HashiCorp Terraform Associate (004) Question 12
Single answer1b Describe the advantages of IaC patternsA platform team manages separate development, staging, and production environments in AWS. Historically, engineers created networking, IAM, and compute resources manually in each environment, which led to configuration drift and inconsistent security settings. The team wants to adopt Terraform and standard Infrastructure as Code (IaC) patterns to improve reliability and speed while keeping environments aligned. Which approach best demonstrates the advantages of IaC patterns in this scenario?
- A
Create reusable Terraform modules for shared components such as VPCs and IAM roles, store the configuration in version control, and use plans to review proposed changes before applying them to each environment.
- B
Have each engineer maintain separate handwritten Terraform files for every environment so changes can be customized quickly without affecting other teams.
- C
Continue provisioning production manually for safety, but use Terraform only for development so the team can experiment without changing established operational processes.
- D
Use one-time Terraform runs to create the initial infrastructure, then allow teams to modify resources directly in the cloud console to reduce the need for future code updates.
Show answer and explanation
Correct answer: A
Explanation
The best answer is the option that uses reusable modules, version control, and plan review because it captures several foundational advantages of IaC patterns in Terraform: consistency, reusability, repeatability, collaboration, and reduced configuration drift. In Terraform, modules are a recommended way to encapsulate and standardize repeated infrastructure patterns across environments. Storing configuration in version control supports peer review, history, and rollback. Running terraform plan before terraform apply helps teams inspect proposed changes and reduce unintended modifications. These practices align with HashiCorp guidance around treating infrastructure as code, using modules for reuse, and relying on plan/apply workflows to manage infrastructure changes predictably. The alternatives all preserve manual processes or duplicated code, which are exactly the kinds of issues IaC is intended to address.
- A. Correct.
Correct. This approach reflects key IaC advantages and common Terraform patterns: reusable modules reduce duplication, version control provides change history and collaboration, and reviewing execution plans helps teams understand and validate infrastructure changes before apply. Together, these practices improve consistency, reduce drift, and make infrastructure changes more repeatable across environments.
- B. Incorrect.
Incorrect. Although environment-specific customization is sometimes necessary, maintaining separate handwritten configurations for each environment increases duplication and inconsistency. It weakens one of the core benefits of IaC patterns: standardization through reusable code. This often results in drift and makes it harder to review, test, and maintain infrastructure over time.
- C. Incorrect.
Incorrect. Using Terraform only for development may provide some automation benefits, but it does not solve the main problem of inconsistent environments. A major advantage of IaC is that the same reviewed and versioned patterns can be applied across environments, including production, to improve reproducibility and reduce manual errors. Keeping production manual preserves the inconsistency the team is trying to eliminate.
- D. Incorrect.
Incorrect. Treating Terraform as a one-time provisioning tool and then managing resources manually undermines the IaC model. Direct console changes introduce drift between real infrastructure and the configuration in code, making future plans less reliable and reducing auditability. Terraform is most effective when infrastructure changes continue to be managed through code.