When it comes to Azure, I always prefer to implement infrastructure-as-a-code through ARM template than Terraform, but that is not always a choice; It is called life. Love it or not, sometimes you need to implement your infrastructure-as-a-code with Terraform and believe me or not, maintaining a large codebase of Terraform is not the most interesting job in the world. Introducing a change in a infrastructure-as-a-code’s code is always error prone and hard to test. Well, it shouldn’t be. Terratest helps you to write automated tests for your Terraform code. A Go Library which helps you to test your Terraform code, Packer templates and Docker images.
The good news is, starting with Terratest is simple and straightforward. You just need to Install Go first (This was the hardest part for me to convince myself to install Go 🙂 ), and then you just need to add Terratest to your project through one of the Go dependency manager such as dep.
dep ensure -add github.com/gruntwork-io/terratest
You are all setup now. You just need to write your tests using Go’s built-in package testing and then use Terratest to execute your Terraform code to deploy the infrastructure to your environment; And then, use Terratest tools to validate your infrastructure (E.g. Making HTTP or API calls). When you finished with your testings you simply need to tear down the environment.
This way you simply can apply changes to your Terraform code with confidence.