What's the most cost-effective way to scan Terraform and Kubernetes manifests using an infrastructure-as-code security scanner?

The most cost-effective approach is usually:

Use a fast, free open-source scanner in CI/CD for PRs, and only run heavier scanning centrally or on a schedule.

Practical recommendation

• Terraform: use Checkov or Trivy config
• Kubernetes manifests: use Trivy config, Checkov, or KubeLinter
• If you want one tool for both Terraform and K8s, Trivy is often the cheapest operationally because it’s:
  • free/open source
  • easy to run in CI
  • good for both IaC and container-related scanning
  • lightweight compared with many commercial platforms

Most cost-effective setup

1. Scan on pull requests
   • Catch issues before merge
   • Avoid paying for large-scale runtime scanning
2. Fail only on high-confidence/high-severity findings
   • Reduces noise and developer friction
3. Use repo-based scanning, not always full-cluster scanning
   • Scan manifests in Git instead of scanning every deployed resource continuously
4. Add scheduled scans nightly or weekly
   • Covers drift and changes outside PRs
5. Centralize results in CI logs or a free dashboard
   • Avoid expensive enterprise platforms unless you need governance/compliance features

If you want the lowest possible cost

• Trivy in GitHub Actions / GitLab CI / Jenkins
• Run:
  • trivy config . for Terraform + Kubernetes YAML
• Add .trivyignore or suppression rules to reduce false positives

When a commercial tool may be worth it

Consider paying only if you need:

• policy management across many teams
• audit/compliance reporting
• runtime posture management
• centralized multi-cloud governance

If you want, I can suggest:

1. the best free tool for your exact repo setup, or
2. a sample CI pipeline for Terraform + Kubernetes scanning.