Infrastructure as Code (IaC)

Automate infrastructure provisioning and management using declarative configuration with Terraform, enabling version-controlled, repeatable, and scalable infrastructure deployment.

Level 1: Quick Reference

Core Workflow

# Initialize Terraform
terraform init

# Preview changes
terraform plan -out=tfplan

# Apply changes
terraform apply tfplan

# Destroy infrastructure
terraform destroy

# Validate configuration
terraform validate

# Format code
terraform fmt -recursive

Essential Patterns

Basic Resource:

resource "aws_instance" "web" {
  ami           = var.ami_id
  instance_type = var.instance_type

  tags = {
    Name        = "${var.environment}-web"
    Environment = var.environment
  }
}

Module Usage:

module "vpc" {
  source  = "terraform-aws-modules/vpc/aws"
  version = "~> 5.0"

  name = "${var.environment}-vpc"
  cidr = var.vpc_cidr

  azs             = var.availability_zones
  private_subnets = var.private_subnet_cidrs
  public_subnets  = var.public_subnet_cidrs

  enable_nat_gateway = true
  enable_vpn_gateway = false
}

Remote State:

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

Critical Checklist

• Pin provider versions (version = "~> 5.0")
• Enable remote state with locking
• Use workspaces for environments
• Implement .gitignore for secrets
• Run terraform validate before commit
• Review plan output before apply
• Tag all resources consistently
• Use variables for all environment-specific values
• Document module inputs/outputs
• Enable state encryption

Common Commands

# Workspace management
terraform workspace new dev
terraform workspace select prod
terraform workspace list

# State management
terraform state list
terraform state show aws_instance.web
terraform state mv aws_instance.old aws_instance.new
terraform state rm aws_instance.deprecated

# Import existing resources
terraform import aws_instance.web i-1234567890abcdef0

# Output values
terraform output
terraform output -json vpc_id

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Level 2:

📚 Full Examples: See REFERENCE.md for complete code samples, detailed configurations, and production-ready implementations.

Implementation Guide

1. Terraform Fundamentals

Project Structure

See REFERENCE.md for complete implementation.

Provider Configuration

See REFERENCE.md for complete implementation.

Resources and Data Sources

See REFERENCE.md for complete implementation.

2. Module Development

Module Structure

See REFERENCE.md for complete implementation.

Module Versioning

See REFERENCE.md for complete implementation.

3. State Management

S3 Backend Configuration

See REFERENCE.md for complete implementation.

Backend Initialization Script

See REFERENCE.md for complete implementation.

State Operations

See REFERENCE.md for complete implementation.

4. Workspace Strategies

Environment Workspaces

See REFERENCE.md for complete implementation.

Workspace-Based Configuration

See REFERENCE.md for complete implementation.

5. Testing Infrastructure as Code

Terraform Validate and Format

See REFERENCE.md for complete implementation.

TFLint Configuration

See REFERENCE.md for complete implementation.

Terratest Example

See REFERENCE.md for complete implementation.

6. CI/CD Integration

GitHub Actions Workflow

See REFERENCE.md for complete implementation.

GitLab CI Pipeline

See REFERENCE.md for complete implementation.

7. Multi-Cloud Configuration

AWS + Azure Example

See REFERENCE.md for complete implementation.

GCP Configuration

See REFERENCE.md for complete implementation.

8. Security Best Practices

Secrets Management

See REFERENCE.md for complete implementation.

IAM Policy Best Practices

See REFERENCE.md for complete implementation.

Resource Encryption

See REFERENCE.md for complete implementation.

9. Drift Detection and Remediation

Drift Detection Script

See REFERENCE.md for complete implementation.

Automated Remediation

See REFERENCE.md for complete implementation.

Scheduled Drift Checks (Cron)

# /etc/cron.d/terraform-drift-check
# Run drift detection daily at 2 AM
0 2 * * * terraform cd /opt/terraform/infrastructure && ./scripts/detect-drift.sh prod

10. Advanced Patterns

Dynamic Blocks

See REFERENCE.md for complete implementation.

For Expressions

See REFERENCE.md for complete implementation.

Conditional Resources

See REFERENCE.md for complete implementation.

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Level 3: Deep Dive Resources

Official Documentation

• Terraform Documentation
• Terraform Registry
• AWS Provider Documentation
• Azure Provider Documentation
• GCP Provider Documentation

Testing and Validation

• Terratest Documentation
• TFLint Rules
• Checkov - Infrastructure Security
• Terraform Compliance

Best Practices and Guides

• Terraform Best Practices
• Gruntwork Production Guide
• HashiCorp Learn
• AWS Well-Architected

Community Resources

• Awesome Terraform
• Terraform Community Modules
• Terraform Patterns

Books

• "Terraform: Up & Running" by Yevgeniy Brikman
• "Terraform in Action" by Scott Winkler
• "Infrastructure as Code" by Kief Morris

Tools and Extensions

• Terraform-docs - Generate documentation
• Infracost - Cloud cost estimates
• Rover - Interactive visualization
• Terraform Graph - Dependency graphs

Examples

Basic Usage

// TODO: Add basic example for infrastructure-as-code
// This example demonstrates core functionality

Advanced Usage

// TODO: Add advanced example for infrastructure-as-code
// This example shows production-ready patterns

Integration Example

// TODO: Add integration example showing how infrastructure-as-code
// works with other systems and services

See examples/infrastructure-as-code/ for complete working examples.

Integration Points

This skill integrates with:

Upstream Dependencies

• Tools: Common development tools and frameworks
• Prerequisites: Basic understanding of general concepts

Downstream Consumers

• Applications: Production systems requiring infrastructure-as-code functionality
• CI/CD Pipelines: Automated testing and deployment workflows
• Monitoring Systems: Observability and logging platforms

Related Skills

• See other skills in this category

Common Integration Patterns

1. Development Workflow: How this skill fits into daily development
2. Production Deployment: Integration with production systems
3. Monitoring & Alerting: Observability integration points

Common Pitfalls

Pitfall 1: Insufficient Testing

Problem: Not testing edge cases and error conditions leads to production bugs

Solution: Implement comprehensive test coverage including:

• Happy path scenarios
• Error handling and edge cases
• Integration points with external systems

Prevention: Enforce minimum code coverage (80%+) in CI/CD pipeline

Pitfall 2: Hardcoded Configuration

Problem: Hardcoding values makes applications inflexible and environment-dependent

Solution: Use environment variables and configuration management:

• Separate config from code
• Use environment-specific configuration files
• Never commit secrets to version control

Prevention: Use tools like dotenv, config validators, and secret scanners

Pitfall 3: Ignoring Security Best Practices

Problem: Security vulnerabilities from not following established security patterns

Solution: Follow security guidelines:

• Input validation and sanitization
• Proper authentication and authorization
• Encrypted data transmission (TLS/SSL)
• Regular security audits and updates

Prevention: Use security linters, SAST tools, and regular dependency updates

Best Practices:

• Follow established patterns and conventions for infrastructure-as-code
• Keep dependencies up to date and scan for vulnerabilities
• Write comprehensive documentation and inline comments
• Use linting and formatting tools consistently
• Implement proper error handling and logging
• Regular code reviews and pair programming
• Monitor production metrics and set up alerts

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Next Steps

After mastering Infrastructure as Code:

1. Advanced DevOps: CI/CD pipelines, GitOps workflows
2. Container Orchestration: Kubernetes with Terraform
3. Security: Cloud security posture management
4. FinOps: Cloud cost optimization strategies
5. Observability: Infrastructure monitoring and alerting