Updating to the `2025-04-08` version (SNI hostname support for application load balancers)

As described in the VPC API reference versioning policy, most changes to the VPC APIs are fully backward compatible and are made available to all clients, regardless of the API version the client requests. However, the 2025-04-08 release of the VPC API necessitated incompatible changes in support of creating a listener policy for application load balancers (ALBs).

Before you adopt the release version 2025-04-08 or later, review the changes described in this migration guidance that might require you to update your client.

Changed application load balancer policy properties

The following application load balancer listener policy property has changed for API requests that use a version query parameter of 2024-04-08 or later.

When creating an application load balancer policy (POST /load_balancers/{load_balancer_id}/listeners/{listener_id}/policies):

Old and new properties when creating an ALB listener policy.
Old property	New property
`action.forward`	`action.forward_to_pool`

When retrieving an ALB listener policy (GET /load_balancers/{load_balancer_id}/listeners/{listener_id}/policies/{id}):

Old and new properties when retrieving an ALB listener policy.
Old property	New property
`action.forward`	`action.forward_to_pool`

When listing policies for a load balancer listener (GET /load_balancers/{load_balancer_id}/listeners/{listener_id}/policies):

Old and new properties when listing an ALB listener policies.
Old property	New property
`action.forward`	`action.forward_to_pool`

Action needed

Before you specify the version query parameter of 2025-04-08 or later, follow these actions to avoid regressions in client functionality.

If your clients continue to specify version 2025-04-07 or earlier, no changes are required.

Client migration

Before you migrate a client to API version 2025-04-08 or later, review your code that uses the following methods:

POST /load_balancers/{load_balancer_id}/listeners/{listener_id}/policies
GET /load_balancers/{load_balancer_id}/listeners/{listener_id}/policies/{id}
GET /load_balancers/{load_balancer_id}/listeners/{listener_id}/policies

Review the changes that were announced in the API change log, and verify that your code adopts these changes in a manner that is appropriate for your programming language.

Example

Creating an ALB listener policy

The following example uses API version 2025-04-07 or earlier to create an application load balancer listener policy with the action forward.

curl -X POST "$vpc_api_endpoint/v1/load_balancers/$load_balancer_id/listeners/$listener_id/policies?version=2025-04-07&generation=2"
-H "Authorization: $iam_token"
 -d '{
      "action": "forward",
      "name": "older-version-2025-04-07",
      "priority": 3,
      "rules": [
        {
          "condition": "contains",
          "type": "hostname",
          "value": "www.example.com"
        }
      ],
      "target": {
        "id": "$target_pool_id"
      }
  }'

The following example uses API version 2025-04-08 or later to create an application load balancer listener policy with the action forward_to_pool.