使用Kubeadm 部署 K8S 1.17.1

设置系统主机名以及hosts文件

hostnamectl set-hostname master  
hostnamectl set-hostname node01  
hostnamectl set-hostname node02

​

修改hosts文件，master和node节点上都需要改

[root@master k8s]# cat /etc/hosts  
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4  
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6  
192.168.150.128 master  
192.168.150.129 node1  
192.168.150.130 node2

安装依赖包

yum -y install conntrack ntpdate ntp ipvsadm ipset jq iptables curl sysstat libseccomp wget vim net-tools git

设置防火墙为Iptables并清空规则

systemctl stop firewalld && systemctl disable firewalld && yum -y install iptables-services && \\  
systemctl start iptables && systemctl enable iptables && iptables -F && service iptables save 

关闭SELINUX、SWAP

swapoff -a && sed  -i '/swap/d' /etc/fstab && setenforce 0 && sed -i 's/enforcing/SELINUX=disabled/g' /etc/selinux/config

cat > /etc/sysctl.d/kubernetes.conf << EOF  
net.bridge.bridge-nf-call-ip6tables = 1  
net.bridge.bridge-nf-call-iptables = 1  
net.ipv4.ip_forward = 1  
net.ipv4.tcp_tw_recycle=0  

调整内核参数，对于K8S

#禁止使用swap空间，只有当系统OOM时才允许使用它  
vm.swappiness = 0  
#不检查物理内存是否够用  
vm.overcommit_memory=1   
fs.inotify.max_user_instances=8192  
fs.inotify.max_user_watches=1048576  
fs.file-max=52706963  
fs.nr_open=52706963  
net.ipv6.conf.all.disable_ipv6=1  
net.netfilter.nf_conntrack_max=2310720 #4.0内核可以设置这个参数  
EOF  
​  
sysctl -p /etc/sysctl.d/kubernetes.conf

设置系统时区为上海

timedatectl set-timezone Asia/Shanghai  
#将当前的UTC时间写入硬件时钟  
timedatectl set-local-rtc 0  

重启依赖于系统时间的服务

systemctl restart rsyslog  
systemctl restart crond

关闭不需要的服务

systemctl stop postfix && systemctl disable postfix

设置rsyslogd和systemd journald

mkdir /var/log/journal  
mkdir /etc/systemd/jorunald.conf.d  
cat > /etc/systemd/jorunald.conf.d/99-prophet.conf << EOF  
[Journal]  
Storage=persistent  
Compress=yes  
SyncIntervalSec=5m  
RateLimitInterval=30s  
RateLimitBurst=1000  
#最大占用空间  
SystemMaxUse=10G  
#单日志文件最大大小 
SystemMaxFileSize=200M  
#日志保存时间2周  
MaxRetentionSec=2week  
#不将日志转发到syslog  
ForwardToSyslog=no  
EOF  
systemctl restart systemd-journald 

​升级系统内核为4.44版本

#CentOS7.x系统自带的3.10.x内核存在一些Bug，导致运行的Docker、Kubernetes不稳定
rpm -Uvh http://www.elrepo.org/elrepo-release-7.0-3.el7.elrepo.noarch.rpm   
# 安装完成后检查/boot/grub2/grub.cfg 中对应内核menuentry中是否包含initrd16配置，如果没有，再安装一次  
​  
yum --enablerepo=elrepo-kernel install -y kernel-lt  
​  
# 设置开机从新内核启动  
grub2-set-default "CentOS Linux (4.4.182-1.el7.elrepo.x86\_64) 7 (Core)"

kube-rpoxy开启ipvs的前置条件

modprobe br_netfilter  
​  
cat > /etc/sysconfig/modules/ipvs.modules << EOF  
#!/bin/bash  
modprobe -- ip_vs  
modprobe -- ip_vs_rr  
modprobe -- ip_vs_wrr  
modprobe -- ip_vs_sh  
modprobe -- nf_conntrack_ipv4  
EOF  
​  
chmod 755 /etc/sysconfig/modules/ipvs.modules && bash /etc/sysconfig/modules/ipvs.modules  && lsmod | grep -e ip_vs -e nf_conntrack_ipv4

