本文主要是介绍Kubeadm构建高可用k8s集群 v1.21.2，对大家解决编程问题具有一定的参考价值，需要的程序猿们随着小编来一起学习吧！

文章目录

• Kubeadm构建高可用k8s集群 v1.21.2
• • 环境规划
  • • 基础配置
    • 内核升级及优化
    • 基本组件安装
    • 高可用组件安装
    • k8s集群初始化
    • 加入其他Master
    • Node节点配置
    • Calico安装
    • Metrics安装
    • Dashboard安装
    • 访问dashboard
    • 其他配置更改
    • 其他说明

Kubeadm构建高可用k8s集群 v1.21.2

环境规划

基础配置

所有节点配置hosts，修改/etc/hosts如下：
[root@k8s-master01 ~]# cat /etc/hosts
10.4.7.107 k8s-master01
10.4.7.108 k8s-master02
10.4.7.109 k8s-master03
10.4.7.103 k8s-master-lb # 如果不是高可用集群，该IP为Master01的IP
10.4.7.203 k8s-node01
10.4.7.204 k8s-node02

CentOS 7安装yum源如下：
curl -o /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-7.repo
yum install -y yum-utils device-mapper-persistent-data lvm2
yum-config-manager --add-repo https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
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
sed -i -e '/mirrors.cloud.aliyuncs.com/d' -e '/mirrors.aliyuncs.com/d' /etc/yum.repos.d/CentOS-Base.repo

必备工具安装
yum install wget jq psmisc vim net-tools telnet yum-utils device-mapper-persistent-data lvm2 git -y

所有节点关闭防火墙、selinux、dnsmasq、swap。服务器配置如下：
systemctl disable --now firewalld 
systemctl disable --now dnsmasq
systemctl disable --now NetworkManager

setenforce 0
sed -i 's#SELINUX=enforcing#SELINUX=disabled#g' /etc/sysconfig/selinux

关闭swap分区
swapoff -a && sysctl -w vm.swappiness=0
sed -ri '/^[^#]*swap/s@^@#@' /etc/fstab

安装ntpdate
rpm -ivh http://mirrors.wlnmp.com/centos/wlnmp-release-centos.noarch.rpm
yum install ntpdate -y

所有节点同步时间。时间同步配置如下：
ln -sf /usr/share/zoneinfo/Asia/Shanghai /etc/localtime
echo 'Asia/Shanghai' >/etc/timezone
ntpdate time2.aliyun.com
# 加入到crontab
*/5 * * * * /usr/sbin/ntpdate time2.aliyun.com

所有节点配置limit：
ulimit -SHn 65535

vim /etc/security/limits.conf
# 末尾添加如下内容
* soft nofile 655360
* hard nofile 131072
* soft nproc 655350
* hard nproc 655350
* soft memlock unlimited
* hard memlock unlimited

Master01节点免密钥登录其他节点，安装过程中生成配置文件和证书均在Master01上操作，集群管理也在Master01上操作，
阿里云或者AWS上需要单独一台kubectl服务器。密钥配置如下：
ssh-keygen -t rsa
for i in k8s-master01 k8s-master02 k8s-master03 k8s-node01 k8s-node02;do ssh-copy-id -i .ssh/id_rsa.pub $i;done

下载安装所有的源码文件：
git clone https://github.com/dotbalo/k8s-ha-install.git

内核升级及优化

[root@k8s7-200.host.com ~]# cat /etc/redhat-release 
CentOS Linux release 7.6.1810 (Core) 
[root@k8s7-200.host.com ~]# uname -r
3.10.0-957.el7.x86_64

 ~]# wget -O /etc/yum.repos.d/epel.repo https://mirrors.tencent.com/repo/epel-7.repo
 ~]# wget -O /etc/yum.repos.d/CentOS-Base.repo https://mirrors.tencent.com/repo/centos7_base.repo

~]# yum -y install yum-plugin-fastestmirror
~]# yum update -y

~]# rpm -Uvh https://www.elrepo.org/elrepo-release-7.0-3.el7.elrepo.noarch.rpm
~]# rpm -import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org

