从零开始离线安装k8s集群

本文主要用于在内网（离线）环境安装k8s集群；linux环境 centos7.6

主要步骤有：

安装docker
创建dokcer 私有镜像库 registry
安装kubernetes
安装flannel

1.离线安装docker

下载离线安装包https://download.docker.com/linux/centos/7/x86_64/stable/Packages/

docker-ce-cli-18.09.7-3.el7.x86_64.rpm

docker-ce-18.09.7-3.el7.x86_64.rpm

container-selinux-2.107-1.el7_6.noarch.rpm

containerd.io-1.2.2-3.el7.x86_64.rpm

上传到指定服务器，安装命令 rpm -ivh *.rpm
docker info 查看docker信息
修改cgoupdriver为systemd与k8b保持一致，vim /etc/docker/daemon.json

{

"registry-mirrors": ["https://registry.docker-cn.com"],

"exec-opts": ["native.cgroupdriver=systemd"]

}

systemctl daemon-reload
systemctl restart docker
设置开机启动 systemctl enabel docker

2.创建dokcer 私有镜像库 registry

1.在有外网环境的docker中下载镜像，并启动；

docker pull registry:2

2.从image导出镜像

docker save -o registry.tar registry:2

3.上传registry.tar到离线服务器，导入

docker load -I registry

4.启动

docker run -d -v /registry:/var/lib/registry -p 5000:5000 --restart=always --name registry registry:2

5.修改k8s集群节点的dokcer daemon.json 支持https

{

"registry-mirrors": ["https://registry.docker-cn.com"],

"exec-opts": ["native.cgroupdriver=systemd"],

"insecure-registries": ["10.209.68.12:5000"]

}

systemctl daemon-reload

systemctl restart docker

3.安装k8s

环境准备

关闭防火墙、SeLinux、swap

# 在 master 节点和 worker 节点都要执行

systemctl stop firewalld

systemctl disable firewalld

setenforce 0

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

# 关闭 swap

swapoff -a

yes | cp /etc/fstab /etc/fstab_bak

cat /etc/fstab_bak |grep -v swap > /etc/fstab

hostnamectl set-hostname master

需要设置其他主机名称时，可将 master 替换为正确的主机名node1、node2即可。

配置内核参数，将桥接的IPv4流量传递到iptables的链

cat > /etc/sysctl.d/k8s.conf <<EOF

net.bridge.bridge-nf-call-ip6tables = 1

net.bridge.bridge-nf-call-iptables = 1

EOF

sysctl –system

2，安装kubeadm/kubectl/kubelet

在有网络的服务器上下载需要的rpm安装包

配置kubeadm源

# cat <<EOF > /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

EOF

yum install --downloadonly --downloaddir=/home/centos/k8s kubeadm kubectl kubelet
上传rpm包到离线服务器安装

rpm -ivh *.rpm

设置开机启动 systemctl enable kubelet.service

获取镜像列表

# kubeadm config images list

k8s.gcr.io/kube-apiserver:v1.18.0

k8s.gcr.io/kube-controller-manager:v1.18.0

k8s.gcr.io/kube-scheduler:v1.18.0

k8s.gcr.io/kube-proxy:v1.18.0

k8s.gcr.io/pause:3.2

k8s.gcr.io/etcd:3.4.3-0

k8s.gcr.io/coredns:1.6.7

离线镜像

编写脚本，从阿里云下载镜像

# cat pull-images.sh

#!/bin/bash

images=(

kube-apiserver:v1.18.0

kube-controller-manager:v1.18.0

kube-scheduler:v1.18.0

kube-proxy:v1.18.0

pause:3.2

etcd:3.4.3-0

coredns:1.6.7

)

for imageName in ${images[@]};

docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/${imageName}

docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/${imageName} k8s.gcr.io/${imageName}

docker rmi registry.cn-hangzhou.aliyuncs.com/google_containers/${imageName}

done

执行脚本，然后查看镜像

# docker images

REPOSITORY TAG IMAGE ID CREATED SIZE

k8s.gcr.io/kube-proxy v1.18.0 43940c34f24f 7 days ago 117MB

k8s.gcr.io/kube-apiserver v1.18.0 74060cea7f70 7 days ago 173MB

k8s.gcr.io/kube-controller-manager v1.18.0 d3e55153f52f 7 days ago 162MB

k8s.gcr.io/kube-scheduler v1.18.0 a31f78c7c8ce 7 days ago 95.3MB

k8s.gcr.io/pause 3.2 80d28bedfe5d 6 weeks ago 683kB

k8s.gcr.io/coredns 1.6.7 67da37a9a360 2 months ago 43.8MB

k8s.gcr.io/etcd 3.4.3-0 303ce5db0e90 5 months ago

打包镜像

编写脚本打包镜像

# cat save-images.sh

#!/bin/bash

images=(

kube-apiserver:v1.18.0

kube-controller-manager:v1.18.0

kube-scheduler:v1.18.0

kube-proxy:v1.18.0

pause:3.2

etcd:3.4.3-0

coredns:1.6.7

)

for imageName in ${images[@]};

docker save -o `echo ${imageName}|awk -F ':' '{print $1}'`.tar k8s.gcr.io/${imageName}

done

压缩下载，上传到离线服务器；

tar czvf kubeadm-images-1.18.0.tar.gz *.tar

导入镜像

在安装节点分别导入离线镜像或者放入私有仓库使用

# cat load-image.sh

#!/bin/bash

ls /root/kubeadm-images-1.18.0 > /root/images-list.txt

cd /root/kubeadm-images-1.18.0

for i in $(cat /root/images-list.txt)

docker load -i $i

done

导入镜像

# ./load-image.sh

3，初始化master节点

kubeadm init --apiserver-advertise-address 10.209.69.12 --apiserver-bind-port 6443 --kubernetes-version 1.18.0 --pod-network-cidr 10.244.0.0/16 --service-cidr 10.1.0.0/16

mkdir -p $HOME/.kube

sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config

sudo chown $(id -u):$(id -g) $HOME/.kube/config

4，加入子节点

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

kubeadm join 10.209.69.12:6443 --token voj8z6.ytej05mfnul5gci7 \

--discovery-token-ca-cert-hash sha256:d12c6150f5752238e8eabe81403ff4defaf2aeb1a1c159ed7310e027b367b57b

安装flannel

下载https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml文件

把里面依赖的image都在有网络环境中下载下来；

导入私有镜像库；

docker tag xxx:vxxx 10.209.69.12:5000/xxx:vxxx

docker push 10.209.69.12:5000/xxx:vxxx

修改yml中镜像为私有镜像库中的包

部署

kubectl apply -f flannel.yml

查看节点是否为ready

kubectl get nodes