一、所有机器

1.优化机器

1.关闭selinux
#永久
[root@k8s-master01 ~]# sed -i 's#enforcing#disabled#g' /etc/selinux/config
#临时
[root@k8s-master01 ~]# setenforce 0
#检查
[root@k8s-master01 ~]# /usr/sbin/sestatus -v  
SELinux status:                 enabled

2.关闭防火墙
[root@k8s-master01 ~]# systemctl disable --now firewalld

3.关闭swap分区
[root@k8s-master01 ~]# swapoff -a
[root@k8s-master01 ~]# sed -i 's/^.*centos-swap/# &/g' /etc/fstab
[root@k8s-master01 ~]# echo 'KUBELET_EXTRA_ARGS=\"--fail-swap-on=false\"' > /etc/sysconfig/kubelet

4.优化系统
[root@k8s-master01 ~]# rm -f /etc/yum.repos.d/*
[root@k8s-master01 ~]# curl -o /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-7.repo
[root@k8s-master01 ~]# curl -o /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo

[root@k8s-master01 ~]# yum makecache
[root@k8s-master01 ~]# yum update -y --exclud=kernel*

5.配置hosts文件
[root@k8s-master01 ~]# vim /etc/hosts
10.0.0.81 k8s-master01 
10.0.0.84 k8s-node01

2.更新内核版本

#下载
[root@k8s-master01 ~]# wget https://elrepo.org/linux/kernel/el7/x86_64/RPMS/kernel-lt-5.4.155-1.el7.elrepo.x86_64.rpm
[root@k8s-master01 ~]# wget https://elrepo.org/linux/kernel/el7/x86_64/RPMS/kernel-lt-devel-5.4.155-1.el7.elrepo.x86_64.rpm

#安装
[root@k8s-master01 ~]# yum localinstall -y kernel*

#设置启动优先级
[root@k8s-master01 ~]# grub2-set-default  0 && grub2-mkconfig -o /etc/grub2.cfg

#查看内核版本
[root@k8s-master01 ~]# grubby --default-kernel
/boot/vmlinuz-5.4.155-1.el7.elrepo.x86_64

3.安装ipvs

1.安装依赖
[root@k8s-master01 ~]# yum install conntrack-tools ipvsadm ipset libseccomp wget expect vim net-tools ntp bash-completion ipvsadm jq iptables conntrack sysstat yum-utils device-mapper-persistent-data lvm2 ntp ntpdate -y

2.加载ipvs模块
[root@k8s-master01 ~]# cat > /etc/sysconfig/modules/ipvs.modules <<  EOF
#!/bin/bash
ipvs_modules="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 nf_conntrack"
for kernel_module in \${ipvs_modules}; do
  /sbin/modinfo -F filename \${kernel_module} > /dev/null 2>&1
  if [ $? -eq 0 ]; then
    /sbin/modprobe \${kernel_module}
  fi
done
EOF

[root@k8s-master01 ~]# chmod 755 /etc/sysconfig/modules/ipvs.modules && bash /etc/sysconfig/modules/ipvs.modules && lsmod | grep ip_vs

4.优化系统内核参数

[root@k8s-master01 ~]# cat > /etc/sysctl.d/k8s.conf <<EOF
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.ipv4.tcp_keepalive_time = 600
net.ipv4.tcp.keepaliv.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.top_timestamps = 0
net.core.somaxconn = 16384
EOF

#生效
[root@k8s-master01 ~]# sysctl -p

5.安装docker

[root@k8s-master01 ~]# yum-config-manager --add-repo https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo

[root@k8s-master01 ~]# yum install -y docker-ce-19.03.15

[root@k8s-master01 ~]# mkdir /etc/docker
[root@k8s-master01 ~]# cat > /etc/docker/daemon.json << EOF
{
  "registry-mirrors": ["https://dp0vxr93.mirror.aliyuncs.com"]
}
EOF

[root@k8s-master01 ~]# systemctl daemon-reload
[root@k8s-master01 ~]# systemctl start docker && systemctl enable docker

6.更新时区

[root@k8s-master01 ~]# ln -sf /usr/share/zoneinfo/Asia/Shanghai /etc/localtime && echo 'Asia/Shanghai' > /etc/timezone

7.安装kubernetes

1.添加kubernetes源
[root@k8s-master01 ~]# cat > /etc/yum.repos.d/kubernetes.repo <<EOF
[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

2.安装
[root@k8s-master01 ~]# yum install kubelet-1.21.3 kubeadm-1.21.3 kubectl-1.21.3 -y

3.启动
[root@k8s-master01 ~]# systemctl enable kubelet && systemctl start kubelet

#注意：未初始化或未加入节点，systemctl status kubelet 不显示 active (running)

二、master节点

#初始化
[root@k8s-master01 ~]# kubeadm init --image-repository=registry.cn-hangzhou.aliyuncs.com/k8sos  --kubernetes-version=v1.21.3 --service-cidr=10.96.0.0/12 --pod-network-cidr=10.244.0.0/16

#提示报错：可改可不改
	[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/
#查看
[root@k8s-master01 ~]# docker info | grep Cgroup
 Cgroup Driver: cgroupfs
#解决 
[root@k8s-master01 ~]# vim /usr/lib/systemd/system/docker.service
ExecStart=/usr/bin/dockerd -H fd:// --containerd=/run/containerd/containerd.sock --exec-opt native.cgroupdriver=systemd
#在该参数后添加  --exec-opt native.cgroupdriver=systemd


[root@k8s-master01 ~]# mkdir -p $HOME/.kube
[root@k8s-master01 ~]# cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
[root@k8s-master01 ~]# chown $(id -u):$(id -g) $HOME/.kube/config

[root@k8s-master01 ~]# rz flannel.yaml
[root@k8s-master01 ~]# kubectl apply -f flannel.yaml
[root@k8s-master01 ~]# kubectl get pods -n kube-system
NAME                                   READY   STATUS    RESTARTS   AGE
coredns-978bbc4b6-bbj8w                1/1     Running   0          41m
coredns-978bbc4b6-wtrkc                1/1     Running   0          41m
etcd-k8s-master01                      1/1     Running   4          41m
kube-apiserver-k8s-master01            1/1     Running   3          41m
kube-controller-manager-k8s-master01   1/1     Running   0          41m
kube-flannel-ds-jkr6t                  1/1     Running   0          100s
kube-proxy-qwc6f                       1/1     Running   0          41m
kube-scheduler-k8s-master01            1/1     Running   3          41m

flannel.yam文件地址 https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml

三、node节点

[root@k8s-node01 ~]# kubeadm join 10.0.0.81:6443 --token nngi3o.kvfvlwbacqhmgd7d --discovery-token-ca-cert-hash sha256:8348afc461f384d3c48ee2c904315e415cf6e813fc8b7ea8baa04e0eee243fb5

四、测试集群

[root@k8s-master01 ~]# kubectl get nodes
NAME           STATUS   ROLES                  AGE   VERSION
k8s-master01   Ready    control-plane,master   61m   v1.21.3
k8s-node01     Ready    <none>                 26m   v1.21.3

[root@k8s-master01 ~]# kubectl run test -it --rm --image=busybox:1.28.3
If you don't see a command prompt, try pressing enter.
/ # nslookup kubernetes
Server:    10.96.0.10
Address 1: 10.96.0.10 kube-dns.kube-system.svc.cluster.local

Name:      kubernetes
Address 1: 10.96.0.1 kubernetes.default.svc.cluster.local