查看可用内核版本
~]# yum --disablerepo="*" --enablerepo="elrepo-kernel" list available

安装最新版本内核 5.13.0-1.el7.elrepo
~]# yum -y --enablerepo=elrepo-kernel install kernel-ml.x86_64 kernel-ml-devel.x86_64

查看启动器
~]# awk -F\' '$1=="menuentry " {print i++ " : " $2}' /etc/grub2.cfg
0 : CentOS Linux (5.13.0-1.el7.elrepo.x86_64) 7 (Core)
1 : CentOS Linux (3.10.0-1160.31.1.el7.x86_64) 7 (Core)
2 : CentOS Linux (3.10.0-957.el7.x86_64) 7 (Core)
3 : CentOS Linux (0-rescue-7d3920cb5d75497a8862dd8e8e5e1c85) 7 (Core)

设置默认启动内核---0后边内核为我们设置的内核
~]# grub2-set-default 0


查看内核版本默认启动顺序---确保第一个是我们设置的内核
~]# awk -F\' '$1=="menuentry " {print $2}' /etc/grub2.cfg
CentOS Linux (5.13.0-1.el7.elrepo.x86_64) 7 (Core)
CentOS Linux (3.10.0-1160.31.1.el7.x86_64) 7 (Core)
CentOS Linux (3.10.0-957.el7.x86_64) 7 (Core)
CentOS Linux (0-rescue-7d3920cb5d75497a8862dd8e8e5e1c85) 7 (Core)

在各节点执行---重启系统
 ~]# reboot

重启后查看内核：uname -r  是否为我们设置的内核
~]# uname -r
5.13.0-1.el7.elrepo.x86_64	#升级成功！！！

所有节点安装ipvsadm：
yum install ipvsadm ipset sysstat conntrack libseccomp -y

所有节点配置ipvs模块，在内核4.19+版本nf_conntrack_ipv4已经改为nf_conntrack， 4.18以下使用nf_conntrack_ipv4即可：
modprobe -- ip_vs
modprobe -- ip_vs_rr
modprobe -- ip_vs_wrr
modprobe -- ip_vs_sh
modprobe -- nf_conntrack
vim /etc/modules-load.d/ipvs.conf 
	# 加入以下内容
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
然后执行systemctl enable --now systemd-modules-load.service即可

开启一些k8s集群中必须的内核参数，所有节点配置k8s内核：
cat <<EOF > /etc/sysctl.d/k8s.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
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
sysctl --system

#所有节点配置完内核后，重启服务器，保证重启后内核依旧加载
reboot
lsmod | grep --color=auto -e ip_vs -e nf_conntrack

基本组件安装

本次主要安装的是集群中用到的各种组件，比如Docker-ce、Kubernetes各组件等。
所有节点安装Docker-ce

yum install docker-ce -y
mkdir /etc/docker /data/docker
[root@k8s-master01 ~]# cat /etc/docker/daemon.json 
{
  "graph": "/data/docker",
  "storage-driver": "overlay2",
  "insecure-registries": ["registry.access.redhat.com","quay.io","harbor.od.com"],
  "registry-mirrors": ["https://registry.docker-cn.com"],
  "bip": "172.7.107.1/24",
  "exec-opts": ["native.cgroupdriver=systemd"],
  "live-restore": true
}

所有节点设置开机自启动Docker：
systemctl daemon-reload && systemctl enable --now docker

安装k8s组件：
yum list kubeadm.x86_64 --showduplicates | sort -r

所有节点安装最新版本kubeadm：
yum install kubeadm -y

默认配置的pause镜像使用gcr.io仓库，国内可能无法访问，所以这里配置Kubelet使用阿里云的pause镜像：
cat >/etc/sysconfig/kubelet<<EOF
KUBELET_EXTRA_ARGS="--cgroup-driver=systemd --pod-infra-container-image=registry.cn-hangzhou.aliyuncs.com/google_containers/pause-amd64:3.2"
EOF

