Container Service for Kubernetes:Use an existing Server Load Balancer 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 your cluster and click its name. In the left-side pane, choose Workloads > Deployments.

3. On the Deployments page, click Create from Image and configure the Deployment:

   1. On the Basic Information page, set Name to my-nginx and click Next.

   2. On the Container page, configure the image and port:

      Parameter	Value
      Image Name	Click Select images. On the Artifact Center tab, search for nginx and select openanolis/nginx. Click Select Image Tag, set a tag, and click OK.
      Port	Name: nginx, Container Port: 80

   3. On the Advanced page, keep the defaults and click Create.

Use kubectl

1. Create a file named my-nginx.yaml with the following content:

   apiVersion: apps/v1
   kind: Deployment
   metadata:
     name: my-nginx        # Deployment name
     labels:
       app: nginx
   spec:
     replicas: 2           # Number of pod replicas
     selector:
       matchLabels:
         app: nginx        # Must match the selector in the Service
     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

2. Deploy the application:

   kubectl apply -f my-nginx.yaml

3. Verify the Deployment is ready:

   kubectl get deployment my-nginx

   Expected output:

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

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 your cluster and click its name. In the left-side pane, choose Network > Services.

3. On the Services page, click Create. In the Create Service dialog box, configure the following parameters:

   Parameter	Description	Example
   Name	Name of the Service	my-nginx-svc
   Service Type	Select SLB, set SLB Type to CLB, and choose Use Existing Resource. Select a CLB instance from the drop-down list. If the instance has no listeners configured yet, select Overwrite Existing Listeners.	SLB > CLB > Use Existing Resource
   External Traffic Policy	Local routes traffic only to pods on the current node. Cluster routes traffic to pods across all nodes.	Local
   Backend	The application to associate with the Service	Name: app, Value: nginx
   Port Mapping	Maps the Service port to the container port	Service port: 80, Container port: 80, Protocol: TCP
   Annotations	Add annotations to configure the SLB instance. See Use annotations to configure CLB instances and Use annotations to configure NLB instances.	N/A

4. Click OK. After the Service is created, click its name to open the details page. In the Overview section, click the External IP (for example, 39.106.XX.XX:80) to verify the application is accessible.

   

Use kubectl

1. Create a file named my-nginx-svc.yaml with the following content:

   Field	Description
   metadata.annotations	alibaba-cloud-loadbalancer-id specifies the existing SLB instance ID. alibaba-cloud-loadbalancer-force-override-listeners: 'true' lets ACK create and manage listeners on the instance. Omit this annotation to preserve the existing listener configuration.
   spec.selector	Selects the pods to receive traffic. Must match the matchLabels in the Deployment (app: nginx).
   spec.ports.port	The Service port exposed on the cluster IP. Access the Service within the cluster at clusterIP:port.
   spec.ports.targetPort	The port on the backend pod. kube-proxy forwards traffic from port to targetPort on each pod.

   apiVersion: v1
   kind: Service
   metadata:
     annotations:
       service.beta.kubernetes.io/alibaba-cloud-loadbalancer-id: ${YOUR_LB_ID}                      # Replace with your SLB instance ID
       service.beta.kubernetes.io/alibaba-cloud-loadbalancer-force-override-listeners: 'true'       # Set to true for a new instance with no listeners configured
     labels:
       app: nginx
     name: my-nginx-svc
     namespace: default
   spec:
     ports:
     - port: 80
       protocol: TCP
       targetPort: 80
     selector:
       app: nginx            # Must match the labels on the backend pods
     type: LoadBalancer

   Key fields:

2. Apply the Service:

   kubectl apply -f my-nginx-svc.yaml

3. Confirm the Service is running and has an external IP:

   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. Access the application:

   curl <YOUR-EXTERNAL-IP>    # Replace with the external IP from the previous step

   Expected output:

   <!DOCTYPE html>
   <html>
   <head>
   <title>Welcome to nginx!</title>
   ...
   </html>

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 your cluster and click its name. In the left-side pane, choose Network > Services.

3. On the Services page, click a Service to view its details, or click Update or Delete in the Actions column.

Use kubectl

Update a Service

kubectl edit service my-nginx-svc

Alternatively, edit my-nginx-svc.yaml and reapply:

kubectl apply -f my-nginx-svc.yaml

View a Service

kubectl get service my-nginx-svc

Expected output:

NAME           TYPE           CLUSTER-IP     EXTERNAL-IP      PORT(S)        AGE
my-nginx-svc   LoadBalancer   172.21.XX.XX   192.168.XX.XX    80:31599/TCP   5m

Delete a Service

kubectl delete service my-nginx-svc