Container Service for Kubernetes:Use an automatically created SLB instance to expose an application

Use the ACK console

1. Log on to the ACK console. In the left-side navigation pane, click Clusters.

2. On the Clusters page, find the cluster that you want to manage and click its name. In the left-side pane, choose Workloads > Deployments.

3. On the Deployments page, click Create from Image and configure the basic information, container settings, and advanced settings of the Deployment.

   1. On the Basic Information wizard page, specify Name, keep the default settings for other parameters, and click Next. In this example, the name is set to my-nginx.

   2. On the Container wizard page, specify the image name and container ports, keep the default settings for other parameters, and click Next.

      Parameter	Valid value
      Image Name	Click Select images. In the Select images and image tags dialog box, click the Artifact Center tab, search for nginx, and select the image repository named openanolis/nginx. Then, click Select Image Tag, set an image tag, and click OK.
      Port	Name: nginx. Container Port: 80.

   3. On the Advanced wizard page, keep the default settings and click Create to create an NGINX application.

Use kubectl

1. Create a file named my-nginx.yaml file and add the following YAML content to the file:

   apiVersion: apps/v1 # for versions before 1.8.0 use apps/v1beta1
   kind: Deployment
   metadata:
     name: my-nginx    # The name of the sample application. 
     labels:
       app: nginx
   spec:
     replicas: 2       # The number of replicated pods. 
     selector:
       matchLabels:
         app: nginx     # You must specify the same value in the selector of the Service that is used to expose the application. 
     template:
       metadata:
         labels:
           app: nginx
       spec:
       #  nodeSelector:
       #    env: test-team
         containers:
         - name: nginx
           image: anolis-registry.cn-zhangjiakou.cr.aliyuncs.com/openanolis/nginx:1.14.1-8.6
           ports:
           - containerPort: 80                                # The port that you want to expose in the Service.

2. Run the following command to deploy the my-nginx application:

   kubectl apply -f my-nginx.yaml

3. Run the following command to query the status of the application:

   kubectl get deployment my-nginx

   Expected output:

   NAME       READY   UP-TO-DATE   AVAILABLE   AGE
   my-nginx   2/2     2            2           50s

Console operation guide

1. Log on to the ACK console. In the left-side navigation pane, click Clusters.

2. On the Clusters page, find the cluster that you want to manage and click its name. In the left-side pane, choose Network > Services.

3. On the Services page, click Create, and set the parameters in the Create Service dialog box.

   Configuration item	Description	Example
   Name	The name of the Service.	my-nginx-svc
   Service Type	Specify Service Type. You can create the following types of Services to handle access from different types of sources: Cluster IP A ClusterIP Service. This type of Service is used for communication within the cluster. Only ClusterIP Services can discover and communicate with each other. If you select Headless Service, you can interact with other service discovery mechanisms without the need to rely on the ClusterIP-based service discovery and load balancing features provided by Kubernetes by default. SLB. Note The new page for creating Services is in canary release. To use the new version, submit a ticket. SLB allows you to create LoadBalancer Services to expose applications in a cluster by using CLB instances or NLB instances. Compared with NodePort Services, the availability and performance of applications exposed by using LoadBalancer Services are greatly improved. Supported SLB instances: CLB: For more information, see CLB. NLB: For more information, see NLB. Node Port A NodePort Service. External users can access this type of Services by using the IP address and specified port of a node. You can connect to a NodePort Service through <NodeIP>:<NodePort>. However, you must manually configure load balancing.	Select SLB. Click Use Existing Resource and select a CLB instance from the drop-down list. The CLB instance in this example is newly created. You must configure listeners for the CLB instance. Therefore, select Overwrite Existing Listeners.
   External Traffic Policy	The External Traffic Policy parameter is available only if you set the Service Type parameter to Node Port or Server Load Balancer. For more information about external traffic policies, see the Differences between external traffic policies section of the "Getting started" topic. Valid values: Local: routs traffic only to the pods of the current node. Cluster: routes traffic to pods on other nodes in the cluster.	Local
   Backend	The backend application that you want to associate with the Service. If you do not select a backend application, no Endpoint objects are created. For more information, see Services-without-selectors.	Name: app Value: my-nginx
   Port Mapping	The Service port and container port. The Service port corresponds to the port field in the YAML file and the container port corresponds to the targetPort field in the YAML file. The container port must be the same as the port that is exposed in the backend pod.	80
   Annotations	Add an annotation to the Service to modify the configuration of the SLB instance. For more information, see Add annotations to the YAML file of a Service to configure CLB instances and Configure NLB instances by using annotations. Important Do not reuse the SLB instance of the API server in the cluster. Otherwise, cluster access failures may occur.	In this example, two annotations are added to specify the pay-by-bandwidth billing method and set the maximum bandwidth to 2 Mbit/s to limit the amount of traffic that flows through the Service. Example: service.beta.kubernetes.io/alibaba-cloud-loadbalancer-charge-type:paybybandwidth service.beta.kubernetes.io/alibaba-cloud-loadbalancer-bandwidth:2
   Label	The label to be added to the Service, which identifies the Service.

   After you configure the parameters, click OK.

4. On the Services page, click the Service you created to go to the Service details page. In the Basic Information section, click 39.106.XX.XX:80 on the right side of External IP to access the application.

kubectl operation guide

1. Use the following YAML content of the sample service to create a file named my-nginx-svc.yaml.

   Modify the selector to match the value of matchLabels in the sample application file my-nginx.yaml (in this example, app: nginx), to associate the service with the backend application.

   apiVersion: v1
   kind: Service
   metadata:
     labels:
       app: nginx
     name: my-nginx-svc
     namespace: default
   spec:
     ports:
     - port: 80
       protocol: TCP
       targetPort: 80
     selector:
       app: nginx
     type: LoadBalancer

2. Run the following command to create a Service named my-nginx-svc and use the Service to expose the application:

   kubectl apply -f my-nginx-svc.yaml

3. Run the following command to confirm that the LoadBalancer Service is created:

   kubectl get svc my-nginx-svc

   Expected output:

   NAME           TYPE           CLUSTER-IP    EXTERNAL-IP      PORT(S)        AGE
   my-nginx-svc   LoadBalancer   172.21.5.82   39.106.XX.XX     80:30471/TCP   5m

4. Run the following command to access the application:

   curl <YOUR-External-IP> # Replace <YOUR-External-IP> with the EXTERNAL-IP address obtained above.

   Expected output:

   <!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>