Configuring an HTTP/HTTPS Header for a LoadBalancer Ingress

HTTP headers are a list of strings sent and received by both the client and server on every HTTP request and response. This section describes HTTP headers supported by HTTP and HTTP listeners.

HTTP/HTTPS headers rely on ELB. Before using HTTP/HTTPS headers in a Service, check whether HTTP/HTTPS headers are supported in the current region. For details, see HTTP/HTTPS Headers.
After HTTP or HTTPS is configured, if you delete the HTTP or HTTPS configuration on the CCE console or delete the target annotation from the YAML file, the configuration on the ELB will be retained.

**Table 1** Headers
Header	Feature	Description
X-Forwarded-Port	Transfer Listener Port Number	If this option is enabled, the port number used by the listener will be transmitted to backend servers through the X-Forwarded-Port header.
X-Forwarded-For-Port	Transfer Port Number in the Request	If this option is enabled, the port number used by the client will be transmitted to backend servers through the X-Forwarded-For-Port header.
X-Forwarded-Host	Rewrite X-Forwarded-Host	If this function is enabled, X-Forwarded-Host will be rewritten using the Host field in the client request body and transferred to backend servers.

Prerequisites

A Kubernetes cluster is available and the cluster version meets the following requirements:
- v1.23: v1.23.13-r0 or later
- v1.25: v1.25.8-r0 or later
- v1.27: v1.27.5-r0 or later
- v1.28: v1.28.3-r0 or later
- Other clusters of later versions

To create a cluster using commands, ensure kubectl is used. For details, see Connecting to a Cluster Using kubectl.

Using the CCE Console

Log in to the CCE console and click the cluster name to access the cluster console.
In the navigation pane, choose Services & Ingresses. Click the Ingresses tab and click Create Ingress in the upper right corner.

Configure ingress parameters. In this example, only mandatory parameters are listed. For details about how to configure other parameters, see Creating a LoadBalancer Ingress on the Console.

Name: can be the same as the workload name.
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 load balancers.

Listener

External Protocol: HTTP and HTTPS are available. This section uses HTTP as an example.
External Port: port number that is open to the ELB service address. The port number is configurable.

Advanced Options

Configuration	Description	Restrictions
Transfer Listener Port Number	If this function is enabled, the listening port on the load balancer can be transferred to backend servers through the HTTP header of the packet.	This function is available only for dedicated load balancers.
Transfer Port Number in the Request	If this function is enabled, the source port of the client can be transferred to backend servers through the HTTP header of the packet.	This function is available only for dedicated load balancers.
Rewrite X-Forwarded-Host	If this function is enabled, X-Forwarded-Host will be rewritten using the Host field in the client request body and transferred to backend servers.	This function is available only for dedicated load balancers.

Figure 1 Configuring HTTP/HTTPS headers
Click to enlarge

Forwarding Policy: Specify a domain name matching rule and the target Service to be accessed. When the access address of a request matches the forwarding policy (a forwarding policy consists of a domain name and URL, for example, 10.117.117.117:80/helloworld), the request will be forwarded to the target Service for processing.

Click OK.

Using kubectl

The following uses an existing created load balancer as an example. The YAML file is configured as follows:

apiVersion: networking.k8s.io/v1
kind: Ingress 
metadata: 
  name: ingress-test
  annotations: 
    kubernetes.io/elb.id: <your_elb_id>                 # Replace it with the ID of your existing load balancer.
    kubernetes.io/elb.class: performance                # Load balancer type
    kubernetes.io/elb.port: '80'
    kubernetes.io/elb.x-forwarded-port: 'true'         # Obtain the listener port number.
    kubernetes.io/elb.x-forwarded-for-port: 'true'     # Obtain the client port number for requests.
    kubernetes.io/elb.x-forwarded-host: 'true'         # Rewrite X-Forwarded-Host.
spec:
  rules: 
  - host: ''
    http: 
      paths: 
      - path: '/'
        backend: 
          service:
            name: <your_service_name>  # Replace it with the name of your target Service.
            port: 
              number: 8080             # Replace 8080 with the port number of your target Service.
        property:
          ingress.beta.kubernetes.io/url-match-mode: STARTS_WITH
        pathType: ImplementationSpecific
  ingressClassName: cce

**Table 2** Key parameters
Parameter	Type	Description
kubernetes.io/elb.x-forwarded-port	String	A load balancer can obtain the port number of a listener using X-Forwarded-Port and transmit the port number to the packets of the backend server. true: Enable the function of obtaining a listener port number. false: Disable the function of obtaining a listener port number.
kubernetes.io/elb.x-forwarded-for-port	String	A load balancer can obtain a client port number for requests using X-Forwarded-For-Port and transmit the port number to the packets of the backend server. true: Enable the function of obtaining a client port number for requests. false: Disable the function of obtaining a client port number for requests.
kubernetes.io/elb.x-forwarded-host	String	true: Enable the function of rewriting X-Forwarded-Host. Then, the X-Forwarded-Host header will be rewritten using the Host header of the client request and transmitted to backend servers. false: Disable the function of rewriting X-Forwarded-Host. Then, the X-Forwarded-Host header of the client will be transmitted to backend servers.