k8s cluster security best practices
1. Secure API Access
- Use RBAC (Role-Based Access Control): Restrict permissions based on the principle of least privilege.
- Disable Anonymous Access: Ensure all API requests are authenticated.
- Enable Audit Logging: Monitor and log API activity to detect anomalies.
- Use Network Policies: Restrict API access to trusted sources.
2. Secure Authentication & Authorization
- Use Strong Authentication: Rely on an identity provider (OIDC, Active Directory, etc.).
- Enable Multi-Factor Authentication (MFA): Strengthens access security.
- Limit Service Account Permissions: Avoid giving service accounts excessive privileges.
3. Secure Cluster Networking
- Use Network Policies: Restrict pod-to-pod communication based on necessity.
- Enable Encryption in Transit: Use TLS for securing API server, ETCD, and service communications.
- Restrict External Access: Expose only necessary services using Ingress controllers.
4. Protect ETCD Database
- Enable Encryption at Rest: Encrypt sensitive data stored in ETCD.
- Restrict Access to ETCD: Allow access only to the API server and use strong authentication.
- Regular Backups: Ensure ETCD is backed up regularly and stored securely.
5. Secure Workloads & Pods
- Use Pod Security Standards (PSS) or Pod Security Admission (PSA): Restrict privileges for pods.
- Enable Seccomp and AppArmor: Use security profiles to limit system calls.
- Avoid Running as Root: Use runAsUser and runAsNonRoot to enforce non-root execution.
- Restrict Privileged Containers: Prevent containers from running with excessive privileges.
6. Secure Supply Chain & Image Security
- Use Trusted Container Images: Always pull images from verified sources.
- Sign and Verify Images: Use tools like Cosign or Docker Content Trust.
- Scan Images for Vulnerabilities: Utilize tools like Trivy, Clair, or Anchore.
- Restrict Image Registries: Allow deployments only from trusted registries.
7. Limit Resource Access
- Enforce Resource Quotas & Limits: Prevent resource exhaustion by setting CPU/memory limits.
- Use Admission Controllers: Enforce security policies before workloads are created.
- Disable Default Service Account Auto-Mounting: Prevent unnecessary service account access.
8. Secure Logging & Monitoring
- Use Security Information and Event Management (SIEM) Tools: Aggregate logs for real-time analysis.
- Enable Kubernetes Audit Logs: Detect unauthorized API actions.
- Monitor Containers and Nodes: Use Prometheus, Falco, or Sysdig for runtime security.
9. Protect Against Network Attacks
- Enable CNI Plugins with Security Features: Calico, Cilium, or Antrea provide additional security.
- Enforce Egress and Ingress Rules: Restrict network traffic using NetworkPolicies.
- Use Service Mesh for Encryption: Istio or Linkerd provide mutual TLS for service-to-service communication.
10. Keep Kubernetes and Dependencies Updated
- Regularly Patch and Upgrade Kubernetes: Stay up to date with the latest security patches.
- Upgrade Third-Party Plugins & Dependencies: Keep Helm charts and other dependencies current.