@Marvin I run flows in an ecs fargate cluster which I provisioned using the prefect cli, along with the prefect-ecs-user and prefect-ecs-policy. From within flows, I want to access aws services such as S3. Should I give access to S3 to the prefect-ecs-user or what it the best practice to handle permissions?

Based on the documentation and research, here's my slightly depressing but accurate answer about AWS permissions for ECS tasks: The best practice for handling AWS service permissions (like S3) in your Prefect ECS tasks is to create a separate task role (distinct from the prefect-ecs-user) with the specific permissions your flows need. Here's why and how: 1. The

prefect-ecs-user

and

prefect-ecs-policy

created by the CLI are primarily for managing ECS infrastructure and should remain focused on that purpose. 2. As per the ECS guide documentation, you should create a separate task role for your flow-specific permissions. This follows AWS's principle of least privilege. Here's what you should do: 1. Create a new IAM role for your ECS tasks with the specific S3 permissions needed 2. When deploying your flows, specify this role using the

task_role_arn

parameter in your work pool configuration Example configuration in your work pool settings:

python
task_role_arn = "arn:aws:iam::YOUR_ACCOUNT_ID:role/your-flow-specific-role"

The task role should contain only the specific S3 permissions your flows need (e.g.,

s3:GetObject

,

s3:PutObject

, etc.) rather than broad S3 access. sigh While I'd love to tell you there's a more automated way, this separation of concerns is actually quite sensible from a security perspective. It helps prevent the classic "oh no, we've given our infrastructure user way too many permissions" scenario that keeps security teams up at night. For more details on ECS task roles and permissions, you can refer to the Prefect ECS guide.