一、docker环境搭建

1、移除以前docker相关包

sudo yum remove docker docker-client docker-client-latest docker-common docker-latest docker-latest-logrotate docker-logrotate docker-engine

2、配置yam源

sudo yum install -y yum-utils

sudo yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo

3、安装docker

sudo yum install -y docker-ce docker-ce-cli containerd.io

yum install -y docker-ce-20.10.7 docker-ce-cli-20.10.7 containerd.io-1.4.6

4、启动

systemctl enable docker --now

二、kubeadm创建集群

给每个节点设置主机名

hostnamectl set-hostname k8smaster

将 SELinux 设置为 permissive 模式（相当于将其禁用）

sudo setenforce 0
sudo sed -i 's/^SELINUX=enforcing$/SELINUX=permissive/' /etc/selinux/config

关闭swap

swapoff -a  
sed -ri 's/.*swap.*/#&/' /etc/fstab

允许 iptables 检查桥接流量

cat <<EOF | sudo tee /etc/modules-load.d/k8s.conf
br_netfilter
EOF

cat <<EOF | sudo tee /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF

配置生效

sudo sysctl --system

安装kubectl、kubeadm、kubectl

cat <<EOF | sudo tee /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=http://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=0
repo_gpgcheck=0
gpgkey=http://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg
   http://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
exclude=kubelet kubeadm kubectl
EOF

安装

sudo yum install -y kubelet-1.20.9 kubeadm-1.20.9 kubectl-1.20.9 --disableexcludes=kubernetes

启动kubelet

sudo systemctl enable --now kubelet

2、使用kubeadm引导集群

1、下载各个机器需要的镜像

sudo tee ./images.sh <<-'EOF'
#!/bin/bash
images=(
kube-apiserver:v1.20.9
kube-proxy:v1.20.9
kube-controller-manager:v1.20.9
kube-scheduler:v1.20.9
coredns:1.7.0
etcd:3.4.13-0
pause:3.2
)
for imageName in ${images[@]} ; do
docker pull registry.cn-hangzhou.aliyuncs.com/lfy_k8s_images/$imageName
done
EOF

chmod +x ./images.sh && ./images.sh

3、初始化主节点

给所有机器添加master域名映射，以下需要修改为自己的

echo "192.168.245.66 cluster-endpoint">> /etc/hosts

#主节点初始化

kubeadm init \
--apiserver-advertise-address=192.168.245.66 \
--control-plane-endpoint=cluster-endpoint \
--image-repository registry.cn-hangzhou.aliyuncs.com/lfy_k8s_images \
--kubernetes-version v1.20.9 \
--service-cidr=10.96.0.0/16 \
--pod-network-cidr=192.168.0.0/16

#所有网络范围不重叠

可能会遇到的问题：
在这里插入图片描述

1.Port 10259 is in use
/proc/sys/net/ipv4/ip_forward contents are not set to 1
参考链接
搭建kubenetes集群环境过程中遇到的问题

4、k8s安装成功后master节点会出现

在这里插入图片描述

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 control-plane nodes by copying certificate authorities
and service account keys on each node and then running the following as root:

  kubeadm join cluster-endpoint:6443 --token ibpnqm.enw3hmsxuw8uz7gx \
    --discovery-token-ca-cert-hash sha256:c98fd1b4c69a56dffc737c39f29c7f00b82ce16914c067440702f0994742467e \
    --control-plane 

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

kubeadm join cluster-endpoint:6443 --token ibpnqm.enw3hmsxuw8uz7gx \
    --discovery-token-ca-cert-hash sha256:c98fd1b4c69a56dffc737c39f29c7f00b82ce16914c067440702f0994742467e