dev v2.0 overhaul

[zachreborn]

This PR is for a massive overhaul of our terraform-modules. Including:

• Removing unused modules which were built in pre terraform v0.12
• Removing modules which need a complete rebuild due to resource blocks and best practices changing
• Automating the CI/CD pipeline for this repository
• tfsec improvements
• tflint improvements

[zachreborn]

Overview

Since we first began working on terraform modules, terraform has changed a lot and so have we! This update begins a new major version which will not be backward compatible with v1. In part, this is because we're exclusively supporting terraform >=v1.0 and it also is because we needed to do some tidying up of our code and folder structure.

Highlights

• Going forward, modules for a major service will be within a folder structure indicating the service. This means that many modules have moved down a level in the following format './module_long_name' will be moving to './module/name'. Examples:
  • ./route53_zone -> ./route53/zone
  • ./route53_record -> ./route53/simple_record
  • ./fortigate_firewall -> ./vendor/fortigate_firewall
  • ./corelight -> ./vendor/corelight
• Modules now use validation
  • Variables are now using validation where applicable to provide better feedback through unit testing for each module.
• CI/CD automation improvements
  • The CI/CD automation has been improved and moved to Github Actions. This is to simplify the workflows and have more direct integration with engineers and developers working on deployments.
  • test.yml now tests the terraform code as well as lints it
  • build.yml now generates terraform-docs and formats the code with 'terraform fmt -recursive'
• README updates
  • You'll notice the readme has a new robot overseeing our work. We wanted to create a little mascot for something fun.
  • We're using the 'Best-README-Template' customized to our liking. Be sure to check it out at https://github.com/othneildrew/Best-README-Template if you'd like to utilize this excellent readme.

What that means for you

• Can only impact existing AWS resources
• Less than 10% of existing AWS resources will be unable to be upgraded
  • These resources will need to be either rebuilt on the latest, or removed from terraform state and re-imported in with the latest version over the next year or so
• If you upgrade existing AWS resources, be sure to validate that the folder structure for the source has not moved. If it still errors, verify that the argument or variable names haven't changed. If you still have errors, please open an issue and we'll resolve ASAP.