Centos8安装K8s

1、安装 Docker

1. 添加依赖源

$ curl https://download.docker.com/linux/centos/docker-ce.repo -o /etc/yum.repos.d/docker-ce.repo

2. 安装Docker

$ yum -y install docker-ce

3. 设置Docker开机自启动

$ systemctl enable --now docker
$ systemctl enable docker.service

4. 设置阿里云镜像源加速

$ sudo mkdir -p /etc/docker
$ sudo tee /etc/docker/daemon.json <<-'EOF'
{
  "registry-mirrors": ["https://ie2mtbp8.mirror.aliyuncs.com"]
}
EOF
$ sudo systemctl daemon-reload
$ sudo systemctl restart docker

2、安装 K8s

1. 添加依赖源

$ 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=0
repo_gpgcheck=0
EOF

2. 安装kubeadm

$ yum install -y kubelet kubeadm kubectl

3. 设置Kubelet开机自启动

$ systemctl enable kubelet.service

4. 下载镜像

在墙外,需要科学上网

$ kubeadm config images pull

5. 禁用Swap

$ vim /etc/fstab
/dev/mapper/cl-swap    >> # /dev/mapper/cl-swap
$ echo vm.swappiness=0 >> /etc/sysctl.conf

6. Docker设置Systemd

$  vim /etc/docker/daemon.json
"exec-opts": ["native.cgroupdriver=systemd"]

7. 初始化

$ kubeadm init  --pod-network-cidr=10.11.0.0/16
$ mkdir -p $HOME/.kube
$ sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
$ sudo chown $(id -u):$(id -g) $HOME/.kube/config

8. 安装 flannel

$  kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml

9. master 允许调度

默认安装好后为master，并且有个taint不允许调度，如需master当作node可去除该taint即可

kubectl taint nodes --all node-role.kubernetes.io/master-

10. 修改端口范围

默认端口范围为30000-32767

修改配置文件 vim /etc/kubernetes/manifests/kube-apiserver.yaml
$  - command:
   - kube-apiserver
   # 添加如下一行
   - --service-node-port-range=1-65535 

11. 开启路由转发

$ vim /etc/sysctl.conf
net.ipv4.ip_forward = 1

2、K8s集群

1. join master

在其他服务器上安装kubeadm，然后安装master上init后的提示kubeadm join….

 kubeadm join 192.168.66.211:6443 --token ynw3rv.du4nm0ef6djh3293 --discovery-token-ca-cert-hash sha256:e639aa22ea901ab8956ea40069f36b30df72d9999b42144a610c73fa70485b2e

注意：token仅24小时有效，过期后需要重新生成，这里提供一个脚本在过期后一键生成

#!/bin/bash

if [ $EUID -ne 0 ];then
    echo "must be root (or sudo) to run this script"
    exit 1
fi

if [ $# != 1 ] ; then
    echo "must input a param master-hostname | master-ip-address"
    echo " e.g.: 192.168.66.66 or k8s.aispring.cloud"
    exit 1;
fi

token=`kubeadm token create`
cert_hash=`openssl x509 -pubkey -in /etc/kubernetes/pki/ca.crt | openssl rsa -pubin -outform der 2>/dev/null | openssl dgst -sha256 -hex | sed 's/^.* //'`

echo "Refer the following command to join kubernetes cluster:"
echo "kubeadm join $1:6443 --token ${token} --discovery-token-ca-cert-hash sha256:${cert_hash}"

./generate_join_master.sh 192.168.66.211