安装kubernetes

1. 安装好3台虚拟机
   1. 10.20.2.194[k8s-master]
   2. 10.20.2.44[k8s-node1]
   3. 10.20.2.37[k8s-node2]
2.  基本配置，master和各个node都需要配置
   • 修改hostname
     vim /etc/hostname
     hostnamectl set-hostname k8s-master|k8s-node1|k8s-node2|…|k8s-noden
   • 关闭selinux
     vi /etc/sysconfig/selinux
     SELINUX=disabled
   • 直接关闭防火墙
     systemctl stop firewalld.service #停止firewall
     systemctl disable firewalld.service #禁止firewall开机启动
   • 永久关闭swap—避免重启服务器后kubectl服务无法启动的问题
     在/etc/fstab 里面找的 带有swap的一行，把他注释或者删除都可以，注释安全些。
     vim /etc/fstab
     修改后保存退出
   • 关闭swap命令
     swapoff -a
   • 安装docker-ce仓库
     sudo yum-config-manager –add-repo https://download.docker.com/linux/centos/docker-ce.repo
   • 安装docker相关，并且版本号为17.12.0.ce，匹配使用的kubernetes 
     yum install net-tools nfs-utils telnet vim docker-ce-17.12.0.ce-1.el7.centos -y
     systemctl start docker && systemctl enable docker
   • 验证
     [root@k8s-master shell]# docker version
     Client:
     Version: 17.12.0-ce
     API version: 1.35
     Go version: go1.9.2
     Git commit: c97c6d6
     Built: Wed Dec 27 20:10:14 2017
     OS/Arch: linux/amd64
     
     Server:
     Engine:
     Version: 17.12.0-ce
     API version: 1.35 (minimum version 1.12)
     Go version: go1.9.2
     Git commit: c97c6d6
     Built: Wed Dec 27 20:12:46 2017
     OS/Arch: linux/amd64
     Experimental: false
   • 上传所需要的kubernetes文件，到/opt下，并解压
3. master上执行（到上传的kubernetes文件解压后的文件夹第一层中）
   cd shell && sh init.sh && sh master.sh
   • 一般来说会成功的
   • 继续执行以下命令
     mkdir -p $HOME/.kube
     sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
     sudo chown $(id -u):$(id -g) $HOME/.kube/config
   • 记住安装完输出的一条命令：
     kubeadm join 10.20.2.194:6443 –token xie4h6.ariunlewb0qypf5v –discovery-token-ca-cert-hash sha256:4e9c3197ccf30d47cdf70afb975b8b7d0d0a77630a26c1fcd673c49c8739e143
   • 至此，master节点安装完成！
4. 在每一个node节点上执行（到上传的kubernetes文件解压后的文件夹第一层中）
   cd shell && sh init.sh
   • 一般来说会成功的
   • 继续执行之前在master节点得到的join命令
     kubeadm join 10.20.2.194:6443 –token xie4h6.ariunlewb0qypf5v –discovery-token-ca-cert-hash sha256:4e9c3197ccf30d47cdf70afb975b8b7d0d0a77630a26c1fcd673c49c8739e143
   • 完事之后，到master节点上执行kubectl get nodes，即可看到已注册的node节点
     [root@k8s-master shell]# kubectl get nodes
     NAME STATUS ROLES AGE VERSION
     k8s-master Ready master 7m v1.11.3
     k8s-node1 Ready 30s v1.11.3
     k8s-node2 Ready 4s v1.11.3
5. 至此整个集群搭建完毕
6. 使用https访问master的32000端口，使用令牌的方式登录
   https://10.20.2.194:32000
7. 为dashboard创建用户，并生成令牌 
   • 创建dashboard管理用户
     kubectl create serviceaccount dashboard-admin -n kube-system
   • 绑定用户为集群管理用户
     kubectl create clusterrolebinding dashboard-cluster-admin –clusterrole=cluster-admin –serviceaccount=kube-system:dashboard-admin
   • 获取tocken
     kubectl describe secret -n kube-system dashboard-admin
   • 效果如下：
     [root@k8s-master dashboard]# kubectl create serviceaccount dashboard-admin -n kube-system
     serviceaccount/dashboard-admin created
     [root@k8s-master dashboard]# kubectl create clusterrolebinding dashboard-cluster-admin –clusterrole=cluster-admin –serviceaccount=kube-system:dashboard-admin
     clusterrolebinding.rbac.authorization.k8s.io/dashboard-cluster-admin created
     [root@k8s-master dashboard]# kubectl describe secret -n kube-system dashboard-admin-token-l7kpn
     Error from server (NotFound): secrets “dashboard-admin-token-l7kpn” not found
     [root@k8s-master dashboard]# kubectl describe secret -n kube-system dashboard-admin
     Name: dashboard-admin-token-ltcr7
     Namespace: kube-system
     Labels:
     Annotations: kubernetes.io/service-account.name=dashboard-admin
     kubernetes.io/service-account.uid=002635bb-1106-11e9-a723-000c29023ca2
     
     Type: kubernetes.io/service-account-token
     
     Data
     ====
     ca.crt: 1025 bytes
     namespace: 11 bytes
     token: eyJhbGciOiJSUzI1NiIsImtpZCI6IiJ9.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.FzeJOWlH5ugUDqPUErLWfbW_vqq-3wuBeY77v74Bm6Wl4a1Fv_2pMJoB7mQomVfvXegmg6_ISvrrm0mJ4f2DZC8SSUTMDEDLhgnrLAdHeuLJ82ZX04Oh7Pu9uFEVhHJc2rHBWX6tqyQ-rVLyGJsxM7R7L0FntXZ25uUWujwktegRzRXcMG30tnopsEQTx1fzb_47IygXRbGoiy2p1mGpOHlElqoGRvy6le5eLl38CPpuxQJbRUWFbpLsQV1Umcy4WPy1aifD2_q-l81eSRi4D0oxM1yuPksEq3ZdaYN4SYao1zdx_8D_CQwzESZ9-w4njGVbT5lkQbL4xkN2X4pP7g
   • 使用上面的token登录即可

    

8. 忘记node节点join到master节点的命令怎么办？
   • 基本命令
     kubeadm join –token : –discovery-token-ca-cert-hash sha256:
     1. <master-ip>:<master-port> ，本文这里对应得是10.20.2.194:6443
     2. token，一般token两天就过期了，如果过期了你需要重新创建（查看token命令是kubeadm token list，创建token命令是kubeadm token create)
        [root@k8s-master ~]# kubeadm token list
        TOKEN TTL EXPIRES USAGES DESCRIPTION EXTRA GROUPS
        xie4h6.ariunlewb0qypf5v 23h 2019-01-07T00:05:01+08:00 authentication,signing system:bootstrappers:kubeadm:default-node-token
        [root@k8s-master ~]# kubeadm token create
        5w6qwh.8n0ektfrjdct3ib4
     3. –discovery-token-ca-cert-hash，通过如下命令就可以得到
        [root@k8s-master ~]# openssl x509 -pubkey -in /etc/kubernetes/pki/ca.crt | openssl rsa -pubin -outform der 2>/dev/null | openssl dgst -sha256 -hex | sed ‘s/^.* //‘
        4e9c3197ccf30d47cdf70afb975b8b7d0d0a77630a26c1fcd673c49c8739e143
     4. 这样就可以组成join命令了