How can I find the root cause for AWS CloudFormation stack creation failure?

Question

I am trying to install a simple stack using AWS CloudFormation. I create an IAM user and also pass in some script to install puppet and git thru userdata so that it can be executed by cloudinit.

The problem is for some reason the template fails mid way and the stack creation is rolled back. I am doing this thru the management gui. But it doesn't tell me why it fails. I can see that some of the resources are created and then it fails. Is there a way to look at detailed logs to see what exactly is failing?

Answer 1

The AWS Management Console for AWS CloudFormation offers an Events tab in the stack detail panel, which lists the stack life-cycle events and features a Reason column in turn, which contains more details for the errors in case.

This column exposes the ResourceStatusReason field of the StackEvent data type retrieved via the DescribeStackEvents action:

ResourceStatusReason - Success/failure message associated with the resource