cloudformation ecs force new deployement

What is the equivalent of --force-new-deployment flag in cloudformation ? (aws ecs update-service --cluster --service --force-new-deployment)

In my cloudformation template, my docker image tag is latest. However I want to be able to force the redeployment if I replay the stack.

Thanks you

Solution

Think of CloudFormation as just a provisioning service or an orchestrator.

Specifying an Image as repository-url/image:tag will definitely fetch the specified image with specific tag from your repo but only upon a stack operation. Once a stack operation is finished, any changes to service will be depending on the next stack operation.

What you can do here is either having either

Cloudwatch Event based rule targeting a Lambda Function whenever there is an image upload to ECR.
Or in case of using some other repo than ECR, have a hook configured in a way that will invoke update-service --cluster --service --force-new-deployment ... command whenever there is a new image upload.

Considerations:

This can lead your stack being in DRIFTED status.
Just make sure to keep your stack's Image property's value in sync with the latest one running within service, whenever you plan to update the stack.