Tag: Kubernetes security in production

Description: Explore a production-tested, security-first approach to implementing Kubernetes Pod Security Standards, ensuring robust DevSecOps practices.

Introduction to Kubernetes Pod Security Standards

It was a quiet Thursday afternoon—or so I thought. I was reviewing logs when I noticed something odd: a privileged container running in our production cluster. Turns out, someone had deployed it with overly permissive settings during a rushed release. That single misstep could have been catastrophic if exploited. This is why Kubernetes Pod Security Standards (PSS) are non-negotiable in production environments.

Pod Security Standards are Kubernetes’ way of enforcing security policies at the pod level. They define what pods can and cannot do, ensuring your cluster isn’t a playground for attackers. But here’s the catch: implementing PSS correctly requires more than just flipping a switch. It demands thoughtful planning, testing, and integration into your DevSecOps workflows.

Understanding the Three Pod Security Modes

Kubernetes Pod Security Standards offer three modes: Privileged, Baseline, and Restricted. Each mode serves a different purpose, and understanding them is key to securing your cluster.

• Privileged: The “anything goes” mode. Pods have unrestricted access to host resources, which is great for debugging but a nightmare for security. Avoid this in production.
• Baseline: The middle ground. It restricts dangerous capabilities like host networking but allows common configurations. Suitable for most workloads.
• Restricted: The gold standard for security. It enforces strict policies, preventing privilege escalation, host access, and unsafe configurations. Ideal for sensitive workloads.

Implementing Pod Security Standards in Production

Applying PSS policies in a real-world Kubernetes cluster can be challenging, but it’s worth the effort. Here’s how to do it:

Step 1: Define Your Policies

Start by defining Pod Security Standards in YAML files. For example:

apiVersion: policy/v1
kind: PodSecurityPolicy
metadata:
  name: restricted
spec:
  privileged: false
  allowPrivilegeEscalation: false
  requiredDropCapabilities:
    - ALL
  volumes:
    - 'configMap'
    - 'emptyDir'
    - 'secret'
This policy enforces the Restricted mode, ensuring pods can’t escalate privileges or access the host.
Step 2: Apply Policies to Namespaces
Assign policies to namespaces based on workload sensitivity. For example:
kubectl label namespace production pod-security.kubernetes.io/enforce=restricted

⚠️ Gotcha: Don’t forget to test policies in staging before applying them to production. Misconfigured policies can break workloads.

Step 3: Monitor Policy Violations
Use tools like kubectl or Gatekeeper to monitor compliance:
kubectl get pods --namespace production --field-selector=status.phase!=Running

💡 Pro Tip: Automate compliance checks using Open Policy Agent (OPA). It integrates seamlessly with Kubernetes and CI/CD pipelines.

Integrating PSS with DevSecOps Workflows
To make PSS enforcement scalable, integrate it into your DevSecOps workflows. Here’s how:
Automate PSS Enforcement
Use CI/CD pipelines to validate policies before deployment. For example:
# Example CI/CD pipeline step
steps:
  - name: Validate Pod Security Policies
    run: |
      kubectl apply --dry-run=client -f pod-security-policy.yaml
Audit Policies Regularly
Set up periodic audits to ensure compliance. Tools like Kubernetes Audit Logs can help.
Lessons from Production: Real-World Insights
Over the years, I’ve seen teams struggle with PSS adoption. Here are some lessons learned:

Start small: Apply policies to non-critical namespaces first.
Communicate: Educate developers on why PSS matters.
Iterate: Review and refine policies regularly.


🔐 Security Note: Never assume your policies are perfect. Threats evolve, and so should your security standards.

Conclusion and Next Steps
Here’s what to remember:

Pod Security Standards are critical for securing Kubernetes clusters.
Restricted mode should be your default for production workloads.
Integrate PSS enforcement into your DevSecOps workflows for scalability.

Want to dive deeper? Check out Kubernetes Pod Security Standards documentation or explore tools like OPA and Gatekeeper.
Have a story about implementing PSS in production? Share it with me on Twitter or drop a comment below. Next week, we’ll explore Kubernetes network policies—because securing pods is only half the battle.