2weq.bjbawausm0jaxury \
        --discovery-token-ca-cert-hash sha256:5257d44118ab035adc5af89dd7d5a24ca4c31c33e1918b3453ea9aa32597121b \
        --control-plane --certificate-key 9a2e86718fceba001c96e503e9df47db3a645d4917bf783decaea9c5d0a726ed

node节点加入k8s-master01

# 根据kubeadm init提示的token
kubeadm join 192.168.43.182:16443 --token 7t2weq.bjbawausm0jaxury \
        --discovery-token-ca-cert-hash sha256:5257d44118ab035adc5af89dd7d5a24ca4c31c33e1918b3453ea9aa32597121b
# master01上查看加入后的节点信息，因为还未配置CNI插件，所以node之间通信还未打通
[root@k8s-master01 ~]# kubectl get no
NAME           STATUS     ROLES                  AGE     VERSION
k8s-master01   NotReady   control-plane,master   19m     v1.23.0
k8s-master02   NotReady   control-plane,master   3m39s   v1.23.0
k8s-master03   NotReady   control-plane,master   3m35s   v1.23.0
k8s-node01     NotReady   <none>                 2m21s   v1.23.0
k8s-node02     NotReady   <none>                 2m21s   v1.23.0

配置calico网络

在k8s-master01节点上执行

网络方案也可以选择其他(例如：flannel等)

# 先把所需的配置文件从GitHub拉下来
git clone https://github.com/deemoprobe/k8s-ha-install.git
# 切换到1.23分支并进入calico文件夹
cd /root/k8s-ha-install && git checkout manual-installation-v1.23.x && cd calico/
# 替换一下POD网段
POD_SUBNET=`cat /etc/kubernetes/manifests/kube-controller-manager.yaml | grep cluster-cidr= | awk -F= '{print $NF}'`
sed -i "s#POD_CIDR#${POD_SUBNET}#g" calico.yaml
# 应用calico插件
kubectl apply -f calico.yaml
# 集群节点均已处于Ready状态
[root@k8s-master01 calico]# kubectl get no
NAME           STATUS   ROLES                  AGE   VERSION
k8s-master01   Ready    control-plane,master   29m   v1.23.0
k8s-master02   Ready    control-plane,master   13m   v1.23.0
k8s-master03   Ready    control-plane,master   13m   v1.23.0
k8s-node01     Ready    <none>                 11m   v1.23.0
k8s-node02     Ready    <none>                 11m   v1.23.0
# 查看calico Pod是否都正常
kubectl get pod -A
# 如果不正常，可以排查一下，一般是镜像拉取问题，多等待几分钟即可，也可以根据报错简单处理一下
kubectl describe pod XXX -n kube-system
# 比如我这里有个pod处于pending状态，查看一下原因
[root@k8s-master01 calico]# kubectl get pod -A
NAMESPACE     NAME                                       READY   STATUS    RESTARTS      AGE
...
kube-system   calico-typha-8445487f56-hx8w9              1/1     Running   0             11m
kube-system   calico-typha-8445487f56-mh6tp              0/1     Pending   0             11m
kube-system   calico-typha-8445487f56-pxthb              1/1     Running   0             11m
...
# 可以看到提示说2个node节点无法提供足量的pod端口分配需求，而且提示master节点设置了污点
[root@k8s-master01 calico]# kubectl describe pod calico-typha-8445487f56-mh6tp -n kube-system
...
Events:
  Type     Reason            Age                    From               Message
  ----     ------            ----                   ----               -------
  Warning  FailedScheduling  11m                    default-scheduler  0/5 nodes are available: 2 node(s) had taint {node.kubernetes.io/not-ready: }, that the pod didn't tolerate, 3 node(s) had taint {node-role.kubernetes.io/master: }, that the pod didn't tolerate.
  Warning  FailedScheduling  10m                    default-scheduler  0/5 nodes are available: 1 node(s) didn't have free ports for the requested pod ports, 1 node(s) had taint {node.kubernetes.io/not-ready: }, that the pod didn't tolerate, 3 node(s) had taint {node-role.kubernetes.io/master: }, that the pod didn't tolerate.
  Warning  FailedScheduling  10m                    default-scheduler  0/5 nodes are available: 2 node(s) didn't have free ports for the requested pod ports, 3 node(s) had taint {node-role.kubernetes.io/master: }, that the pod didn't tolerate.
  Warning  FailedScheduling  8m24s (x1 over 9m24s)  default-scheduler  0/5 nodes are available: 2 node(s) didn't have free ports for the requested pod ports, 3 node(s) had taint {node-role.kubernetes.io/master: }, that the pod didn't tolerate.'
# 确认一下，可以看到三个master节点打上了不可调度pod的污点
[root@k8s-master01 calico]# for i in k8s-master01 k8s-master02 k8s-master03;do kubectl describe node $i | grep -i taint;done
Taints:             node-role.kubernetes.io/master:NoSchedule
Taints:             node-role.kubernetes.io/master:NoSchedule
Taints:             node-role.kubernetes.io/master:NoSchedule
# 由于是练习环境，我就把不可调度的污点取消了，如果是生产环境，建议扩容node工作节点来实现足量的端口分配
[root@k8s-master01 calico]# for i in k8s-master01 k8s-master02 k8s-master03;do kubectl taint node $i node-role.kubernetes.io/master:NoSchedule-;done
node/k8s-master01 untainted
node/k8s-master02 untainted
node/k8s-master03 untainted
# 污点成功取消
[root@k8s-master01 calico]# for i in k8s-master01 k8s-master02 k8s-master03;do kubectl describe node $i | grep -i taint;done
Taints:             <none>
Taints:             <none>
Taints:             <none>
# 再查看刚才处于pending的pod发现已经处于running状态了
[root@k8s-master01 calico]# kubectl get po -A | grep calico-typha-8445487f56-mh6tp
kube-system   calico-typha-8445487f56-mh6tp              1/1     Running   0             23m

