How do you see the ideal structure of a Terraform project? What components should it consist of when there are multiple environments (dev, stage, prod)?

The ideal structure of a Terraform project with multiple environments is usually built on separating configurations by environment and reusing modules.

Main components:

1. Modules — reusable infrastructure blocks, such as a module for creating networks, modules for configuring databases, VMs, etc. They are stored in a separate modules/ folder.

2. Environments — separate directories for each environment (dev/, stage/, prod/), containing configurations that use modules with parameters tailored to each environment.

3. Backend and state — each environment is configured with a separate backend (e.g., S3, Terraform Cloud) for storing state, ensuring complete environment isolation.

4. Variables and secrets — environment parameters are set through variables.tf and variable files (dev.tfvars, prod.tfvars), secrets are better stored in secure storage (Vault, AWS Secrets Manager).

Example structure:

terraform-project/
├── modules/
│   ├── network/
│   ├── compute/
│   └── database/
├── dev/
│   ├── main.tf
│   ├── variables.tf
│   └── terraform.tfvars
├── stage/
│   ├── main.tf
│   ├── variables.tf
│   └── terraform.tfvars
└── prod/
    ├── main.tf
    ├── variables.tf
    └── terraform.tfvars

In each environment, main.tf calls modules with the necessary parameters. This approach ensures code reuse, environment isolation, and ease of maintenance.