Terraform Best Practices for Multi-Environment Infrastructure

When managing infrastructure across multiple environments (lab, dev, staging, production), it’s crucial to follow best practices that ensure consistency, maintainability, and scalability.

Use Terraform Modules

One of the most powerful features of Terraform is its module system. By creating reusable modules, you can:

• Reduce code duplication
• Ensure consistency across environments
• Simplify maintenance and updates
• Enable team collaboration

Example Module Structure

modules/
  vpc/
    main.tf
    variables.tf
    outputs.tf
  ec2-instance/
    main.tf
    variables.tf
    outputs.tf

Separate State Files Per Environment

Each environment should have its own state file. This prevents accidental changes to production when working in development and provides better isolation.

terraform {
  backend "s3" {
    bucket         = "terraform-state-prod"
    key            = "vpc/terraform.tfstate"
    region         = "us-east-1"
    dynamodb_table = "terraform-locks"
    encrypt        = true
  }
}

Use Variable Files for Environment-Specific Configuration

Create separate .tfvars files for each environment:

• lab.tfvars
• dev.tfvars
• prod.tfvars

This approach keeps environment-specific values separate from your module logic.

Implement Remote State Locking

Always use remote state with locking to prevent concurrent modifications:

• Use S3 + DynamoDB for AWS
• Enable encryption at rest
• Implement proper IAM policies

Version Your Terraform Providers

Always specify provider versions in your configuration to ensure reproducible builds:

terraform {
  required_version = ">= 1.0"
  required_providers {
    aws = {
      source  = "hashicorp/aws"
      version = "~> 5.0"
    }
  }
}

Conclusion

Following these best practices will help you build scalable, maintainable infrastructure that can grow with your organization. Start with these fundamentals and iterate as your needs evolve.