部署Metrics

在新版的Kubernetes中系统资源的采集均使用Metrics-server，可以通过Metrics采集节点和Pod的内存、磁盘、CPU和网络的使用率。

# 将Master01节点的front-proxy-ca.crt复制到所有Node节点
[root@k8s-master01 calico]# for i in k8s-node01 k8s-node02;do scp /etc/kubernetes/pki/front-proxy-ca.crt $i:/etc/kubernetes/pki/front-proxy-ca.crt;done
front-proxy-ca.crt                                                                                                   100% 1115   593.4KB/s   00:00    
front-proxy-ca.crt                                                                                                   100% 1115     1.4MB/s   00:00  
# 安装metrics server
[root@k8s-master01 calico]# cd /root/k8s-ha-install/kubeadm-metrics-server
[root@k8s-master01 kubeadm-metrics-server]# kubectl apply -f comp.yaml 
serviceaccount/metrics-server created
clusterrole.rbac.authorization.k8s.io/system:aggregated-metrics-reader created
clusterrole.rbac.authorization.k8s.io/system:metrics-server created
rolebinding.rbac.authorization.k8s.io/metrics-server-auth-reader created
clusterrolebinding.rbac.authorization.k8s.io/metrics-server:system:auth-delegator created
clusterrolebinding.rbac.authorization.k8s.io/system:metrics-server created
service/metrics-server created
deployment.apps/metrics-server created
apiservice.apiregistration.k8s.io/v1beta1.metrics.k8s.io created
# 查看运行状态
[root@k8s-master01 kubeadm-metrics-server]# kubectl get po -A | grep metrics
kube-system   metrics-server-5cf8885b66-2nnb6            1/1     Running   0             68s
# 部署后便可以查看指标了
[root@k8s-master01 kubeadm-metrics-server]# kubectl top node
NAME           CPU(cores)   CPU%   MEMORY(bytes)   MEMORY%   
k8s-master01   177m         8%     1196Mi          64%       
k8s-master02   153m         7%     1101Mi          58%       
k8s-master03   163m         8%     1102Mi          58%       
k8s-node01     88m          4%     848Mi           45%       
k8s-node02     85m          4%     842Mi           45%       
[root@k8s-master01 kubeadm-metrics-server]# kubectl top po
NAME                     CPU(cores)   MEMORY(bytes)   
nginx-85b98978db-7mn6r   0m           3Mi

