Kubeadm可帮助你快速部署一套kubernetes集群。kubeadm设计目的为新用户开始尝试kubernetes提供一种简单的方法。
这个工具能通过两条指令完成一个kubernetes的部署:
# 创建一个Master节点
$ kubeadm init
# 将一个 Node 节点加入到当前集群中
$ kubeadm join <Master节点的IP和端口>
1.安装要求
在开始之前,部署Kubernetes集群机器需要满足一下几个条件:
一台或多台运行deb/rpm兼容操作系统的机器,例如ubuntu或CentOS
硬件配置:2GB或更多RAM,2个CPU或更多CPU,硬盘30GB或更多
集群中所有机器之间网络互通
可以访问外网,需要拉取镜像
禁止swap分区
2.学习目标
在所有节点上安装Docker和kubeadm
部署Kubernetes Master
部署容器网络插件
部署Kubernetes Node,将节点加入Kubernetes集群中
部署Dashboard Web页面,可视化查看Kubernetes资源
3.准备环境
关闭防火墙:
$ systemctl stop firewalld
$ systemctl disable firewalld
关闭selinux:
$ sed -i -r “/^SELINUX=/c SELINUX=disabled” /etc/selinux/config
$ setenforce 0
关闭swap:
$ swapoff -a // 临时
$ sed -ri ‘s/.swap./#&/’ /etc/fstab // 永久关闭swap
添加主机名与IP对应关系(记得设置主机名):
$ cat /etc/hosts
192.168.36.18 k8s-master
192.168.36.19 k8s-node1
192.168.36.20 k8s-node2
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
4. 所有节点安装Docker/kubeadm/kubelet
Kubernetes默认CRI(容器运行时)为Docker,因此先安装Docker。
4.1 安装Docker
$ wget https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo -O /etc/yum.repos.d/docker-ce.repo
$ yum install -y http://mirror.centos.org/centos/7/extras/x86_64/Packages/container-selinux-2.107-3.el7.noarch.rpm
$ 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
4.2 添加阿里云YUM软件源
$ 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
gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF
4.3 安装kubeadm,kubelet和kubectl
由于版本更新频繁,这里指定版本号部署:
$ yum install -y kubelet-1.17.3 kubeadm-1.17.3 kubectl-1.17.3
$ systemctl enable kubelet
5. 部署Kubernetes Master
在192.168.36.18(Master)执行。
$ kubeadm init \
–apiserver-advertise-address=192.168.36.18 \
–image-repository registry.aliyuncs.com/google_containers \
–kubernetes-version v1.17.3 \
–service-cidr=10.1.0.0/16 \
–pod-network-cidr=10.244.0.0/16
开机启动:systemctl enable kubelet.service
![图片[1]-K8S快速搭建-](https://fbi.kim/wp-content/uploads/2019/12/image-79.png)
使用kubectl工具:
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
![图片[2]-K8S快速搭建-](https://fbi.kim/wp-content/uploads/2019/12/image-80.png)
6. 安装Pod网络插件(CNI)
$ kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
若无法下载,附件: kube-flannel
![图片[3]-K8S快速搭建-](https://fbi.kim/wp-content/uploads/2019/12/image-81.png?x-oss-process=image/resize,m_fill,h_159,w_1024)
kubectl get pods -n kube-system
![图片[4]-K8S快速搭建-](https://fbi.kim/wp-content/uploads/2019/12/image-86.png)
确保能够访问到quay.io这个registery。
node节点执行:
docker pull quay.io/coreos/flannel:v0.11.0-amd64
如果下载失败,可以改成这个镜像地址:lizhenliang/flannel:v0.11.0-amd64
docker pull lizhenliang/flannel:v0.11.0-amd64
![图片[5]-K8S快速搭建-](https://fbi.kim/wp-content/uploads/2019/12/image-82.png)
7. 加入Kubernetes Node
在172.31.31.42 / 172.31.18.70(Node)执行。
docker pull quay.io/coreos/flannel:v0.11.0-amd64 (Master、Node都执行下载镜像!) :
$ kubeadm join 172.31.29.166:6443 –token r9pogn.sns9dnzxillqynh3 \
–discovery-token-ca-cert-hash sha256:7d359de7ac558825dd881f0e3ff7dda4663220d1d3f82917093b0e693338d916
![图片[6]-K8S快速搭建-](https://fbi.kim/wp-content/uploads/2019/12/image-85.png)
若出现下方报错,需执行更改驱动:
![图片[7]-K8S快速搭建-](https://fbi.kim/wp-content/uploads/2019/12/image-83.png?x-oss-process=image/resize,m_fill,h_80,w_1024)
# vi /etc/docker/daemon.json
{
“exec-opts”:[“native.cgroupdriver=systemd”]
}
查看加入Node验证:
![图片[8]-K8S快速搭建-](https://fbi.kim/wp-content/uploads/2019/12/image-84.png)
8. 测试kubernetes集群
在Kubernetes集群中创建一个pod,验证是否正常运行:
$ kubectl create deployment nginx –image=nginx
$ kubectl expose deployment nginx –port=80 –type=NodePort
$ kubectl get pod,svc
访问地址:http://NodeIP:Port
9. 部署 Dashboard
$ kubectl apply -f https://raw.githubusercontent.com/kubernetes/dashboard/v1.10.1/src/deploy/recommended/kubernetes-dashboard.yaml
默认镜像国内无法访问,修改镜像地址为: lizhenliang/kubernetes-dashboard-amd64:v1.10.1
默认Dashboard只能集群内部访问,修改Service为NodePort类型,暴露到外部:
kind: Service
apiVersion: v1
metadata:
labels:
k8s-app: kubernetes-dashboard
name: kubernetes-dashboard
namespace: kube-system
spec:
type: NodePort
ports:
– port: 443
targetPort: 8443
nodePort: 30001
selector:
k8s-app: kubernetes-dashboard
$ kubectl apply -f kubernetes-dashboard.yaml
访问地址:http://NodeIP:30001
创建service account并绑定默认cluster-admin管理员集群角色:
$ kubectl create serviceaccount dashboard-admin -n kube-system
$ kubectl create clusterrolebinding dashboard-admin --clusterrole=cluster-admin --serviceaccount=kube-system:dashboard-admin
$ kubectl describe secrets -n kube-system $(kubectl -n kube-system get secret | awk '/dashboard-admin/{print $1}')
使用输出的token登录Dashboard。(建议使用火狐浏览器登陆)