taskDefinition

The family and revision (family:revision) or full ARN of the task definition to run. If a revision isn't specified, the latest ACTIVE revision is used.

When you create a policy for run-task, you can set the resource to be the latest task definition revision, or a specific revision.

The full ARN value must match the value that you specified as the Resource of the principal's permissions policy.

When you specify the policy resource as the latest task definition version (by setting the Resource in the policy to arn:aws:ecs:us-east-1:111122223333:task-definition/TaskFamilyName), then set this value to arn:aws:ecs:us-east-1:111122223333:task-definition/TaskFamilyName.

When you specify the policy resource as a specific task definition version (by setting the Resource in the policy to arn:aws:ecs:us-east-1:111122223333:task-definition/TaskFamilyName:1 or arn:aws:ecs:us-east-1:111122223333:task-definition/TaskFamilyName:*), then set this value to arn:aws:ecs:us-east-1:111122223333:task-definition/TaskFamilyName:1.

For more information, see Policy Resources for Amazon ECS in the Amazon Elastic Container Service developer Guide.