AWS ECS – Using Boto3 to update a task definition

Using boto3, we can create a new task definition:

client = boto3.client('ecs')
client.register_task_definition(...)

How do we update an existing task definition? Is it just another call with changes and the same family name?

Answer

update an existing task definition

You can’t do this. You have to create a new revision of an existing task definition. Then you will also have to update your ECS service to use the new task revision. Running register_task_definition again should automatically create new revision for you.