其他分享
首页 > 其他分享> > 容器云平台No.3~kubernetes简单使用

容器云平台No.3~kubernetes简单使用

作者:互联网

容器云平台No.3~kubernetes简单使用

scofield 菜鸟运维杂谈

今天是是第三篇,接着上一篇继续

首先,通过kubectl可以看到,三个节点都正常运行



1[root@k8s-master001 ~]# kubectl  get no 
2NAME            STATUS   ROLES    AGE   VERSION
3k8s-master001   Ready    master   16h   v1.19.0
4k8s-master002   Ready    master   16h   v1.19.0
5k8s-master003   Ready    master   16h   v1.19.0

现在来部署第一个服务,这里以nginx为例



1[root@k8s-master001 ~]# kubectl  run  nginx --image=nginx --port=80
2pod/nginx created

可以看到,我们在k8s集群上创建了一个nginx应用,然后我们通过如下命令查看状态,发现现在nginx状态为Pending


1[root@k8s-master001 ~]# kubectl  get po
2NAME    READY   STATUS    RESTARTS   AGE
3nginx   0/1     Pending   0          7s

现在我们使用kubectl describe命令来查看更多信息


 1[root@k8s-master001 ~]# kubectl  describe po nginx
 2Name:         nginx
 3Namespace:    default
 4Priority:     0
 5Node:         <none>
 6Labels:       run=nginx
 7Annotations:  <none>
 8Status:       Pending
 9IP:           
10IPs:          <none>
11Containers:
12  nginx:
13    Image:        nginx
14    Port:         <none>
15    Host Port:    <none>
16    Environment:  <none>
17    Mounts:
18      /var/run/secrets/kubernetes.io/serviceaccount from default-token-6gd92 (ro)
19Conditions:
20  Type           Status
21  PodScheduled   False 
22Volumes:
23  default-token-6gd92:
24    Type:        Secret (a volume populated by a Secret)
25    SecretName:  default-token-6gd92
26    Optional:    false
27QoS Class:       BestEffort
28Node-Selectors:  <none>
29Tolerations:     node.kubernetes.io/not-ready:NoExecute op=Exists for 300s
30                 node.kubernetes.io/unreachable:NoExecute op=Exists for 300s
31Events:
32  Type     Reason            Age   From  Message
33  ----     ------            ----  ----  -------
34  Warning  FailedScheduling  15s         0/3 nodes are available: 3 node(s) had taint {node-role.kubernetes.io/master: }, that the pod didn't tolerate.
35  Warning  FailedScheduling  14s         0/3 nodes are available: 3 node(s) had taint {node-role.kubernetes.io/master: }, that the pod didn't tolerate.

从输出信息可以看到最隐藏后两个事件3 node(s) had taint {node-role.kubernetes.io/master: }, that the pod didn't tolerate.

什么意思呢?什么意思呢?

这个提示表示,没有节点可以接受调度。

为什么会这样呢?

因为我们现在三个节点都是master节点,还没有添加node节点。默认情况下,master打了污点(taint,后续再介绍),master节点不接收调度。
由于我们这里是测试环境,没有多余的机器来作为node节点,可以手动删除master的污点,让master节点接收调度。
通过如下命令可以查看taint信息:


 1[root@k8s-master001 ~]# kubectl get no -o yaml | grep taint -A 5
 2          f:taints: {}
 3      manager: kube-controller-manager
 4      operation: Update
 5      time: "2020-09-10T09:10:40Z"
 6    - apiVersion: v1
 7      fieldsType: FieldsV1
 8--
 9    taints:
10    - effect: NoSchedule
11      key: node-role.kubernetes.io/master
12  status:
13    addresses:
14    - address: 10.26.25.20
15--
16          f:taints: {}
17      manager: kube-controller-manager
18      operation: Update
19      time: "2020-09-10T09:30:25Z"
20    - apiVersion: v1
21      fieldsType: FieldsV1
22--
23    taints:
24    - effect: NoSchedule
25      key: node-role.kubernetes.io/master
26  status:
27    addresses:
28    - address: 10.26.25.21
29--
30          f:taints: {}
31      manager: kube-controller-manager
32      operation: Update
33      time: "2020-09-10T09:35:43Z"
34    - apiVersion: v1
35      fieldsType: FieldsV1
36--
37    taints:
38    - effect: NoSchedule
39      key: node-role.kubernetes.io/master
40  status:
41    addresses:
42    - address: 10.26.25.22

删除污点node-role.kubernetes.io/master,如下所示


1[root@k8s-master001 ~]# kubectl taint nodes --all node-role.kubernetes.io/master-
2node/k8s-master001 untainted
3node/k8s-master002 untainted
4node/k8s-master003 untainted

然后现在在看nginx的状态,已经变为ContainerCreating,这表示已经分配到节点,开始创建nginx的pod了


1[root@k8s-master001 ~]# kubectl  get po
2NAME    READY   STATUS              RESTARTS   AGE
3nginx   0/1     ContainerCreating   0          3m11s

