Best practices for securing containerized applications and orchestration platforms like Kubernetes.
Container Fundamentals
Containerized applications require specialized security controls including image scanning, runtime protection, network policies, and access control. Containers share the kernel, making isolation less complete than virtual machines. Kubernetes security involves securing the control plane, securing workloads, and implementing network segmentation.
Image Security
Container images should be scanned for vulnerabilities before deployment. Organizations should implement image signing and verify signatures before running containers. Vulnerable images should never reach production.
Kubernetes Security
Kubernetes clusters require security at multiple layers: API server authentication, RBAC for authorization, pod security policies, and network policies. The control plane is a high-value target and deserves particular attention.
Runtime Protection
Runtime policies should prevent unexpected process execution, network access, and file system modifications. Kubernetes Pod Security Policies enforce these controls. Runtime behavioral monitoring detects anomalies.
Network Policies
Kubernetes network policies segment traffic between pods. Organizations should implement deny-by-default policies and explicitly allow necessary traffic.
Registry and Supply Chain
Container registries should enforce authentication, scan images for vulnerabilities, and prevent unsigned images from running.