Configuring an HTTP/HTTPS Header for a LoadBalancer Service

Prerequisites

• A Kubernetes cluster is available and the cluster version meets the requirements in Table 1.

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

Creating a LoadBalancer Service and Configuring an HTTP/HTTPS Header

Using the CCE Console

1. Log in to the CCE console and click the cluster name to access the cluster console.
2. In the navigation pane, choose Services & Ingresses. In the upper right corner, click Create Service.
3. Configure Service parameters. In this example, only mandatory parameters are listed. For details about how to configure other parameters, see Using the CCE Console.
   • Service Name: Enter a 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, and the type of the load balancer must be Application (HTTP/HTTPS) or Network (TCP/UDP/TLS) & Application (HTTP/HTTPS). Otherwise, HTTP or HTTPS cannot be enabled on the listener port.
     • This section uses an existing load balancer as an example. For details about the parameters for automatically creating a load balancer, see Table 1.
   • Port
     • Protocol: Select TCP. If you select UDP, HTTP and HTTPS will be unavailable.
     • Service Port: the port used by the Service. The port ranges from 1 to 65535.
     • Container Port: the port that the workload listens on. For example, Nginx uses port 80 by default.
     • Frontend Protocol: In this example, select HTTP or HTTPS for the Service.
   • Listener
     • Advanced Options: Select a proper option.

       Configuration	Description	Constraint
       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 parameter is available only after HTTP/HTTPS is enabled on the listener port of a dedicated load balancer.
       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 parameter is available only after HTTP/HTTPS is enabled on the listener port of a dedicated load balancer.
       Rewrite X-Forwarded-Host	If this function is enabled, X-Forwarded-Host will be rewritten using the Host field in the client request header and transferred to backend servers.	This parameter is available only after HTTP/HTTPS is enabled on the listener port of a dedicated load balancer.
       Rewrite X-Real-IP	If this function is enabled, the source IP address of the client will be rewritten into the X-Real-IP header and transferred to backend servers.	This parameter is available only after HTTP/HTTPS is enabled on the listener port of a dedicated load balancer.

   Figure 1 Configuring HTTP/HTTPS headers
   

4. Click OK.

Using kubectl

apiVersion: v1
kind: Service
metadata:
  name: test
  labels:
    app: nginx
  namespace: default
  annotations:
    kubernetes.io/elb.class: performance                              # Load balancer type, which can only be performance (dedicated load balancer)
    kubernetes.io/elb.id: 35cb350b-23e6-4551-ac77-10d5298f5204        # ID of an existing load balancer
    kubernetes.io/elb.protocol-port: http:80                          # The HTTP port 80 is used.
    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.
    kubernetes.io/elb.x-real-ip: 'true'                              # Rewrite X-Real-IP.
spec:
  selector:
    app: nginx
  externalTrafficPolicy: Cluster
  ports:
    - name: cce-service-0
      targetPort: 80
      nodePort: 0
      port: 80
      protocol: TCP
  type: LoadBalancer
  loadBalancerIP: **.**.**.**    # IP address of the load balancer

Verifying Configuration

1. Log in to the CCE console and click the cluster name to access the cluster console.
2. In the navigation pane, choose Services & Ingresses. Locate the row that contains the created Service and click the load balancer name to go to the ELB console.
3. Switch to the Listeners tab, click the listener name of the created port, and check whether options are enabled.