As infrastructure as code (IaC) becomes the standard for provisioning cloud resources, ensuring that Terraform plans, Kubernetes manifests, and CloudFormation templates comply with security and governance policies before deployment is critical. Policy as code tools like Open Policy Agent (OPA) and Checkov automate compliance validation in CI/CD pipelines.
Shifting Security Left with Policy as Code
OPA provides a general-purpose policy engine with its Rego query language, capable of evaluating any structured data against declarative policies. For Terraform, Conftest wraps OPA to validate plan files, catching violations like publicly accessible S3 buckets, missing encryption, or overly permissive IAM roles before terraform apply executes.
Checkov offers a batteries-included approach with hundreds of pre-built policies for Terraform, CloudFormation, Kubernetes, Helm, and Dockerfile security best practices. Its graph-based analysis can trace relationships between resources, identifying issues like security groups that reference public CIDR blocks connected to databases.
Integrating policy as code into pull request workflows provides immediate feedback to developers. Failed policy checks block merges, while auto-generated fix suggestions accelerate remediation. This approach scales security review across large organizations without creating bottlenecks in centralized security teams.