部署Dashboard

Dashboard是一个展示Kubernetes集群资源和Pod日志，甚至可以执行容器命令的web控制台。

# 直接部署即可
[root@k8s-master01 kubeadm-metrics-server]# cd /root/k8s-ha-install/dashboard/
[root@k8s-master01 dashboard]# ls
dashboard-user.yaml  dashboard.yaml
[root@k8s-master01 dashboard]# kubectl apply -f .
serviceaccount/admin-user created
clusterrolebinding.rbac.authorization.k8s.io/admin-user created
namespace/kubernetes-dashboard created
serviceaccount/kubernetes-dashboard created
service/kubernetes-dashboard created
secret/kubernetes-dashboard-certs created
secret/kubernetes-dashboard-csrf created
secret/kubernetes-dashboard-key-holder created
configmap/kubernetes-dashboard-settings created
role.rbac.authorization.k8s.io/kubernetes-dashboard created
clusterrole.rbac.authorization.k8s.io/kubernetes-dashboard created
rolebinding.rbac.authorization.k8s.io/kubernetes-dashboard created
clusterrolebinding.rbac.authorization.k8s.io/kubernetes-dashboard created
deployment.apps/kubernetes-dashboard created
service/dashboard-metrics-scraper created
deployment.apps/dashboard-metrics-scraper created
# 查看dashboard端口，默认是NodePort模式，访问集群内任意节点的31073端口即可
[root@k8s-master01 dashboard]# kubectl get svc -owide -A | grep dash
kubernetes-dashboard   dashboard-metrics-scraper   ClusterIP   10.105.172.8    <none>        8000/TCP                 19m    k8s-app=dashboard-metrics-scraper
kubernetes-dashboard   kubernetes-dashboard        NodePort    10.99.148.159   <none>        443:31073/TCP            19m    k8s-app=kubernetes-dashboard

访问dashboard：https://集群内任意节点IP:31073

发现提示隐私设置错误的问题，如图：

20211213153948

在Chrome浏览器启动参数加入--test-type --ignore-certificate-errors，然后再访问就没有这个安全提示了

20211213154024

20211213154133

# 获取登陆令牌（token）
[root@k8s-master01 dashboard]# kubectl -n kube-system describe secret $(kubectl -n kube-system get secret | grep admin-user | awk '{print $1}')
Name:         admin-user-token-mwnfs
Namespace:    kube-system
Labels:       <none>
Annotations:  kubernetes.io/service-account.name: admin-user
              kubernetes.io/service-account.uid: 29584392-1cbd-4d5c-91af-9dd4703008aa

