linux(centos8):安装kubernetes worker节点并加入到kubernetes集群(kubernetes 1.18.3)

一，安装kubernetes前的准备工作

安装前的准备工作(master\worker都要进行)

参见:

https://www.cnblogs.com/architectforest/p/13141743.html

说明:以上这些准备工作需要在worker 节点机器上操作一遍

kubernetes的master节点的安装(需在master节点机器上操作):

参见:

https://www.cnblogs.com/architectforest/p/13153053.html

演示例子说明：机器共两台:

master节点机器: ip: 192.168.219.130, hostname: kubemaster

woker 节点机器: ip: 192.168.219.136, hostname: node1

说明：刘宏缔的架构森林是一个专注架构的博客，地址：https://www.cnblogs.com/architectforest

对应的源码可以访问这里获取： https://github.com/liuhongdi/

说明：作者:刘宏缔邮箱: 371125307@qq.com

二，在worker节点安装kubernetes

1,新建kubernetes的repo

[root@node1 ~]# vi /etc/yum.repos.d/kubernetes.repo

内容:

[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

2,安装三大件:

[root@node1 ~]# dnf install kubectl kubelet kubeadm

安装完成后查看版本:

[root@node1 ~]# kubelet --version

Kubernetes v1.18.3

[root@node1 ~]# kubeadm version

kubeadm version: &version.Info{Major:"1", Minor:"18", GitVersion:"v1.18.3", GitCommit:"2e7996e3e2712684bc73f0dec0200d64eec7fe40", 
GitTreeState:"clean", BuildDate:"2020-05-20T12:49:29Z", GoVersion:"go1.13.9", Compiler:"gc", Platform:"linux/amd64"}

[root@node1 ~]# kubectl version

Client Version: version.Info{Major:"1", Minor:"18", GitVersion:"v1.18.3", GitCommit:"2e7996e3e2712684bc73f0dec0200d64eec7fe40",
 GitTreeState:"clean", BuildDate:"2020-05-20T12:52:00Z", GoVersion:"go1.13.9", Compiler:"gc", Platform:"linux/amd64"}

The connection to the server localhost:8080 was refused - did you specify the right host or port?

3,使kubelet服务可以自启动

[root@node1 ~]# systemctl enable kubelet

三，把worker节点加入到cluster

1,得到join命令：要在master节点上执行:

[root@kubemaster ~]# kubeadm token create --print-join-command

W0618 15:07:30.243762  115106 configset.go:202] WARNING: kubeadm cannot validate component configs 
for API groups [kubelet.config.k8s.io kubeproxy.config.k8s.io]

kubeadm join 192.168.219.130:6443 --token cts238.khb7z4qwu1h6iens     \
--discovery-token-ca-cert-hash sha256:c718e29ccb1883715489a3fdf53dd810a7764ad038c50fd62a2246344a4d9a73

worker节点的ip要加入到master节点的防火墙:

[root@kubemaster ~]# firewall-cmd --permanent --zone=trusted --add-source=192.168.219.136

success

[root@kubemaster ~]# firewall-cmd --reload

success

2,回到worker节点上执行:

[root@node1 ~]# kubeadm join 192.168.219.130:6443 --token cts238.khb7z4qwu1h6iens     \
--discovery-token-ca-cert-hash sha256:c718e29ccb1883715489a3fdf53dd810a7764ad038c50fd62a2246344a4d9a73

看到如下信息表示加入到cluster成功:

This node has joined the cluster:

* Certificate signing request was sent to apiserver and a response was received.

* The Kubelet was informed of the new secure connection details.

Run 'kubectl get nodes' on the control-plane to see this node join the cluster.

