Container Security Best Practices for Teams

Containers help teams move fast, but security should not be an afterthought. A practical approach uses layered controls across the build, the runtime, and day-to-day operations. This guide shares concrete steps teams can adopt without slowing delivery.

Build and image security

  • Start with small, verified base images and remove unnecessary packages.
  • Scan images for known vulnerabilities before they reach production.
  • Sign images and require verification before deployment.
  • Keep an up-to-date SBOM (software bill of materials) for every artifact.
  • Run containers as non-root users and drop privileges when possible.
  • Minimize layers and clean temporary files during image creation.

Runtime controls

  • Enforce the least privilege model; drop capabilities not needed by the app.
  • Run containers in read-only mode where feasible.
  • Apply network segmentation and policy rules to limit east-west traffic.
  • Use runtime security tools to detect unusual processes or file changes.
  • Enable profile-based security (seccomp, AppArmor, or SELinux) for each workload.
  • Collect centralized logs and metrics for quick investigation.

Secrets and configuration

  • Never embed secrets in images or code.
  • Use secret stores or vaults; fetch credentials at runtime with strict limits.
  • Rotate tokens and use short-lived credentials when possible.
  • Encrypt secrets in transit and at rest; protect with access controls.
  • Prefer volumes or secret mounts over environment variables.

Access and identity

  • Apply the principle of least privilege to service accounts and users.
  • Use RBAC with clear role boundaries; review bindings regularly.
  • Avoid running containers as root; specify a dedicated user.
  • Restrict container capabilities to only what the app needs.

CI/CD and supply chain

  • Scan dependencies and vulnerabilities in the pipeline; gate gates before publishing.
  • Sign and verify images as part of the release process.
  • Maintain an up-to-date SBOM and enforce policy-as-code checks.
  • Use trusted registries and restrict who can publish or push images.
  • Automate remediation workflows for detected issues.

Incident readiness and governance

  • Centralize logging, tracing, and alerting for quick response.
  • Prepare runbooks and perform tabletop drills regularly.
  • Review security controls after incidents and update defenses accordingly.

Key Takeaways

  • Build secure images, sign and verify them, and keep artifacts traceable.
  • Run with least privilege and strong runtime controls to limit risk.
  • Treat secrets as first-class data with proper storage and rotation.