设置Kubelet开机自启动：
systemctl daemon-reload
systemctl enable --now kubelet

高可用组件安装

（注意：如果不是高可用集群，haproxy和keepalived无需安装）
公有云要用公有云自带的负载均衡，比如阿里云的SLB，腾讯云的ELB，用来替代haproxy和keepalived，因为公有云大部分都是不支持keepalived的，另外如果用阿里云的话，kubectl控制端不能放在master节点，推荐使用腾讯云，因为阿里云的slb有回环的问题，也就是slb代理的服务器不能反向访问SLB，但是腾讯云修复了这个问题。

所有Master节点通过yum安装HAProxy和KeepAlived：
yum install keepalived haproxy -y
所有Master节点配置HAProxy（详细配置参考HAProxy文档，所有Master节点的HAProxy配置相同）：
[root@k8s-master01 etc]# mkdir /etc/haproxy
[root@k8s-master01 etc]# vim /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	10.4.7.107:6443  check
  server k8s-master02	10.4.7.108:6443  check
  server k8s-master03	10.4.7.109:6443  check
  
所有Master节点配置KeepAlived，配置不一样，注意区分 
[root@k8s-master01 pki]# vim /etc/keepalived/keepalived.conf #注意每个节点的IP和网卡（interface参数）
Master01节点的配置：
[root@k8s-master01 etc]# mkdir /etc/keepalived

[root@k8s-master01 ~]# vim /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 eth0
    mcast_src_ip 10.4.7.107
    virtual_router_id 51
    priority 101
    advert_int 2
    authentication {
        auth_type PASS
        auth_pass K8SHA_KA_AUTH
    }
    virtual_ipaddress {
        10.4.7.103
    }
    track_script {
       chk_apiserver
    }
}

Master02节点的配置：
! 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 eth0
    mcast_src_ip 10.4.7.108
    virtual_router_id 51
    priority 100
    advert_int 2
    authentication {
        auth_type PASS
        auth_pass K8SHA_KA_AUTH
    }
    virtual_ipaddress {
        10.4.7.103
    }
    track_script {
       chk_apiserver
    }
}

Master03节点的配置：
! 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 eth0
    mcast_src_ip 10.4.7.109
    virtual_router_id 51
    priority 100
    advert_int 2
    authentication {
        auth_type PASS
        auth_pass K8SHA_KA_AUTH
    }
    virtual_ipaddress {
        10.4.7.103
    }
    track_script {
       chk_apiserver
    }
}

所有master节点配置KeepAlived健康检查文件：
[root@k8s-master01 keepalived]# cat /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

加x权限
chmod +x /etc/keepalived/check_apiserver.sh

启动haproxy和keepalived
[root@k8s-master01 keepalived]# systemctl daemon-reload
[root@k8s-master01 keepalived]# systemctl enable --now haproxy
[root@k8s-master01 keepalived]# systemctl enable --now keepalived

重要：如果安装了keepalived和haproxy，需要测试keepalived是否是正常的
测试VIP
[root@k8s-master01 ~]# ping 10.4.7.103 -c 4
PING 10.4.7.103 (10.4.7.103) 56(84) bytes of data.
64 bytes from 10.4.7.103: icmp_seq=1 ttl=64 time=0.464 ms
64 bytes from 10.4.7.103: icmp_seq=2 ttl=64 time=0.063 ms
64 bytes from 10.4.7.103: icmp_seq=3 ttl=64 time=0.062 ms
64 bytes from 10.4.7.103: icmp_seq=4 ttl=64 time=0.063 ms

--- 10.4.7.103 ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3106ms
rtt min/avg/max/mdev = 0.062/0.163/0.464/0.173 ms
[root@k8s-master01 ~]# telnet 10.4.7.103 16443
Trying 10.4.7.103...
Connected to 10.4.7.103.
Escape character is '^]'.
Connection closed by foreign host.

