Kubernetes Security Best Practices for Production

Kubernetes has become the de facto standard for container orchestration, but securing Kubernetes clusters requires careful attention to multiple layers of the stack.

Core Security Principles

1. Least Privilege Access

Implement RBAC (Role-Based Access Control) strictly:

apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  namespace: production
  name: pod-reader
rules:
- apiGroups: [""]
  resources: ["pods"]
  verbs: ["get", "list"]

2. Network Policies

Control traffic between pods:

apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: deny-all-ingress
spec:
  podSelector: {}
  policyTypes:
  - Ingress

3. Pod Security Standards

Use Pod Security Admission to enforce security policies:

• Privileged: Unrestricted (avoid in production)
• Baseline: Minimally restrictive
• Restricted: Heavily restricted (recommended)

Container Security

Image Security

• Use minimal base images
• Scan images for vulnerabilities
• Sign and verify images
• Use private registries

Runtime Security

• Run containers as non-root
• Use read-only root filesystems
• Drop unnecessary capabilities
• Set resource limits

Secrets Management

Never store secrets in plain text:

• Use Kubernetes Secrets with encryption at rest
• Consider external secret management (Vault, AWS Secrets Manager)
• Rotate secrets regularly
• Audit secret access

Monitoring and Auditing

Enable Audit Logging

apiVersion: audit.k8s.io/v1
kind: Policy
rules:
- level: Metadata
  resources:
  - group: ""
    resources: ["secrets"]

Runtime Monitoring

• Deploy security monitoring tools (Falco, Sysdig)
• Monitor for anomalous behavior
• Set up alerts for security events
• Regular security assessments

Supply Chain Security

Secure your CI/CD pipeline:

• Verify image provenance
• Implement admission controllers
• Use policy engines (OPA, Kyverno)
• Scan infrastructure as code

Conclusion

Kubernetes security is a multi-layered challenge that requires attention to detail and continuous vigilance. By implementing these best practices, you can significantly improve your cluster’s security posture and reduce the risk of compromise.