Hello Folks,
Please take time to read announcement from AWS below regarding timeline for new ARN format for ECS resources.

---
Hello,

We are contacting you regarding the change in the process for opting in to the Amazon ECS long Amazon Resource Name (ARN) format for your AWS account [1]. Amazon ECS resources are assigned a unique ARN and Amazon ECS added support for a new longer ARN format in November, 2018 which introduced the name of the cluster into the ARN. Opting in to this longer ARN format is required in order to take advantage of tagging support for your Amazon ECS resources. If you have already opted in to the long ARN format then no action is required by you and this communication is purely informational. You can verify your account opt-in status in account settings [1].

In order to ensure tagging is generally available to our customers, we are introducing a timeline to migrate customer accounts to this new ARN format. This timeline will see new accounts opted in to the long ARN format by default, followed later by all accounts to be transitioned to the longer ARN format. The new longer ARN format effects the container instance, service and task resource ARNs [2]. The ARN for existing resources WILL NOT be changed.

You are able to manage your account opt in status up to the end of the migration process using the Amazon ECS console or through the CLI [3]. Please refer to the “ARN and resource ID format timeline” section of the Amazon ECS account settings documentation for more details [4].

If you have any questions please contact AWS support [5].

[1] https://docs.aws.amazon.com/Am azonECS/latest/developerguide/ecs-account-settings.html
[2] https://docs.aws.amazon.com/Am azonECS/latest/developerguide/ecs-account-settings.html#ecs-resource-ids
[3] https://docs.aws.amazon.com/Am azonECS/latest/developerguide/ecs-modifying-longer-id-settings.html
[4] https://docs.aws.amazon.com/Am azonECS/latest/developerguide/ecs-account-settings.html#ecs-resource-arn-timeline
[5] https://aws.amazon.com/support

Sincerely,
Amazon Web Services

---

From now until September 30, 2020 – The ability to opt in to and opt out of the new Amazon Resource Name (ARN) and resource IDs is provided on a per-Region basis. Any new accounts created are opted out by default.
October 1, 2020 - March 31, 2021 – All new accounts are opted in to the new format by default. Any existing accounts that have not explicitly opted out of the new format are also opted in. The ability to opt in and opt out continues to be available on a per-Region basis.
April 1, 2021 – All accounts will be opted in by default. All new resources created will receive the new format. The ability to opt out will no longer be available.

[psa][ACTION MAY BE REQUIRED] Migration timeline for new ARN format for Amazon ECS resource

Important Dates