如果ping不通且telnet没有出现 ] ，则认为VIP不可以，不可在继续往下执行，需要排查keepalived的问题，比如防火墙和selinux，haproxy和keepalived的状态，监听端口等
所有节点查看防火墙状态必须为disable和inactive：systemctl status firewalld
所有节点查看selinux状态，必须为disable：getenforce
master节点查看haproxy和keepalived状态：systemctl status keepalived haproxy
master节点查看监听端口：netstat -lntp

k8s集群初始化

官方初始化文档：
https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/high-availability/

Master01节点创建kubeadm-config.yaml配置文件如下：
Master01：（# 注意，如果不是高可用集群，10.4.7.103:16443改为master01的地址，16443改为apiserver的端口，默认是6443，注意更改v1.18.5自己服务器kubeadm的版本：kubeadm version）

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: 10.4.7.107
  bindPort: 6443
nodeRegistration:
  criSocket: /var/run/dockershim.sock
  name: k8s-master01
  taints:
  - effect: NoSchedule
    key: node-role.kubernetes.io/master
---
apiServer:
  certSANs:
  - 10.4.7.103
  timeoutForControlPlane: 4m0s
apiVersion: kubeadm.k8s.io/v1beta2
certificatesDir: /etc/kubernetes/pki
clusterName: kubernetes
controlPlaneEndpoint: 10.4.7.103:16443
controllerManager: {}
dns:
  type: CoreDNS
etcd:
  local:
    dataDir: /var/lib/etcd
imageRepository: registry.cn-hangzhou.aliyuncs.com/google_containers
kind: ClusterConfiguration
kubernetesVersion: v1.20.0
networking:
  dnsDomain: cluster.local
  podSubnet: 172.168.0.0/12
  serviceSubnet: 10.96.0.0/12
scheduler: {}

更新kubeadm文件
kubeadm config migrate --old-config kubeadm-config.yaml --new-config new.yaml
将new.yaml文件复制到其他master节点，之后所有Master节点提前下载镜像，可以节省初始化时间：
kubeadm config images pull --config /root/new.yaml 

所有节点设置开机自启动kubelet
systemctl enable --now kubelet（如果启动失败无需管理，初始化成功以后即可启动）

Master01节点初始化，初始化以后会在/etc/kubernetes目录下生成对应的证书和配置文件，之后其他Master节点加入Master01即可：
kubeadm init --config /root/new.yaml  --upload-certs

如果初始化失败，重置后再次初始化，命令如下：
kubeadm reset -f ; ipvsadm --clear  ; rm -rf ~/.kube
初始化成功以后，会产生Token值，用于其他节点加入时使用，因此要记录下初始化成功生成的token值（令牌值）：
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 10.4.7.103:16443 --token 7t2weq.bjbawausm0jaxury \
    --discovery-token-ca-cert-hash sha256:8c92ecb336be2b9372851a9af2c7ca1f7f60c12c68f6ffe1eb513791a1b8a908 \
    --control-plane --certificate-key ac2854de93aaabdf6dc440322d4846fc230b290c818c32d6ea2e500fc930b0aa

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 10.4.7.103:16443 --token 7t2weq.bjbawausm0jaxury \
    --discovery-token-ca-cert-hash sha256:8c92ecb336be2b9372851a9af2c7ca1f7f60c12c68f6ffe1eb513791a1b8a908

--------------------------------------------------------------------------------------------------

Master01节点配置环境变量，用于访问Kubernetes集群：
cat <<EOF >> /root/.bashrc
export KUBECONFIG=/etc/kubernetes/admin.conf
EOF

source /root/.bashrc

查看节点状态：
 [root@k8s-master01 ~]# kubectl get nodes
NAME           STATUS     ROLES                  AGE   VERSION
k8s-master01   NotReady   control-plane,master   74s   v1.21.2

