Updated on 2024-09-02 GMT+08:00

Configuring URL Redirection for a LoadBalancer Ingress

Ingress can redirect specific access requests to a specified path. The following is an example of YAML file for configuring an ingress redirection rule. In this example, the request for accessing example.com is redirected to example.com/testa and status code 301 is returned.

Prerequisites

Notes and Constraints

  • The advanced forwarding policy of LoadBalancer ingresses is available only to dedicated load balancers.
  • The advanced forwarding policy of LoadBalancer ingresses is available only in clusters of version v1.23.14-r0, v1.25.9-r0, v1.27.6-r0, v1.28.4-r0, or later.

Configuring a Rule for Redirecting an Ingress to a URL

You can configure a rule for redirecting an ingress to a URL using either the CCE console or kubectl.

  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 Ingresses tab, and click Create Ingress in the upper right corner.
  3. Configure ingress parameters.

    This example explains only key parameters for configuring URL redirection. You can configure other parameters as required. For details, see Creating a LoadBalancer Ingress on the Console.

    Table 1 Key parameters

    Parameter

    Description

    Example

    Name

    Enter an ingress name.

    ingress-test

    Load Balancer

    Select a load balancer to be associated with the ingress or automatically create a load balancer. In this example, only dedicated load balancers are supported.

    Dedicated

    Listener

    • External Protocol: HTTP and HTTPS are available.
    • External Port: specifies the port of the load balancer listener.
    • External Protocol: HTTP
    • External Port: 80

    Forwarding Policy

    • Domain Name: Enter actual domain name to be accessed. If it is left blank, the ingress can be accessed through the IP address. Ensure that the domain name has been registered and licensed. Once a forwarding policy is configured with a domain name specified, you must use the domain name for access.
    • Path Matching Rule: Select Prefix match, Exact match, or RegEx match.
    • Path: Enter the path provided by a backend application for external access. The path added must be valid in the backend application, or the forwarding cannot take effect.
    • Destination Service: Select an existing Service or create a Service. Any Services that do not match the search criteria will be filtered out automatically.
    • Destination Service Port: Select the access port of the destination Service.
    • Actions
      • Operation: Select Redirect to URL. When an access request meets the forwarding policy, the request will be redirected to a specified URL, and a specific status code will be returned.
      • URL: A URL starting with http:// or https:// is valid.
        NOTE:

        HTTP routes can be redirected to HTTP or HTTPS routes. HTTPS routes can be redirected only to HTTPS routes.

      • StatusCode: The return code can be 301, 302, 303, 307, or 308.
    • Domain Name: example.com
    • Path Matching Rule: Prefix match
    • Path: /
    • Destination Service: nginx
    • Destination Service Port: 80
    • Actions:
      • Operation: Redirect to URL
      • URL: https://example.com/testa
      • StatusCode: 301
    Figure 1 Configuring a rule for redirecting an ingress to a URL

  4. Click OK.

An ingress can be redirected to a URL using annotations. Example:

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

    vi ingress-test.yaml

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

    apiVersion: networking.k8s.io/v1
    kind: Ingress
    metadata:
      name: test-redirect-url
      namespace: default
      annotations:
        kubernetes.io/elb.id: df76342f-e898-402a-bac8-bde5bf974da8
        kubernetes.io/elb.class: performance
        kubernetes.io/elb.port: '80'
        kubernetes.io/elb.redirect-url: https://example.com/testa        # Information about the redirection to a URL
        kubernetes.io/elb.redirect-url-code: '301'     # Code returned after the ingress is redirected to a URL
    spec:
      rules:
        - host: "example.com"
          http:
            paths:
              - path: /
                backend:
                  service:
                    name: test-service
                    port:
                      number: 80
                property:
                  ingress.beta.kubernetes.io/url-match-mode: STARTS_WITH
                pathType: ImplementationSpecific
      ingressClassName: cce
    Table 2 Key parameters

    Parameter

    Mandatory

    Type

    Description

    kubernetes.io/elb.redirect-url

    Yes

    String

    URL for redirection

    Format: A valid URL must start with http:// or https://, for example, https://example.com/.

    Parameter: This configuration takes effect on all forwarding rules of a single ingress. After the configuration is deleted, the target URL redirection rule will be automatically cleared.

    Either this annotation or the annotation of a grayscale release can be configured.

    kubernetes.io/elb.redirect-url-code

    No

    String

    Code returned after an ingress is redirected to a URL.

    Format: The return code can be 301, 302, 303, 307, or 308.

    Parameter: The default value is 301.

  3. Create an ingress.

    kubectl create -f ingress-test.yaml

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

    ingress/test-redirect-url 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
    test-redirect-url  cce      example.com   121.**.**.**     80      10s

  5. Use curl to verify the redirection, where ${ELB_IP} is the IP address accessed by the target ingress.

    curl -I -H "Host:example.com" ${ELB_IP}

    The access path will be redirected to example.com/testa.

    HTTP/1.1 301 Moved Permanently
    Date: Thu, 07 Mar 2024 11:04:31 GMT
    Content-Type: text/html
    Content-Length: 134
    Connection: keep-alive
    Location: https://example.com/testa
    Server: elb