Terraform is an unbelievably powerful and efficient tool for managing infrastructure as code. However, with great power comes great responsibility. To get the most out of Terraform, there are certain best practices every user should follow.
1. Understand the Destroy Command
The Terraform destroy command can reverse almost any operation Terraform has performed when applied to an existing environment. It is essential that your Terraform scripts are configured such that running the destroy command, either intentionally or accidentally, will not unintentionally cause disruption or damage to your environment.
2. Use Terraform Version Control
Running Terraform scripts directly against production environments can be risky. It is recommended that you use version control on all of your Terraform scripts. Version control will also provide you with an opportunity to review every change before applying it, as well as undo past changes as needed.
3. Pre-Check with Terraform Plan
Before applying any changes, you should pre-check them with the terraform plan command. This will list the changes that Terraform intends to make, allowing you to review them beforehand. If any unintended changes are listed, you can deny the plan before any changes are made.
4. Lock Down Access
Secure access to your Terraform scripts should be provided only to those users who need access, and that access should be based on least privilege. By keeping access to your scripts limited and using version control, you can minimize the potential for malicious or inadvertent modifications to your infrastructure.
5. Dividing Into State Files
Terraform can manage multiple environments in the same script. It is recommended that you divide them into separate state files for easier tracking and management. For larger and more complex infrastructure, you may want to further divide them into different layers (e.g. backend, front-end, and middleware).
6. Use Terraform Remote State
Terraform works best when using remote state. Remote state provides a shared source of truth and allows multiple users to collaborate on a common infrastructure. It also prevents individual users from making changes that could impact an infrastructure unknowingly and unintentionally.
7. Logging
Terraform logs provide an invaluable resource when diagnosing issues. They should be reviewed regularly to ensure they are up-to-date and proper tracking of changes is being performed.
By following these best practices, you can ensure that your Terraform scripts are functioning as intended and that your environment is as secure and robust as possible. The simple steps outlined in this post can help to ensure that Terraform is being used to its fullest potential.
