Terraform AWS Best Practices for Production

Introduction

Managing AWS infrastructure with Terraform is powerful, but doing it correctly at scale requires following best practices. This guide covers essential patterns and practices that will help you maintain reliable, secure, and scalable infrastructure.

1. Project Structure

Organize your Terraform code into logical modules and environments:

terraform/
├── environments/
│   ├── dev/
│   ├── staging/
│   └── production/
├── modules/
│   ├── networking/
│   ├── compute/
│   └── database/
└── global/
    └── iam/

2. Use Remote State

Always use remote state backends for team collaboration and state locking:

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

3. Implement State Locking

Use DynamoDB for state locking to prevent concurrent modifications and potential state corruption. This is critical for team environments.

4. Use Workspaces Wisely

While workspaces can be useful, prefer separate state files for different environments to avoid accidental modifications.

5. Secrets Management

Never hardcode secrets. Use AWS Secrets Manager or Parameter Store:

data "aws_secretsmanager_secret_version" "db_password" {
  secret_id = "production/db/password"
}

resource "aws_db_instance" "main" {
  password = data.aws_secretsmanager_secret_version.db_password.secret_string
}

6. Resource Tagging Strategy

Implement consistent tagging across all resources for cost tracking and organization:

locals {
  common_tags = {
    Environment = var.environment
    ManagedBy   = "Terraform"
    Project     = "MyApp"
    CostCenter  = "Engineering"
  }
}

7. Use Data Sources

Leverage data sources to reference existing resources and reduce duplication:

data "aws_ami" "amazon_linux" {
  most_recent = true
  owners      = ["amazon"]
  
  filter {
    name   = "name"
    values = ["amzn2-ami-hvm-*-x86_64-gp2"]
  }
}

8. Implement CI/CD

Automate terraform plan and apply using CI/CD pipelines. Always run plans on pull requests and require approval before applying.

Conclusion

Following these best practices will help you build maintainable, secure, and scalable AWS infrastructure with Terraform. Start with these fundamentals and adapt them to your organization's specific needs.