Template format error: unsupported structure seen in AWS CloudFormation

Question

I am trying to validate an AWS example CloudFormation template using a command like:

▶ aws cloudformation validate-template --template-body template.yml
<         


        

Answer 1

Apparently, the very unhelpful error message comes as a result of improper formatting in the CLI command.

The --template-body argument must be specified as a file URI.

Thus, the correct, runnable form of the command above is:

▶ aws cloudformation validate-template --template-body file://template.yml

See this blog post for more information.