Infrastructure as Code Terraform automation

Implement Infrastructure as Code using Terraform for scalable, repeatable infrastructure provisioning. Terraform best practices: 1. Module structure: reusable components, input variables, output values, documentation. 2. State management: remote backends (S3 + DynamoDB), state locking, team collaboration. 3. Version control: semantic versioning for modules, branch protection, code reviews. 4. Testing: terraform plan validation, terratest for integration testing. Multi-environment strategy: 1. Workspace separation: dev, staging, production with environment-specific variables. 2. Configuration management: tfvars files, environment variable injection. 3. Deployment pipeline: automated testing, approval workflows, drift detection. Resource provisioning: 1. Cloud provider modules: AWS VPC, EC2, RDS with appropriate sizing and security groups. 2. Networking: subnets, route tables, NAT gateways, VPN connections. 3. Security: IAM roles, security groups, encryption at rest/transit. Cost optimization: 1. Resource tagging: cost allocation, environment identification, automated cleanup. 2. Right-sizing: instance types based on performance requirements, reserved instances for predictable workloads. Security scanning: Checkov, tfsec for policy compliance, secret detection, vulnerability assessment. Documentation: README files, module documentation, architecture diagrams.