Configuring a Range of Listening Ports for LoadBalancer Services

Prerequisites

• A Kubernetes cluster is available and the cluster version meets the following requirements:
  • v1.23: v1.23.18-r0 or later
  • v1.25: v1.25.13-r0 or later
  • v1.27: v1.27.10-r0 or later
  • v1.28: v1.28.8-r0 or later
  • v1.29: v1.29.4-r0 or later
  • v1.30: v1.30.1-r0 or later
• To create a cluster using commands, ensure kubectl is used. For details, see Connecting to a Cluster Using kubectl.

Precautions

You can configure a range of listening ports only when a dedicated load balancer is used and the TCP, UDP, or TLS protocol is selected.

Using the CCE Console

1. Log in to the CCE console and click the cluster name to access the cluster console.
2. Choose Services & Ingresses in the navigation pane, click the Services tab, and click Create Service in the upper right corner.
3. Configure Service parameters. In this example, only mandatory parameters are listed. For details about how to configure other parameters, see Using the Console.
   • Service Name: Specify a Service name, which can be the same as the workload name.
   • Service Type: Select LoadBalancer.
   • Selector: Add a label and click Confirm. The Service will use this label to select pods. You can also click Reference Workload Label to use the label of an existing workload. In the dialog box that is displayed, select a workload and click OK.
   • Load Balancer: Select a load balancer type and creation mode.
     • In this example, only dedicated load balancers are supported.
     • This section uses an existing load balancer as an example. For details about the parameters for automatically creating a load balancer, see Table 1.
   • Ports
     • Protocol: Select TCP or UDP.
     • Container Port: listener port of the workload. For example, Nginx uses port 80 by default.
     • Service Port: port used by the Service. In this example, select Listen on ports and configure a port range. All the requests received on the ports within this range will be forwarded to the backend server. Configure the port range from 1 to 65535. You can add a maximum of 10 non-overlapping ranges of listening ports.
     • Frontend Protocol: For a dedicated load balancer, to use TLS, the type of the load balancer must be Network (TCP/UDP/TLS).
   Figure 1 Configuring listening port ranges
   

4. Click OK.

Using kubectl

1. Use kubectl to access the cluster. For details, see Connecting to a Cluster Using kubectl.
2. Create a YAML file named service-test.yaml. The file name can be customized.

   vi service-test.yaml

   An example YAML file of a Service associated with an existing load balancer is as follows:

   apiVersion: v1
   kind: Service
   metadata:
     name: service-test
     labels:
       app: test
       version: v1
     namespace: default
     annotations:
       kubernetes.io/elb.class: performance  # A dedicated load balancer is required.
       kubernetes.io/elb.id: <your_elb_id>  # Replace it with the ID of your existing load balancer.
       kubernetes.io/elb.port-ranges: '{"cce-service-0":["100,200", "300,400"], "cce-service-1":["500,600", "700,800"]}'  # Configure ranges of listening ports.
   spec:
     selector:
       app: test
       version: v1
     externalTrafficPolicy: Cluster
     ports:
       - name: cce-service-0
         targetPort: 80          # Replace it with your container port.
         nodePort: 0
         port: 100       # If a port range is configured for listening, this parameter becomes invalid. However, it still needs to be assigned a unique value. By default, it is set to the starting port number of the range.
         protocol: TCP  
       - name: cce-service-1
         targetPort: 81          # Replace it with your container port.
         nodePort: 0
         port: 500       # If a port range is configured for listening, this parameter becomes invalid. However, it still needs to be assigned a unique value.
         protocol: TCP  
     type: LoadBalancer
     loadBalancerIP: <your_elb_ip>  # Replace it with the private IP address of your existing load balancer.

   Table 1 Parameters for listening to ports within a range

   Parameter	Mandatory	Type	Description
   kubernetes.io/elb.port-ranges	Yes	String	If a dedicated load balancer is used and the TCP, UDP, or TLS protocol is selected, you can create a listener that listens to ports within a certain range from 1 to 65535. You can add a maximum of 10 non-overlapping port ranges for each listener. The parameter value is in the following format, where ports_name and port must be unique: '{"<ports_name_1>":["<port_1>,<port_2>","<port_3>,<port_4>"], "<ports_name_2>":["<port_5>,<port_6>","<port_7>,<port_8>"]}' For example, the port names are cce-service-0 and cce-service-1, and the listener listens to ports 100–200 and 300–400, and 500–600 and 700–800, respectively. '{"cce-service-0":["100,200", "300,400"], "cce-service-1":["500,600", "700,800"]}'

3. Create the Service.

   kubectl create -f service-test.yaml

   If information similar to the following is displayed, the Service has been created:

   service/service-test created