Centos7.9 部署搭建k8s集群

部署环境说明

两台centos7.9

一、环境准备

两台机器同时执行

# 关闭防火墙
systemctl stop firewalld
systemctl disable firewalld

# 关闭selinux
sed -i 's/enforcing/disabled/' /etc/selinux/config  # 永久
setenforce 0  # 临时

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

# 在master添加hosts
cat >> /etc/hosts << EOF
192.168.1.11 k8smaster
192.168.1.12 k8snode1
EOF

# 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  # 生效

# 时间同步
yum install ntpdate -y
ntpdate time.windows.com

两台机器分别执行

# 根据规划设置主机名
hostnamectl set-hostname <hostname>

二、安装docker

$ wget https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo -O /etc/yum.repos.d/docker-ce.repo
$ yum -y install docker-ce-18.06.1.ce-3.el7
$ systemctl enable docker && systemctl start docker
$ docker --version
Docker version 18.06.1-ce, build e68fc7a

三、安装kubeadm，kubelet和kubectl

公网参考

$ 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
gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF

$ yum install -y kubelet-1.18.0 kubeadm-1.18.0 kubectl-1.18.0
$ systemctl enable kubelet

内网可参考

https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64/Packages/?spm=a2c6h.25603864.0.0.38a8368fXNT5LI

下载如下包

image.png

因内网源安装报错7/kubernetes/packages-kubectl-1.18.0-0.x86_64.rpm: header v4 rsa/sha512 signature, key id 3e1ba8d5: nokey不得不出此下策
下载后安装（部分依赖内网源已经安装了）
yum localinstall -y *.rpm

四、部署Kubernetes Master

公网参考

$ kubeadm init \
  --apiserver-advertise-address=192.168.1.11 \
  --image-repository registry.aliyuncs.com/google_containers \
  --kubernetes-version v1.18.0 \
  --service-cidr=10.96.0.0/12 \
  --pod-network-cidr=10.244.0.0/16

无法访问registry.aliyuncs.com可以参考如下方法。

# 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

sh批量下载导入镜像

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 ${images[@]};
do
    docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/${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

查看下载镜像

# 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        288MB

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[@]};
do
    docker save -o `echo ${imageName}|awk -F ':' '{print $1}'`.tar k8s.gcr.io/${imageName}
done

# 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)
do
     docker load -i $i
done

导入镜像
# ./load-image.sh

五、kubeadm init

kubeadm init \
  --apiserver-advertise-address=192.168.117.58 \
  --kubernetes-version v1.18.0 \
  --service-cidr=10.96.0.0/12 \
  --pod-network-cidr=10.244.0.0/16 \
  --ignore-preflight-errors=Swap

成功后执行

mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
$ kubectl get nodes

在节点上执行提示的命令kubeadm join xxxxxx

节点执行k8s命令需要拷贝设置配置文件