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      <none>    30s       v1.11.3
       k8s-node2    Ready      <none>    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:       <none>
       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 <token> <master-ip>:<master-port> --discovery-token-ca-cert-hash sha256:<hash>

     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   <none>        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