采用初始化安装方式，所有的系统组件均以容器的方式运行并且在kube-system命名空间内，此时可以查看Pod状态：
[root@k8s-master01 ~]# kubectl get pods -n kube-system -o wide
NAME                                   READY     STATUS    RESTARTS   AGE       IP              NODE
coredns-777d78ff6f-kstsz               0/1       Pending   0          14m       <none>          <none>
coredns-777d78ff6f-rlfr5               0/1       Pending   0          14m       <none>          <none>
etcd-k8s-master01                      1/1       Running   0          14m       10.4.7.107   k8s-master01
kube-apiserver-k8s-master01            1/1       Running   0          13m       10.4.7.107   k8s-master01
kube-controller-manager-k8s-master01   1/1       Running   0          13m       10.4.7.107   k8s-master01
kube-proxy-8d4qc                       1/1       Running   0          14m       10.4.7.107   k8s-master01
kube-scheduler-k8s-master01            1/1       Running   0          13m       10.4.7.107   k8s-master01

加入其他Master

Token过期后生成新的token：
kubeadm token create --print-join-command

Master需要生成--certificate-key
kubeadm init phase upload-certs  --upload-certs


初始化其他master加入集群
~]# kubeadm join 10.4.7.103:16443 --token urfd57.3kpp2gcj7iivloxu --discovery-token-ca-cert-hash sha256:5b69c764326bb878267d82840bc4908da2db5a887e6cd66865e3d8330b448258  \ --control-plane --certificate-key 3f62c7a3cc3d36611dc18913b000a94b09d82d4025017f85d7df094d38fbe670

Node节点配置

Node节点上主要部署公司的一些业务应用，生产环境中不建议Master节点部署系统组件之外的其他Pod，测试环境可以允许Master节点部署Pod以节省系统资源。

kubeadm join 10.4.7.103:16443 --token 7t2weq.bjbawausm0jaxury \
    --discovery-token-ca-cert-hash sha256:8c92ecb336be2b9372851a9af2c7ca1f7f60c12c68f6ffe1eb513791a1b8a908

所有节点初始化完成后，查看集群状态
[root@k8s-master01 ~]# kubectl get nodes -o wide
NAME           STATUS     ROLES                  AGE   VERSION   INTERNAL-IP   EXTERNAL-IP   OS-IMAGE                KERNEL-VERSION               CONTAINER-RUNTIME
k8s-master01   Ready      control-plane,master   24h   v1.21.2   10.4.7.107    <none>        CentOS Linux 7 (Core)   5.13.1-1.el7.elrepo.x86_64   docker://20.10.7
k8s-master02   Ready      control-plane,master   24h   v1.21.2   10.4.7.108    <none>        CentOS Linux 7 (Core)   5.13.1-1.el7.elrepo.x86_64   docker://20.10.7
k8s-master03   Ready      control-plane,master   24h   v1.21.2   10.4.7.109    <none>        CentOS Linux 7 (Core)   5.13.1-1.el7.elrepo.x86_64   docker://20.10.7
k8s-node01     Ready      <none>                 24h   v1.21.2   10.4.7.203    <none>        CentOS Linux 7 (Core)   5.13.1-1.el7.elrepo.x86_64   docker://20.10.7
k8s-node02     NotReady   <none>                 24h   v1.21.2   10.4.7.204    <none>        CentOS Linux 7 (Core)   5.13.1-1.el7.elrepo.x86_64   docker://20.10.7

Calico安装

以下步骤只在master01执行

cd /root/k8s-ha-install && git checkout manual-installation-v1.20.x && cd calico/
修改calico-etcd.yaml的以下位置
sed -i 's#etcd_endpoints: "http://<ETCD_IP>:<ETCD_PORT>"#etcd_endpoints: "https://10.4.7.107:2379,https://10.4.7.108:2379,https://10.4.7.109:2379"#g' calico-etcd.yaml


ETCD_CA=`cat /etc/kubernetes/pki/etcd/ca.crt | base64 | tr -d '\n'`
ETCD_CERT=`cat /etc/kubernetes/pki/etcd/server.crt | base64 | tr -d '\n'`
ETCD_KEY=`cat /etc/kubernetes/pki/etcd/server.key | base64 | tr -d '\n'`
sed -i "s@# etcd-key: null@etcd-key: ${ETCD_KEY}@g; s@# etcd-cert: null@etcd-cert: ${ETCD_CERT}@g; s@# etcd-ca: null@etcd-ca: ${ETCD_CA}@g" calico-etcd.yaml


sed -i 's#etcd_ca: ""#etcd_ca: "/calico-secrets/etcd-ca"#g; s#etcd_cert: ""#etcd_cert: "/calico-secrets/etcd-cert"#g; s#etcd_key: "" #etcd_key: "/calico-secrets/etcd-key" #g' calico-etcd.yaml