安装Docker

yum -y install yum-utils device-mapper-persistent-data lvm2   
yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo  
​  
yum -y update && yum -y install docker-ce   
## 创建docker配置目录  
mkdir /etc/docker  
​  
#配置daemon  
cat > /etc/docker/daemon.json << EOF  
{  
 "exec-opts": ["native.cgroupdriver=systemd"],  
 "log-driver": "json-file",  
 "log-opts": {  
 "max-size": "100m"  
 },  
 "registry-mirrors": ["https://docker.mirrors.ustc.edu.cn/"]  
}  
EOF  
​  
​  
mkdir -p /etc/systemd/system/docker.service.d  
​  
# 启动docker  
systemctl daemon-reload && systemctl start docker && systemctl enable docker  
​

安装kubeadm（每个节点都需要安装）

# 导入阿里云kubeadm镜像仓库  
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  
​  
# 安装  
yum -y install kubeadm-1.15.1 kubectl-1.15.1 kubelet-1.15.1  
​  
# 设置开机自启动  
systemctl enable kubelet.service 

镜像下载

因为在国内访问不了google的docker仓库，但是我们可以在阿里云上找到需要的镜像，下载下来，然后重新打上标签即可，可以使用下面的脚本下载所需镜像

镜像下载地址 https://cr.console.aliyun.com/images/cn-hangzhou/google_containers/kube-apiserver-amd64/detail

下面是镜像下载脚本：

#!/bin/bash    
image_aliyun=(kube-apiserver-amd64:v1.17.1 kube-controller-manager-amd64:v1.17.1 kube-scheduler-amd64:v1.17.1 kube-proxy-amd64:v1.17.1 pause-amd64:3.1 etcd-amd64:3.4.3-0 coredns:1.6.5)  
​  
for image in ${image_aliyun[@]}  
​  
do  
 docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/$image  
 docker tag  registry.cn-hangzhou.aliyuncs.com/google_containers/$image k8s.gcr.io/${image/-amd64/}  
 docker rmi registry.cn-hangzhou.aliyuncs.com/google_containers/$image  
done

初始化主节点

生成默认配置yaml配置文件，生成之后需要修改一些配置  
kubeadm config print init-defaults > kubeadm-config.yaml  
​  
​  
# 修改advertiseAddress为master节点IP  
# 修改kubernetesVersion: v1.17.1  
# 在serviceSubnet: 10.96.0.0/12上面添加一行 podSubnet: "10.244.0.0/16" 原因是flanne默认网段就是这个网段  
​  
# 在配置文件最后添加下面的字段,将默认的调度方式改为ipvs  
---  
apiVersion: kubeproxy.config.k8s.io/v1alpha1  
kind: KubeProxyConfiguration  
featureGates:  
 SupportIPVSProxyMode: true  
mode: ipvs  
​  
# 安装以及自动颁发证书  
kubeadm init --config=kubeadm-config.yaml  | tee kubeadm-init.log 

成功安装之后的部分提示信息

# cat kubeadm-init.log   
...  
[addons] Applied essential addon: kube-proxy  
​  
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  
​  
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/  
​  
Then you can join any number of worker nodes by running the following on each as root:  
​  
kubeadm join 192.168.175.133:6443 --token 6bu2e9.heokh2kwn5h2eph1 --discovery-token-ca-cert-hash sha256:5382721c5a684d10d2d43a6a825af039c044c4dda46c4d49dd64d2f41ffa6c97   
...

成功安装之后的操作

 mkdir -p $HOME/.kube # 该目录用于保存kubectl 和kubeapi的连接缓存以及认证文件  
 sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config  
 sudo chown $(id -u):$(id -g) $HOME/.kube/config

部署网络

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

查看集群节点状态

kubectl get nodes 
kubectl get cs
kubectl get pod -n kube-system

保存重要文件

mkdir k8sInstall
mv kubeadm-config.yaml  kubeadm-init.log  k8sInstall

node节点加入集群方法

kubeadm join MasterIP:6443 --token wyy67p.9wmda1iw4o8ds0c5 --discovery-token-ca-cert-hash sha256:3de3e4401de1cdf3b4c778ad1ac3920d9f7b15ca34b4c5ebe44d92e60d1290e0 #token和cert hash需要修改为你的配置，可以在kubeadm-init.log 中找到