Configuring the Priorities of Forwarding Rules for LoadBalancer Ingresses

Prerequisites

• A CCE standard or Turbo cluster is available, and the cluster version meets the following requirements:
  • v1.23: v1.23.15-r0 or later
  • v1.25: v1.25.10-r0 or later
  • v1.27: v1.27.7-r0 or later
  • v1.28: v1.28.5-r0 or later
  • v1.29: v1.29.1-r10 or later
  • Other clusters of later versions
• An available workload has been deployed in the cluster for external access. If no workload is available, deploy a workload by referring to Creating a Deployment, Creating a StatefulSet, or Creating a DaemonSet.
• A Service for external access has been configured for the workload. Services Supported by LoadBalancer Ingresses lists the Service types supported by LoadBalancer ingresses.

Notes and Constraints

• This feature is only available when dedicated load balancers are used.

Using kubectl

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

   vi ingress-test.yaml

   The following shows an example configuration using an existing load balancer:

   apiVersion: networking.k8s.io/v1
   kind: Ingress
   metadata:
     name: test
     namespace: default
     annotations:
       kubernetes.io/elb.port: '88'    # The port on the interconnected load balancer
       kubernetes.io/elb.id: 2c623150-17bf-45f1-ae6f-384b036f547e    # The ID of an existing load balancer
       kubernetes.io/elb.class: performance    # The load balancer type, which can only be performance
       kubernetes.io/elb.ingress-order: '1'    # The priority of forwarding rules across different ingresses
       kubernetes.io/elb.rule-priority-enabled: 'true'   # The forwarding rules of an ingress are prioritized based on the forwarding rule sequence in paths.
   spec:
     rules:
       - host: ''
         http:
           paths:
             - path: /test1  # Define a forwarding rule.
               backend:  # The backend Service associated with the rule. The value provided is only an example and can be modified as needed.
                 service:
                   name: test1
                   port:
                     number: 8081
               property:
                 ingress.beta.kubernetes.io/url-match-mode: STARTS_WITH
               pathType: ImplementationSpecific
             - path: /test2  # Define a forwarding rule.
               backend:  # The backend Service associated with the rule. The value provided is only an example and can be modified as needed.
                 service:
                   name: test2
                   port:
                     number: 8081
               property:
                 ingress.beta.kubernetes.io/url-match-mode: STARTS_WITH
               pathType: ImplementationSpecific
     ingressClassName: cce

   Table 1 Annotations for configuring the priorities of forwarding rules

   Parameter	Type	Description
   kubernetes.io/elb.ingress-order	String	The sequence of forwarding rules across different ingresses. The value ranges from 1 to 1000. A smaller value indicates a higher priority. The priority of a forwarding rule must be unique under the same load balancer listener. This parameter is available only for dedicated load balancers. NOTE: When this annotation is configured, the kubernetes.io/elb.rule-priority-enabled annotation is enabled by default. The forwarding rules of each ingress will be sorted. The priority specified in the kubernetes.io/elb.ingress-order annotation does not directly equate to the priority of the load balancer's forwarding policy. This annotation can be used to prioritize different ingresses. Ingresses with this annotation have a higher priority than those without the annotation. If multiple ingresses are labeled with this annotation, they are prioritized by the annotation value. A smaller value indicates a higher priority. For more details, see Examples for Setting the Priorities of Forwarding Rules.
   kubernetes.io/elb.rule-priority-enabled	String	This parameter can only be set to true, indicating to sort the forwarding rules of an ingress. The forwarding rules are prioritized based on the order they were added during ingress creation. A higher-listed rule indicates a higher priority. If this parameter is not configured, the default sorting of the forwarding rules on the load balancer will be used. After this parameter is enabled, it cannot be disabled. This parameter is available only for dedicated load balancers.

3. Create an ingress.

   kubectl create -f ingress-test.yaml

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

   ingress/ingress-test created

4. Check the created ingress.

   kubectl get ingress

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

   NAME          CLASS    HOSTS     ADDRESS          PORTS   AGE
   ingress-test  cce      *         121.**.**.**     88      10s

Examples for Setting the Priorities of Forwarding Rules

Assume the following configurations: The kubernetes.io/elb.ingress-order value of ingress A (ingress-a) is set to 1, and this ingress has forwarding rules A and B. The kubernetes.io/elb.ingress-order value of ingress B (ingress-b) is set to 2, and this ingress has forwarding rules C and D.

The following table lists the sorting order of the load balancer's forwarding policies when ingresses A and B access the same load balancer port.

Priority	Forwarding Rule	Ingress
1	A	ingress-a
2	B	ingress-a
3	C	ingress-b
4	D	ingress-b

Figure 2 Example 1 of the sorting order of the load balancer's forwarding policies

If you add rule E to ingress-b and list the rule ahead of rules C and D, modify the YAML configuration for ingress-b as follows:

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: ingress-b
  namespace: default
  annotations:
    kubernetes.io/elb.port: '88'    # The port on the interconnected load balancer
    kubernetes.io/elb.id: f7fb2aa8-34af-48fb-b451-16e8f675ff45   # The ID of the existing load balancer
    kubernetes.io/elb.class: performance    # The type of the existing load balancer, which can only be performance
    kubernetes.io/elb.ingress-order: '2'    # The priority of forwarding rules across different ingresses
    kubernetes.io/elb.rule-priority-enabled: 'true'   # The forwarding rules of an ingress are prioritized based on the forwarding rule sequence in paths.
spec:
  rules:
    - host: ''
      http:
        paths:
          - path: /E  # Define forwarding rule E.
            backend:  # The backend Service associated with the rule. The value provided is only an example and can be modified as needed.
              service:
                name: nginx
                port:
                  number: 80
            property:
              ingress.beta.kubernetes.io/url-match-mode: STARTS_WITH
            pathType: ImplementationSpecific
          - path: /C  # Define forwarding rule C.
            backend:  # The backend Service associated with the rule. The value provided is only an example and can be modified as needed.
              service:
                name: nginx
                port:
                  number: 80
            property:
              ingress.beta.kubernetes.io/url-match-mode: STARTS_WITH
            pathType: ImplementationSpecific
          - path: /D  # Define forwarding rule D.
            backend:  # The backend Service associated with the rule. The value provided is only an example and can be modified as needed.
              service:
                name: nginx
                port:
                  number: 80
            property:
              ingress.beta.kubernetes.io/url-match-mode: STARTS_WITH
            pathType: ImplementationSpecific
  ingressClassName: cce

The following table lists the sorting order of the load balancer's forwarding rules.

Priority	Forwarding Rule	Ingress
1	A	ingress-a
2	B	ingress-a
3	E	ingress-b
4	C	ingress-b
5	D	ingress-b

Figure 3 Example 2 of the sorting order of the load balancer's forwarding policies