POD_SUBNET=`cat /etc/kubernetes/manifests/kube-controller-manager.yaml | grep cluster-cidr= | awk -F= '{print $NF}'`



# 注意下面的这个步骤是把calico-etcd.yaml文件里面的CALICO_IPV4POOL_CIDR下的网段改成自己的Pod网段，也就是把192.168.x.x/16改成自己的集群网段，并打开注释：
所以更改的时候请确保这个步骤的这个网段没有被统一替换掉，如果被替换掉了，还请改回来：
sed -i 's@# - name: CALICO_IPV4POOL_CIDR@- name: CALICO_IPV4POOL_CIDR@g; s@#   value: "192.168.0.0/16"@  value: '"${POD_SUBNET}"'@g' calico-etcd.yaml

kubectl apply -f calico-etcd.yaml

查看容器状态
[root@k8s-master01 calico]# kubectl  get po -n kube-system
NAME                                       READY   STATUS    RESTARTS   AGE
calico-kube-controllers-5f6d4b864b-pwvnb   1/1     Running   0          3m29s
calico-node-5lz9m                          1/1     Running   0          3m29s
calico-node-8z4bg                          1/1     Running   0          3m29s
calico-node-lmzvf                          1/1     Running   0          3m29s
calico-node-mpngv                          1/1     Running   0          3m29s
calico-node-vmqsl                          1/1     Running   0          3m29s
coredns-54d67798b7-8525g                   1/1     Running   0          39m
coredns-54d67798b7-fxs72                   1/1     Running   0          39m
etcd-k8s-master01                          1/1     Running   0          39m
etcd-k8s-master02                          1/1     Running   0          33m
etcd-k8s-master03                          1/1     Running   0          31m
kube-apiserver-k8s-master01                1/1     Running   0          39m
kube-apiserver-k8s-master02                1/1     Running   0          33m
kube-apiserver-k8s-master03                1/1     Running   0          30m
kube-controller-manager-k8s-master01       1/1     Running   1          39m
kube-controller-manager-k8s-master02       1/1     Running   0          33m
kube-controller-manager-k8s-master03       1/1     Running   0          31m
kube-proxy-hnkmj                           1/1     Running   0          39m
kube-proxy-jk4dm                           1/1     Running   0          32m
kube-proxy-nbcg2                           1/1     Running   0          32m
kube-proxy-qv9k7                           1/1     Running   0          32m
kube-proxy-x6xdc                           1/1     Running   0          33m
kube-scheduler-k8s-master01                1/1     Running   1          39m
kube-scheduler-k8s-master02                1/1     Running   0          33m
kube-scheduler-k8s-master03                1/1     Running   0          30m

Metrics安装

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
scp /etc/kubernetes/pki/front-proxy-ca.crt k8s-node01:/etc/kubernetes/pki/front-proxy-ca.crt
scp /etc/kubernetes/pki/front-proxy-ca.crt k8s-node(其他节点自行拷贝):/etc/kubernetes/pki/front-proxy-ca.crt

安装metrics server
cd /root/k8s-ha-install/metrics-server-0.4.x-kubeadm/

[root@k8s-master01 metrics-server-0.4.x-kubeadm]# kubectl  create -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


查看状态
[root@k8s-master01 metrics-server-0.4.x-kubeadm]# kubectl  top node
NAME           CPU(cores)   CPU%   MEMORY(bytes)   MEMORY%   
k8s-master01   109m         2%     1296Mi          33%       
k8s-master02   99m          2%     1124Mi          29%       
k8s-master03   104m         2%     1082Mi          28%       
k8s-node01     55m          1%     761Mi           19%       
k8s-node02     53m          1%     663Mi           17%

