Add variable validations for error prone variables

[malparty]

Why

Terraform allows the validation of variables. This comes with 2 benefits:

• avoid deploying an infra with invalid variables
• provide clear error messages about what is wrong and why (reduce the need for debugging the issue)

Of course, we might not want to validate ALL the variables, this issue should process with 2 steps:

• [ ] Identify what variables should be covered with what validations
• [ ] Implement the validations

Who Benefits?

Developers with better DevX (guidance and early errors), and users with less unexpected infrastructure deployed.

Resource

See this tutorial: Validate Variables