EFS mount in ECS "Failed to resolve"

Question

I am trying to create a Fargate container with a mounted EFS volume via access point, all being created through cloudformation. I see the EFS created in the portal however the ECS task is failing with:

Failed to resolve "fs-XXX.efs.eu-west-2.amazonaws.com" - check that your file system ID is correct

Before adding the accesspoint the mounting worked. I need the accesspoint since the container is using non-root user.

The VPC has DNS and hostname lookup enabled.

Here is the cloudformation template: https://pastebin.com/CgtvV17B

user_310298 · Answer

the problem was missing EFS Mount Target https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-efs-mounttarget.html

user_1860511 · Answer

I think the fargate tasks can't reach the EFS system, check that the EFS subnets are reachable from the Fargate ( deployed in the same subnets at least), and the route tables are well configured. The security group of the ECS and EFS are well configured ( check if your EFS authorize the TCP 2049).

Also check the version of the Fargate, I think its working with EFS just for the version > 1.4

Try to deploy an instance EC2 with the same configuration ( same VPC and subnet properties ) and check if it can reach the EFS.

EFS mount in ECS "Failed to resolve"

2 Answers