Configuring a Blocklist/Trustlist Access Policy for a LoadBalancer Service

When using a LoadBalancer Service, you can configure a trustlist or blocklist to specify the IP addresses that are allowed or denied to access a load balancer listener.

Trustlist: Only the IP addresses in the list can access the listener.
Blocklist: The IP addresses in the list are not allowed to access the listener.

Prerequisites

A Kubernetes cluster is available and the cluster version meets the following requirements:
- v1.23: v1.23.12-r0 or later
- v1.25: v1.25.7-r0 or later
- v1.27: v1.27.4-r0 or later
- v1.28: v1.28.2-r0 or later
- Other clusters of later versions
An IP address group has been created on the ELB console. For details, see Creating an IP Address Group.

Using the CCE Console

Log in to the CCE console and click the cluster name to access the cluster console.
Choose Services & Ingresses in the navigation pane, click the Services tab, and click Create Service in the upper right corner.
Configure Service parameters.
- Service Name: Enter a service name, for example, service-acl.
- Service Type: Select LoadBalancer.
- Service Affinity: Select cluster level or node level as needed. For details about the differences, see externalTrafficPolicy (Service Affinity).
- 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 to be accessed. Only load balancers in the same VPC as the cluster are supported. If no load balancer is available, click Create Load Balancer to create one on the ELB console. Alternatively, select Auto create to create a load balancer. For details about parameter settings, see Table 1.
- Health Check: defaults to Global health check. You can configure this parameter as needed.
- Ports
  - Protocol: protocol used by the Service.
  - Service Port: port used by the Service. The port number ranges from 1 to 65535.
  - Container Port: listener port of the workload. For example, Nginx uses port 80 by default.
- Access Control
  - Allow all IP addresses: No access control is configured.
  - Trustlist: Only the selected IP address group can access the load balancer.
  - Blocklist: The selected IP address group cannot access the load balancer.
Click OK.

Using kubectl

An example YAML file of a Service created using an existing load balancer is as follows:

apiVersion: v1 
kind: Service 
metadata: 
  name: nginx
  annotations:
    kubernetes.io/elb.id: <your_elb_id>                    # Load balancer ID. Replace it with the actual value.
    kubernetes.io/elb.class: performance                   # Load balancer type
    kubernetes.io/elb.acl-id: <your_acl_id>               # ID of an IP address group for accessing a load balancer
    kubernetes.io/elb.acl-status: 'on'                  # Enable access control.
    kubernetes.io/elb.acl-type: 'white'                   # Trustlist for access control
spec:
  selector: 
     app: nginx
  ports: 
  - name: service0 
    port: 80
    protocol: TCP 
    targetPort: 80
  type: LoadBalancer

**Table 1** Annotations for ELB access control
Parameter	Type	Description
kubernetes.io/elb.acl-id	String	If this parameter is not specified, CCE does not modify access control on the ELB. If this parameter is left empty, all IP addresses are allowed to access the load balancer. If this parameter is set to the IP address group ID of the load balancer, access control is enabled and you need to configure an IP address blocklist or trustlist for the load balancer. Additionally, you need to configure both kubernetes.io/elb.acl-status and kubernetes.io/elb.acl-type. How to obtain: Log in to the console. In the Service List, choose Networking > Elastic Load Balance. On the Network Console, choose Elastic Load Balance > IP Address Groups and copy the ID of the target IP address group. For details, see Creating an IP Address Group.
kubernetes.io/elb.acl-status	String	This parameter is mandatory when you configure an IP address blocklist or trustlist for a load balancer. Options: on: Access control is enabled. off: Access control is disabled.
kubernetes.io/elb.acl-type	String	This parameter is mandatory when you configure an IP address blocklist or trustlist for a load balancer. Options: black: indicates a blocklist. The selected IP address group cannot access the load balancer. white: indicates a trustlist. Only the selected IP address group can access the load balancer.