How can I quickly and effectively debug CloudFormation templates?

Question

CloudFormation is a powerful AWS offering that allows the programmatic creation of AWS resource stacks, such as the web tier of an application, a high performance computing

Answer 1

If you are dealing with EC2 machines, then I would recommend you to login to the EC2 machine and tail the boot.log file (/var/log/boot.log in RHEL6/Centos). This file gets updated with all your shell activities (activities like: installation, downloading files, copying files etc.).

Also, use editors like http://www.jsoneditoronline.org/ to get a TREE representation of your JSON. This helps you to check the order of JSON elements.

And when you update files always use tools like http://www.git-tower.com/blog/diff-tools-mac/ or an actual version control system to ensure that you did not accidentally change something which might break your script.