Re-use existing task def with latest version

[vivekyad4v]

We are managing our task def in Terraform. We do not want ecs-deploy to create/register a new taskdef. Instead we just want it to update the service with latest version of existing taskdef.

Is there a way?

Used below command but no luck since it worked as expected -

ecs deploy my-cluster my-service --task my-task --timeout 420

[fabfuel]

Hi @vivekyad4v

was there something wrong with the end-result after you ran the mentioned command, except for there was a new revision created?

The current mechanism is, that ecs-deploy creates a new task-definition (with optional adjustments) and updates the services accordingly to use this task-def revision.

Do I understand correctly, that you want ecs-deploy to identify the newest revision of a task family and update the service with this revision?

This is your desired workflow, right?

1. run terraform to create a new task definition (revision)
2. run ecs-deploy "ecs use-newest-revision my-cluster my-service"

Best Fabian

[fabfuel]

Not directly related, but as you use Terraform, this might be useful: https://twitter.com/fabfuel/status/1178249588353982464?s=20

[vivekyad4v]

Yes, as you suggested, below is the desired workflow -

1. run terraform to create a new task definition (revision)
2. run ecs-deploy "ecs use-newest-revision my-cluster my-service"

Why we need this is because we manage all SSM paramters, Taskdefs, Services, CICD etc in Terraform itself. Post a change, the latest taskdef ARN is passed to AWS codebuild project as a parameter which in turn is used to deploy the ECS service. The problem happens when ecs-deploy creates the new taskdef which Terraform is unaware of and creates a conflict. We have a workaround as to let Terraform use the latest taskdef by defining a data source. However, it would be great if we can get this feature in this super awesome tool. I am pretty sure there can be similar use cases where people just want to deploy the lastest taskdef since it's managed by some other tool.

This would be super cool - $ ecs use-newest-revision my-cluster my-service

[oliver-schoenherr]

@vivekyad4v the documentation already mentioned a solution:

https://github.com/fabfuel/ecs-deploy#deploy-a-custom-task-definition

Deploy a custom task definition Or just a task family name. It this case, the most recent revision is used: $ ecs deploy my-cluster my-service --task my-task

[Sytten]

This is still an issue, read just below:

ecs will still create a new task definition, which then is used in the service.

This is problematic for my setup. I would just add an optional parameter to disable that feature and just use the given task definition.

[nitrocode]

If you just want to update the service with the current task definition, couldn't you simply use the awscli?

aws ecs \
  update-service \
  --cluster <name> \
  --service <name> \
  --force-new-deployment

[nitrocode]

@Sytten could you expand on your downvote? Why would that not be a viable option ?

[Sytten]

I mean it's not bad advice per se but it is not what the issue is about. It is about updating a service to the latest task definition version without creating a new one. So say I have a task definition my-task where the version 0 is assigned to the service, then I create a new version in terraform or somewhere else (version 1). If I do a --force-new-deployment it just creates new pods with the same version 0, where what we want is that the service be updated to version 1 without this tool creating a version 2 :)

[fabfuel]

Hi folks,

could you please check, if this solves your issue? Instead of --force-new-deployment you can provide the task definition family (or name) without a revision, ECS will then pick the newest revision automatically:

aws ecs \
  update-service \
  --cluster <name> \
  --service <name> \
  --task-definition <task definition family>

For example:

aws ecs update-service --cluster foobar --service nginx --task-definition nginx

From the AWS CLI help:

--task-definition (string) The family and revision (family:revision ) or full ARN of the task definition to run in your service. If a revision is not specified, the latest ACTIVE revision is used.

Best Fabian