cannot run ecs container on ec2 instance in private subnet

Question

I'm trying to run the container of a service I created with AWS ECS. But the ecs agent on the EC2 instance fails to retrieve some configuration from an AWS managed s3 bucket:

Failed to pull image ...........dkr.ecr.eu-west-1.amazonaws.com/........:latest: error pulling image configuration: Get https://prod-eu-west-1-starport-layer-bucket.s3-eu-west-1.amazonaws.com/.......: dial tcp 54.231.141.131:443: i/o timeout

the instance is running in a private subnet, that I configured using this tutorial .

I can curl www.google.co.uk from the instance, but I cannot ping/curl s3-eu-west-1.amazonaws.com , which I can from my computer and from a bastion on the public subnet associated to the same VPC.

The issue looks similar to the unsolved question ECS agent can not successfully pull image from ECR but my problem is just about retrieving that configuration from that s3 bucket.

Answer 1

You need to whitelist/ allow outbound access to https://prod-eu-west-1-starport-layer-bucket.s3-eu-west-1.amazonaws.com from your ecs instances because it is used internally by AWS to manage ECR image layers.

Check the below references for more details : https://docs.aws.amazon.com/AmazonECR/latest/userguide/ecr-minimum-s3-perms.html https://github.com/awsdocs/amazon-ecr-user-guide/issues/8#start-of-content