Type:  kubernetes.io/service-account-token

Data
====
ca.crt:     1099 bytes
namespace:  11 bytes
token:      eyJhbGciOiJSUzI1NiIsImtpZCI6IjRyZlh6Ukxta0FlajlHREF5ei1mdl8tZmR6ekwteV9fVEIwalQtejRwUk0ifQ.eyJpc3MiOiJrdWJlcm5ldGVzL3NlcnZpY2VhY2NvdW50Iiwia3ViZXJuZXRlcy5pby9zZXJ2aWNlYWNjb3VudC9uYW1lc3BhY2UiOiJrdWJlLXN5c3RlbSIsImt1YmVybmV0ZXMuaW8vc2VydmljZWFjY291bnQvc2VjcmV0Lm5hbWUiOiJhZG1pbi11c2VyLXRva2VuLW13bmZzIiwia3ViZXJuZXRlcy5pby9zZXJ2aWNlYWNjb3VudC9zZXJ2aWNlLWFjY291bnQubmFtZSI6ImFkbWluLXVzZXIiLCJrdWJlcm5ldGVzLmlvL3NlcnZpY2VhY2NvdW50L3NlcnZpY2UtYWNjb3VudC51aWQiOiIyOTU4NDM5Mi0xY2JkLTRkNWMtOTFhZi05ZGQ0NzAzMDA4YWEiLCJzdWIiOiJzeXN0ZW06c2VydmljZWFjY291bnQ6a3ViZS1zeXN0ZW06YWRtaW4tdXNlciJ9.pMBMkLAP2AoymIXJC7H47IPu3avdBWPYSZfvjRME7lEQAnbe-SM-yrTFGPzcsJQC3O9gPDvXgIZ1x1tQUtQhc_333GtDMj_VL9oEZxYiOdd578CnBiFmF0BWVX06pAzONgKbguamMD8XEPAvKt4mnlDUr7WCeQJZf_juXKdl7ZOBtrM5Zae0UQHFG6juKLmFP-XxIgoDVIPhcxeAH1ktOHM9Fk1M831hywL1SL2OLHiN52wGLT4WuYrP2iUbJkNpt2PYitSp3iNuh7rESL4Ur7lmFQkLZa9e5vNMCc1wTwOAWvaW4P5TbxtfI_ng4NK_avquiXJY-67D77G-8WKzWg

20211213154451

一些必要的更改

# 更改kube-proxy模式为ipvs
[root@k8s-master01 dashboard]# kubectl edit cm kube-proxy -n kube-system
mode: "ipvs"
# 更新kube-proxy的pod
[root@k8s-master01 dashboard]# kubectl patch daemonset kube-proxy -p "{\"spec\":{\"template\":{\"metadata\":{\"annotations\":{\"date\":\"`date +'%s'`\"}}}}}" -n kube-system
daemonset.apps/kube-proxy patched
# 验证
[root@k8s-master01 dashboard]# curl 127.0.0.1:10249/proxyMode
ipvs

测试集群

# 增加node节点的节点role名称
kubectl label nodes k8s-node1 node-role.kubernetes.io/node=
# 删除node节点的节点role名称
kubectl label nodes k8s-node1 node-role.kubernetes.io/node-

# 添加标签后查看集群状态
[root@k8s-master01 calico]# kubectl get no
NAME           STATUS   ROLES                  AGE   VERSION
k8s-master01   Ready    control-plane,master   56m   v1.23.0
k8s-master02   Ready    control-plane,master   40m   v1.23.0
k8s-master03   Ready    control-plane,master   39m   v1.23.0
k8s-node01     Ready    node                   38m   v1.23.0
k8s-node02     Ready    node                   38m   v1.23.0

# 测试namespace
kubectl get namespace
kubectl create namespace test
kubectl get namespace
kubectl delete namespace test

# 创建nginx实例并开放端口
kubectl create deployment nginx --image=nginx
kubectl expose deployment nginx --port=80 --type=NodePort
# 查看调度状态和端口号
[root@k8s-master01 calico]# kubectl get pod,svc -owide
NAME                         READY   STATUS    RESTARTS   AGE     IP              NODE         NOMINATED NODE   READINESS GATES
pod/nginx-85b98978db-7mn6r   1/1     Running   0          2m16s   172.27.14.193   k8s-node02   <none>           <none>

NAME                 TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)        AGE    SELECTOR
service/kubernetes   ClusterIP   10.96.0.1      <none>        443/TCP        59m    <none>
service/nginx        NodePort    10.104.33.99   <none>        80:31720/TCP   2m6s   app=nginx

可见调度到了k8s-node02（node IP地址是192.168.43.184）上，对应的NodePort为31720

在浏览器输入http://192.168.43.184:31720/ 访问nginx，访问结果如图

20211213143124

至此，基于kubeadm的Kubernetes高可用集群搭建成功。