Securing the CI/CD Supply Chain

Supply chain attacks, like the infamous SolarWinds breach, have highlighted the critical need to secure the pipeline that builds and delivers our software. A compromised CI/CD pipeline translates to compromised production environments.

Image Signing with Sigstore (Cosign)

How do you know the container image running in your cluster is the exact one built by your CI system? Cosign, part of the Sigstore project, allows you to sign container images and artifacts.

Kubernetes admission controllers can then be configured to reject any pod that attempts to run an unsigned image.

Continuous Vulnerability Scanning

Integrating tools like Trivy or Grype into your CI pipeline is non-negotiable. Images should be scanned for known CVEs before they are pushed to the registry.

Furthermore, running continuous scans against your registry ensures you are alerted to new vulnerabilities found in already deployed images.

Policy Enforcement with OPA Gatekeeper

Open Policy Agent (OPA) Gatekeeper allows you to enforce policies across your Kubernetes clusters. For example, you can write policies that: - Forbid running containers as root. - Require specific labels on deployments. - Enforce the use of read-only root filesystems.

Conclusion

Securing the software supply chain requires a defense-in-depth approach, encompassing code signing, vulnerability scanning, and strict policy enforcement at deployment time.