k8s学习(七)service的使用

一、Service Service 是对一组提供相同功能的 Pods 的抽象，并为它们提供一个统一的入口。借助 Service，应用可以方便的实现服务发现与负载均衡，并实现应用的零宕机升级。二、ClusterIP自动分配一个仅 cluster 内部可以访问的虚拟 IP1、nginx-service.yaml[root@k8s-master k8s]#

_lrs

415人浏览 · 2021-12-23 21:34:17

_lrs · 2021-12-23 21:34:17 发布

一、Service

Service 是对一组提供相同功能的 Pods 的抽象，并为它们提供一个统一的入口。借助 Service，应用可以方便的实现服务发现与负载均衡，并实现应用的零宕机升级。

二、ClusterIP

自动分配一个仅 cluster 内部可以访问的虚拟 IP

1、nginx-service.yaml

[root@k8s-master k8s]# cat nginx-service.yaml
---
apiVersion: v1
kind: Service
metadata:
  name: nginx-service
  labels:
    app: nginx-deployment-test-02
    name: nginx-service
    namespace: default
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
  selector:
    app: nginx-service
  sessionAffinity: None
  type: ClusterIP
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment-02
spec:
  replicas: 3
  selector:
    matchLabels:
      app: nginx-deployment-test-02
  template:
    metadata:
      labels:
        app: nginx-deployment-test-02
    spec:
      containers:
      - name: nginx-deployment-test-02
        image: nginx:1.20
        ports:
        - containerPort: 80

2、创建

[root@k8s-master k8s]# kubectl create -f nginx-service.yaml
service/nginx-service created
deployment.apps/nginx-deployment-02 created

3、查看

[root@k8s-master k8s]# kubectl get svc
NAME            TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)   AGE
kubernetes      ClusterIP   10.96.0.1        <none>        443/TCP   3d11h
nginx-service   ClusterIP   10.109.102.140   <none>        80/TCP    6s

[root@k8s-master k8s]# kubectl get deployments
NAME                  READY   UP-TO-DATE   AVAILABLE   AGE
nginx-deployment-02   3/3     3            3           41s

[root@k8s-master k8s]# kubectl get rs
NAME                             DESIRED   CURRENT   READY   AGE
nginx-deployment-02-565f47cc54   3         3         3       2m46s

[root@k8s-master k8s]# kubectl get pods
NAME                                   READY   STATUS    RESTARTS   AGE
nginx-deployment-02-565f47cc54-2mgrq   1/1     Running   0          3m19s
nginx-deployment-02-565f47cc54-5zz2l   1/1     Running   0          3m19s
nginx-deployment-02-565f47cc54-tmxjr   1/1     Running   0          3m19s

4、查看详细信息

[root@k8s-master k8s]# kubectl describe svc nginx-service
Name:              nginx-service
Namespace:         default
Labels:            app=nginx-deployment-test-02
                   name=nginx-service
                   namespace=default
Annotations:       <none>
Selector:          app=nginx-service
Type:              ClusterIP
IP Families:       <none>
IP:                10.109.102.140
IPs:               10.109.102.140
Port:              <unset>  80/TCP
TargetPort:        80/TCP
Endpoints:         <none>
Session Affinity:  None
Events:            <none>

5、访问 IP

访问nginx-service的ip

[root@k8s-master k8s]# curl  10.109.102.140:80
<!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>

三、NodePort

在 ClusterIP 基础上为 Service 在每台机器上绑定一个端口。

1、nginx-service-nodeport.yaml

[root@k8s-master k8s]# cat nginx-service-nodeport.yaml
---
apiVersion: v1
kind: Service
metadata:
  name: nginx-service-nodeport
  labels:
    app: nginx-deployment-test-03
    name: nginx-service-nodeport
    namespace: default
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
    nodePort: 32000
  selector:
    app: nginx-deployment-test-03
  type: NodePort
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment-03
spec:
  replicas: 3
  selector:
    matchLabels:
      app: nginx-deployment-test-03
  template:
    metadata:
      labels:
        app: nginx-deployment-test-03
    spec:
      containers:
      - name: nginx-deployment-test-03
        image: nginx:1.20
        ports:
        - containerPort: 80

2、创建

[root@k8s-master k8s]# kubectl create -f nginx-service-nodeport.yaml
service/nginx-service-nodeport created
deployment.apps/nginx-deployment-03 created

3、查看

[root@k8s-master k8s]# kubectl get svc
NAME                     TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)        AGE
kubernetes               ClusterIP   10.96.0.1       <none>        443/TCP        4d
nginx-service-nodeport   NodePort    10.106.65.70    <none>        80:32000/TCP   3m5s

[root@k8s-master k8s]# kubectl get deployment
NAME                  READY   UP-TO-DATE   AVAILABLE   AGE
nginx-deployment-03   3/3     3            3           2m34s

4、查看详细信息

[root@k8s-master k8s]# kubectl describe svc nginx-service-nodeport
Name:                     nginx-service-nodeport
Namespace:                default
Labels:                   app=nginx-deployment-test-03
                          name=nginx-service-nodeport
                          namespace=default
Annotations:              <none>
Selector:                 app=nginx-deployment-test-03
Type:                     NodePort
IP Families:              <none>
IP:                       10.106.65.70
IPs:                      10.106.65.70
Port:                     <unset>  80/TCP
TargetPort:               80/TCP
NodePort:                 <unset>  32000/TCP
Endpoints:                10.244.85.241:80,10.244.85.246:80,10.244.85.254:80
Session Affinity:         None
External Traffic Policy:  Cluster
Events:                   <none>

5、访问内部ip

[root@k8s-master k8s]# curl 10.106.65.70:80
<!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>

6、访问外部端口

访问虚拟机ip 172.16.10.158

[root@k8s-master k8s]# curl 172.16.10.158:32000
<!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>

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