使用kubectl get po -o wide查看,现在nginx已经正常运行了,而且可以看到,nginx现在被分配到 k8s-master001节点上,Pod IP是10.244.0.4


1[root@k8s-master001 ~]# kubectl  get po -o wide
2NAME    READY   STATUS    RESTARTS   AGE   IP           NODE            NOMINATED NODE   READINESS GATES
3nginx   1/1     Running   0          56m   10.244.0.4   k8s-master001   <none>           <none>

现在来访问nginx,熟悉的200出现了~~



 1[root@k8s-master001 ~]# curl -I  10.244.0.4
 2HTTP/1.1 200 OK
 3Server: nginx/1.19.2
 4Date: Fri, 11 Sep 2020 02:22:41 GMT
 5Content-Type: text/html
 6Content-Length: 612
 7Last-Modified: Tue, 11 Aug 2020 14:50:35 GMT
 8Connection: keep-alive
 9ETag: "5f32b03b-264"
10Accept-Ranges: bytes

但是如果在非集群节点上访问10.244.0.4,比如在自己的电脑上访问


1[~/b/] : curl -I 10.244.0.4

2curl: (55) getpeername() failed with errno 22: Invalid argument
容器云平台No.3~kubernetes简单使用

现在就来解决这个问题,


1、我们删掉原来创建的nginx pod


1[root@k8s-master001 ~]# kubectl  delete po nginx 
2pod "nginx" deleted

2、创建nginx.yaml文件


 1[root@k8s-master001 ~]# cat nginx.yaml 
 2---
 3apiVersion: apps/v1
 4kind: StatefulSet
 5metadata:
 6  name: nginx
 7  labels:
 8    app: nginx
 9spec:
10  serviceName: nginx
11  replicas: 1
12  selector:
13    matchLabels:
14      app: nginx
15  template:
16    metadata:
17      labels:
18        app: nginx
19    spec:
20      terminationGracePeriodSeconds: 180
21      containers:
22      - name: nginx
23        image: nginx
24        imagePullPolicy: Always
25        ports:
26        - containerPort: 80
27          name: port
28---
29apiVersion: v1
30kind: Service
31metadata:
32  name: nginx
33  labels:
34    app: nginx
35spec:
36  type: NodePort
37  ports:
38  - port: 80
39    targetPort: 80
40  selector:
41    app: nginx

3、执行kubectl apply -f nginx.yaml部署


 1[root@k8s-master001 ~]# kubectl  apply -f nginx.yaml 
 2statefulset.apps/nginx created
 3service/nginx created
 4
 5[root@k8s-master001 ~]# kubectl  get po,ep,svc
 6NAME          READY   STATUS    RESTARTS   AGE
 7pod/nginx-0   1/1     Running   0          24s
 8
 9NAME                   ENDPOINTS                                            AGE
10endpoints/kubernetes   10.26.25.20:6443,10.26.25.21:6443,10.26.25.22:6443   17h
11endpoints/nginx        10.244.2.3:80                                        23s
12
13NAME                 TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)        AGE
14service/kubernetes   ClusterIP   10.96.0.1       <none>        443/TCP        17h
15service/nginx        NodePort    10.106.27.213   <none>        80:30774/TCP   23s

现在能看到,创建了一个名为nginx的service,把nginx默认的80端口映射到了30774
访问集群任意节点的IP:32650,这里是10.26.25.20:30774

4、在集群节点上访问:


 1[root@k8s-master001 ~]# curl -I   10.26.25.20:30774
 2HTTP/1.1 200 OK
 3Server: nginx/1.19.2
 4Date: Fri, 11 Sep 2020 02:53:55 GMT
 5Content-Type: text/html
 6Content-Length: 612
 7Last-Modified: Tue, 11 Aug 2020 14:50:35 GMT
 8Connection: keep-alive
 9ETag: "5f32b03b-264"
10Accept-Ranges: bytes

5、在笔记本电脑上访问:


 1[~/b/wechatimages] : curl -I   10.26.25.20:30774
 2HTTP/1.1 200 OK
 3Server: nginx/1.19.2
 4Date: Fri, 11 Sep 2020 02:54:24 GMT
 5Content-Type: text/html
 6Content-Length: 612
 7Last-Modified: Tue, 11 Aug 2020 14:50:35 GMT
 8Connection: keep-alive
 9ETag: "5f32b03b-264"
10Accept-Ranges: bytes

如果您还是¥@@#¥……%#@

容器云平台No.3~kubernetes简单使用

可以先行了解kubernetes的pod,endpoint,service等概念。。。后续文章也会陆续讲到。。。
注:文中图片来源于网络,如有侵权,请联系我及时删除。

标签:容器,kubernetes,kubectl,nginx,No.3,master,k8s,master001
来源: https://blog.51cto.com/15060545/2657502