Dashboard安装

Dashboard用于展示集群中的各类资源，同时也可以通过Dashboard实时查看Pod的日志和在容器中执行一些命令等。
安装最新版查阅官方GitHub地址：https://github.com/kubernetes/dashboard

安装指定版本dashboard
cd /root/k8s-ha-install/dashboard/

[root@k8s-master01 dashboard]# kubectl  create -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


创建管理员用户vim admin.yaml
apiVersion: v1
kind: ServiceAccount
metadata:
  name: admin-user
  namespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding 
metadata: 
  name: admin-user
  annotations:
    rbac.authorization.kubernetes.io/autoupdate: "true"
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: cluster-admin
subjects:
- kind: ServiceAccount
  name: admin-user
  namespace: kube-system
  
kubectl apply -f admin.yaml -n kube-system

访问dashboard

更改dashboard的svc为NodePort：
kubectl edit svc kubernetes-dashboard -n kubernetes-dashboard

将ClusterIP更改为NodePort（如果已经为NodePort忽略此步骤）：
查看端口号：
[root@k8s-master01 ~]# kubectl get svc kubernetes-dashboard -n kubernetes-dashboard
NAME                   TYPE       CLUSTER-IP        EXTERNAL-IP   PORT(S)         AGE
kubernetes-dashboard   NodePort   192.174.125.243   <none>        443:31228/TCP   24h

根据自己的实例端口号，通过任意安装了kube-proxy的宿主机或者VIP的IP+端口即可访问到dashboard：
访问Dashboard：https://10.4.7.103:31228，选择登录方式为令牌（即token方式）

查看token值：
~]# kubectl -n kube-system describe secret $(kubectl -n kube-system get secret | grep admin-user | awk '{print $1}')

其他配置更改

将Kube-proxy改为ipvs模式，因为在初始化集群的时候注释了ipvs配置，所以需要自行修改一下：
在master01节点执行
kubectl edit cm kube-proxy -n kube-system
mode: “ipvs”
更新Kube-Proxy的Pod：
kubectl patch daemonset kube-proxy -p "{\"spec\":{\"template\":{\"metadata\":{\"annotations\":{\"date\":\"`date +'%s'`\"}}}}}" -n kube-system
验证Kube-Proxy模式
[root@k8s-master01 1.1.1]# curl 127.0.0.1:10249/proxyMode
ipvs

其他说明

注意：kubeadm安装的集群，证书有效期默认是一年。master节点的kube-apiserver、kube-scheduler、kube-controller-manager、etcd都是以容器运行的。可以通过kubectl get po -n kube-system查看。
启动和二进制不同的是，
kubelet的配置文件在/etc/sysconfig/kubelet和/var/lib/kubelet/config.yaml
其他组件的配置文件在/etc/Kubernetes/manifests目录下，比如kube-apiserver.yaml，该yaml文件更改后，kubelet会自动刷新配置，也就是会重启pod。不能再次创建该文件
Kubeadm安装后，master节点默认不允许部署pod，可以通过以下方式打开：

查看Taints：
[root@k8s-master01 ~]# kubectl  describe node -l node-role.kubernetes.io/master=  | grep Taints
Taints:             node-role.kubernetes.io/master:NoSchedule
Taints:             node-role.kubernetes.io/master:NoSchedule
Taints:             node-role.kubernetes.io/master:NoSchedule
删除Taint：
[root@k8s-master01 ~]# kubectl  taint node  -l node-role.kubernetes.io/master node-role.kubernetes.io/master:NoSchedule-
node/k8s-master01 untainted
node/k8s-master02 untainted
node/k8s-master03 untainted
[root@k8s-master01 ~]# kubectl  describe node -l node-role.kubernetes.io/master=  | grep Taints
Taints:             <none>
Taints:             <none>
Taints:             <none>

这篇关于Kubeadm构建高可用k8s集群 v1.21.2的文章就介绍到这儿，希望我们推荐的文章对大家有所帮助，也希望大家多多支持为之网！