kubeadmin 快速部署k8s集群

Posted on 2020-09-15,6 min read

安装要求
在开始之前,部署Kubernetes集群机器需要满足以下几个条件:
• 一台或多台机器,操作系统 CentOS7.x-86_x64
• 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
学习目标

  1. 在所有节点上安装Docker和kubeadm
  2. 部署Kubernetes Master
  3. 部署容器网络插件
  4. 部署 Kubernetes Node,将节点加入Kubernetes集群中
  5. 部署Dashboard Web页面,可视化查看Kubernetes资源
    准备环境
    kubernetes培训-kuberneters架构图.jpg
    关闭防火墙:
    $ systemctl stop firewalld
    $ systemctl disable firewalld
    $ iptables -F
    关闭selinux:
    $ sed -i "s/^SELINUX=enforcing/SELINUX=disabled/g" /etc/selinux/config
    $ sed -i "s/^SELINUX=permissive/SELINUX=disabled/g" /etc/selinux/config
    $ setenforce 0
    $ cat /etc/selinux/config

This file controls the state of SELinux on the system.

SELINUX= can take one of these three values:

enforcing - SELinux security policy is enforced.

permissive - SELinux prints warnings instead of enforcing.

disabled - No SELinux policy is loaded.

SELINUX=disabled

SELINUXTYPE= can take one of three two values:

targeted - Targeted processes are protected,

minimum - Modification of targeted policy. Only selected processes are protected.

mls - Multi Level Security protection.

SELINUXTYPE=targeted
关闭swap:
$ swapoff -a $ 临时
$ vim /etc/fstab $ 永久
$ sed -i 's/.swap./#&/' /etc/fstab
cat /etc/fstab

/etc/fstab

Created by anaconda on Mon Mar 4 17:23:04 2019

Accessible filesystems, by reference, are maintained under '/dev/disk'

See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info

/dev/mapper/centos-root / xfs defaults 0 0
UUID=3dd5660e-0905-4f1e-9fa3-9ce664d6eb94 /boot xfs defaults 0 0
/dev/mapper/centos-home /home xfs defaults 0 0
#/dev/mapper/centos-swap swap swap defaults 0 0
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
修改文件句柄限制
echo "* soft nofile 65536" >> /etc/security/limits.conf
echo "* hard nofile 65536" >> /etc/security/limits.conf
echo "* soft nproc 65536" >> /etc/security/limits.conf
echo "* hard nproc 65536" >> /etc/security/limits.conf
echo "* soft memlock unlimited" >> /etc/security/limits.conf
echo "* hard memlock unlimited" >> /etc/security/limits.conf
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。
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
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=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
导入gpgkey文件
$ wget https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg
$ rpm --import yum-key.gpg
$ wget https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
$ rpm --import rpm-package-key.gpg
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-1.13.3 kubeadm-1.13.3 kubectl-1.13.3 kubernetes-cni-0.6.0
$ systemctl enable kubelet
部署Kubernetes Master
由于默认拉取镜像地址k8s.gcr.io国内无法访问,这里指定阿里云镜像仓库地址。
$ kubeadm init
--apiserver-advertise-address=10.0.52.13
--image-repository registry.aliyuncs.com/google_containers
--kubernetes-version v1.13.3
--service-cidr=10.1.0.0/16
--pod-network-cidr=10.244.0.0/16
使用kubectl工具:
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown (idu):(id -u):(id -g) HOME/.kube/configPodCNIHOME/.kube/config 安装Pod网络插件(CNI) kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/a70459be0084506e4ec919aa1c114638878db11b/Documentation/kube-flannel.yml
确保能够访问到quay.io这个registery。
加入Kubernetes Node
向集群添加新节点,执行在kubeadm init输出的kubeadm join命令:
kubernetes培训-kubeadmin.png
kubeadm join 10.0.52.13:6443 --token nqg5gl.zr84xb63z2ve7dbn --discovery-token-ca-cert-hash sha256:3e43b9c41dd74ba0f46c260d0e0b6663993cf4563c3852384916d76338d6202e
在master执行
$ kubectl get nodes
kubernetes培训-nodes.png
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
部署 Dashboard
kubectl apply -f kubernetes-dashboard.yaml
kubectl apply -f admin-dashboard.yaml
访问地址:http://NodeIP:30001

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