IaC with Terraform & Terragrunt: Benefits and Trade-offs

Infrastructure-as-Code with Terraform brings reproducibility, reviewable diffs, and automation to infrastructure changes. Terragrunt is a thin wrapper that helps organize Terraform code across environments: it enables DRY patterns, shared remote-state configuration, and convenient environment-level orchestration.

Key benefits of using Terragrunt include centralized backend/remote state configuration, easy management of per-environment inputs, and simple composition of modules through include and dependencies blocks. Terragrunt can reduce copy-paste across many environments and makes promoting changes between environments more predictable.

However, Terragrunt adds an extra layer of abstraction and tooling: it introduces its own configuration conventions and a learning curve. Debugging can be more complex because you must reason about both Terragrunt-generated Terraform configurations and the underlying Terraform modules. Upgrades and breaking changes in Terragrunt or Terraform may also require coordinated updates.

Trade-offs to consider:

• Benefits: DRY configs, consistent remote state and locking, easier orchestration across stacks, and per-environment overrides without duplicating module code.
• Downsides: additional complexity, potential for tight coupling between stacks, harder local debugging, and operational overhead around versioning and CI workflows.

In practice, use Terragrunt when you have multiple similar environments or many replicated stacks where the DRY payoff outweighs the extra layer. For small projects or when teams prefer minimal tooling, standard Terraform with well-structured modules may be simpler and easier to maintain.