3,查看woker节点上新增加的image

[root@node1 ~]# docker images

REPOSITORY                                           TAG                 IMAGE ID            CREATED             SIZE

calico/node                                          v3.14.1             04a9b816c753        3 weeks ago         263MB

calico/pod2daemon-flexvol                            v3.14.1             7f93af2e7e11        3 weeks ago         112MB

calico/cni                                           v3.14.1             35a7136bc71a        3 weeks ago         225MB

registry.aliyuncs.com/google_containers/kube-proxy   v1.18.3             3439b7546f29        4 weeks ago         117MB

registry.aliyuncs.com/google_containers/pause        3.2                 80d28bedfe5d        4 months ago        683kB

4,备注:

error execution phase preflight: couldn't validate the identity of the API Server: 
could not find a JWS signature in the cluster-info ConfigMap for token ID “xgt21h"

这个错误提示表示token已过期

四，在master节点上查看node

[root@kubemaster ~]# kubectl get nodes

NAME         STATUS   ROLES    AGE     VERSION

kubemaster   Ready    master   26h     v1.18.3

node1        Ready    <none>   2m57s   v1.18.3

已经看到了node1节点，说明加入到cluster成功

五,在master和node1节点上安装一个nginx容器，并查看效果:

编辑rc文件

[root@kubemaster k8s]# vi nginx-rc.yaml

内容:

apiVersion: v1

kind: ReplicationController

metadata:

  name: nginx-demo

spec:

  replicas: 2

  selector:

    app: nginx-demo

  template:

    metadata:

      labels:

        app: nginx-demo

    spec:

      containers:

      - name: nginx-demo

        image: nginx

        ports:

        - containerPort: 80

创建rc

[root@kubemaster k8s]# kubectl apply -f nginx-rc.yaml

replicationcontroller/nginx-demo created

查看效果:

[root@kubemaster k8s]# kubectl get pods -o wide

NAME               READY   STATUS    RESTARTS   AGE   IP               NODE    NOMINATED NODE   READINESS GATES

nginx-demo-b5vwt   1/1     Running   0          15m   172.16.141.16   node1   <none>           <none>

nginx-demo-j8n7d   1/1     Running   0          15m   172.16.141.13   node1   <none>           <none>

用curl访问(注意此处要到worker节点node1上访问):

[root@node1 ~]# curl http://172.16.141.13

<!DOCTYPE html>

<html>

<head>

<title>Welcome to nginx!</title>

<style>

    body {

        width: 35em;

        margin: 0 auto;

        font-family: Tahoma, Verdana, Arial, sans-serif;

    }

</style>

</head>

<body>

<h1>Welcome to nginx!</h1>

<p>If you see this page, the nginx web server is successfully installed and

working. Further configuration is required.</p>

<p>For online documentation and support please refer to

<a href="http://nginx.org/">nginx.org</a>.<br/>

Commercial support is available at

<a href="http://nginx.com/">nginx.com</a>.</p>

<p><em>Thank you for using nginx.</em></p>

</body>

</html>

生成service文件

[root@kubemaster k8s]# vi nginx-svc.yaml

内容:

apiVersion: v1

kind: Service

metadata:

  name: nginx-demo

spec:

  type: NodePort

  ports:

   - port: 80

     nodePort: 30020

  selector:

    app: nginx-demo

创建service

[root@kubemaster k8s]# kubectl apply -f nginx-svc.yaml

service/nginx-demo created

从浏览器访问服务:(说明：192.168.219.136是woker节点node1的ip)

六，查看kubernetes的版本

[root@kubemaster ~]# kubelet --version

Kubernetes v1.18.3

[root@kubemaster ~]# kubeadm version

kubeadm version: &version.Info{Major:"1", Minor:"18", GitVersion:"v1.18.3", GitCommit:"2e7996e3e2712684bc73f0dec0200d64eec7fe40",
 GitTreeState:"clean", BuildDate:"2020-05-20T12:49:29Z", GoVersion:"go1.13.9", Compiler:"gc", Platform:"linux/amd64”}

七，查看linux的版本

[root@kubemaster ~]# cat /etc/redhat-release

CentOS Linux release 8.2.2004 (Core)

[root@kubemaster ~]# uname -r

4.18.0-193.el8.x86_64

巴特西