Infrastructure as Code

🔑 Key Takeaway: Treat infrastructure definitions as production code—review them, scan them, and apply least privilege—because a bad template can recreate a bad estate at scale.

Infrastructure as Code (IaC) provisions and manages infrastructure from machine-readable definitions instead of one-off console clicks. Automating security around IaC helps environments stay consistent and reduces recurring misconfigurations.

Benefits of securing IaC

1. Consistency
   • Same definitions across environments reduce snowflake risks.
   • Lower chance of silent manual drift (when humans stop “fixing prod by hand”).
2. Scalability
   • Secure patterns encode once and deploy many times.
3. Version control
   • History, code review, and rollback become available for infrastructure changes.

Practices

1. Use trusted modules
   • Prefer verified modules or templates.
   • Avoid unverified or abandoned modules that may ship weak defaults.
2. Implement least privilege
   • Grant infrastructure components only required permissions.
   • Use role-based access control (RBAC) and short-lived credentials where possible (see IAM).
3. Automate security scans
   • Integrate scanners into the IaC pipeline.
   • Common Terraform-oriented options cited by practitioners include Checkov, tfsec, and Terrascan—evaluate current fit for the stack.
4. Encrypt sensitive data
   • Encrypt sensitive data at rest and in transit as the platform allows.
   • Prefer managed key services over bespoke secret sprawl (see Encryption).
5. Keep templates current
   • Update modules and base images or AMIs as vendors fix issues.
   • Re-review high-risk stacks when threat models change.

Tools and platforms

Capability matrix changes frequently; treat this as a starting catalog.

1. Terraform — multi-cloud IaC with a large module ecosystem; commonly paired with policy and scan tools.
2. AWS CloudFormation — native AWS IaC; pairs with AWS Config-style compliance evaluation.
3. Azure Resource Manager (ARM) / Bicep templates — Azure native IaC; pairs with Azure Policy.
4. Ansible — configuration management and deployment automation; use hardened roles and avoid shipping secrets in plain playbooks.

Further reading

• Checkov
• tfsec
• Terrascan
• OWASP Infrastructure as Code Security Cheat Sheet (if maintained for the target version, verify content currency)
• Project DevSecOps