Default Kubernetes configurations prioritize ease of use over security, creating vulnerabilities in production deployments. Hardening Kubernetes requires implementing defense-in-depth strategies across multiple layers—authentication and authorization, network security, container security, and secrets management. European organizations must secure clusters against both external attacks and insider threats.
Role-Based Access Control
RBAC controls who can perform which actions on Kubernetes resources. Principle of least privilege guides role definition—users receive minimum permissions needed for their responsibilities. Service accounts enable workload authentication. Namespace isolation separates teams and applications. Regular RBAC audits identify overly permissive policies requiring tightening.
- Define roles with minimal permissions following least privilege principle
- Use namespaces to isolate teams and applications from each other
- Implement service accounts for workloads avoiding shared credentials
- Audit RBAC policies regularly identifying unused or excessive permissions
- Enable audit logging capturing all API server access for security monitoring
Network Security
Network policies control traffic between pods, preventing lateral movement during security breaches. Default deny policies block all traffic except explicitly allowed connections. Ingress controls limit external access points. Egress controls prevent compromised pods from calling out to attacker infrastructure. Service mesh implementations provide encryption and authentication for inter-pod communication.
Container Security
Pod Security Standards restrict container capabilities preventing privilege escalation. Running containers as non-root reduces impact of container escapes. Read-only root filesystems prevent runtime modifications. Security context configurations drop unnecessary Linux capabilities. Image scanning detects vulnerabilities before deployment. These layers combine to limit container compromise impact.