In the ever-evolving world of Kubernetes, ensuring security, compliance, and operational best practices is more critical than ever. One key mechanism for enforcing these controls is through admission controllers, which act as “gatekeepers” – inspecting and validating resources before they’re admitted into the cluster.

While OPA/Gatekeeper has long been a go-to solution for policy enforcement in Kubernetes, Kyverno has rapidly gained popularity as a powerful, Kubernetes-native alternative. Designed specifically for Kubernetes users by Nirmata, Kyverno offers a simpler, more intuitive approach to Kubernetes policy management.

At Nirmata, we’ve worked with several customers to help them migrate to Kyverno. Based on their experiences, here are the top 10 reasons why DevOps users prefer Kyverno over other admission controllers.

 

1.  Simplified Policy Definition with YAML

Kyverno uses YAML for policy definitions – the same format as Kubernetes manifests. This makes writing and understanding policies feel natural for Kubernetes users. In contrast, Gatekeeper uses Rego, a purpose-built language that introduces a steep learning curve.

“Writing policies in Gatekeeper was quite difficult… Kyverno felt like working with familiar Kubernetes selectors.”

 

2.  Kubernetes-Native by Design

Kyverno was built from the ground up for Kubernetes. It operates seamlessly as a Kubernetes admission controller, with deep integration into the Kubernetes ecosystem. Gatekeeper, while adapted for Kubernetes, originated as a general-purpose policy engine.

Kyverno’s Kubernetes-native approach translates to simpler setup, fewer components, and smoother operations.

 

3.  Powerful and Intuitive Mutation

Both tools now support mutation, but Kyverno’s implementation is widely considered more user-friendly. Whether it’s adding labels or enforcing resource limits, Kyverno makes mutations straightforward using YAML-based patches.

Gatekeeper’s “Assign” feature is more complex and can be harder to work with in practice.

 

4.  Built-in Resource Generation

Kyverno can generate Kubernetes resources automatically based on policy definitions – like creating NetworkPolicies or default ConfigMaps. This is a game-changer for enforcing compliance and security out-of-the-box.

Gatekeeper lacks built-in resource generation, making Kyverno the stronger choice for proactive configuration.

 

5.  Apply Policies to Existing Resources

Kyverno supports dynamic enforcement on existing resources – not just at admission time. This means you can update and apply policies retroactively to deployed resources.

Gatekeeper, in contrast, primarily focuses on admission-time validation and doesn’t natively support this.

 

6.  Extensive Policy Library

Kyverno offers a rich library of pre-defined policies, covering everything from Pod Security Standards (PSS) to best practices for Kubernetes configurations. This gives users a head start and reduces time spent authoring new policies.

Gatekeeper provides a framework but lacks a curated, Kubernetes-focused policy library at the same scale.

 

7.  Granular Policy Targeting

Using match and exclude rules in YAML, Kyverno enables fine-grained control over where and how policies are applied – based on labels, annotations, kinds, namespaces, and more.

This mirrors Kubernetes’ own selector mechanisms and makes policy application more predictable and flexible.

 

8.  Integrated Policy Exceptions

Kyverno supports built-in exception handling, allowing you to define specific resources or conditions where certain policies should not apply. This is essential for managing edge cases without disabling enforcement entirely.

Gatekeeper does not natively support policy exceptions, requiring custom logic or external tools.

 

9.  Seamless Testing and Simulation

Kyverno includes tools for testing and simulating policies before rolling them out. You can validate how a policy behaves against sample resources to catch issues early.

While Gatekeeper has tools like Gator, Kyverno’s built-in testing is more tightly integrated into the policy development workflow.

 

10. Vibrant, Kubernetes-Focused Community

Kyverno has a rapidly growing open-source community focused specifically on Kubernetes use cases. Regular updates, strong documentation, and community support make Kyverno an evolving and well-supported tool.

OPA/Gatekeeper also has an active community, but Kyverno’s Kubernetes-centric momentum is a big draw for platform teams.

 

Beyond the Basics: Advanced Capabilities

Kyverno continues to differentiate itself in the Kubernetes policy management arena with advanced features not natively available in Gatekeeper:

• Cleanup Policies: Kyverno automatically removes resources based on defined criteria—ideal for ephemeral workloads or cleanup after testing.
• Image Verification: Ensure OCI-compliant supply chain security, verify image signatures, and perform registry lookups—all natively supported in Kyverno.

These capabilities make Kyverno a comprehensive Kubernetes solution for both security and operational governance.

 

Conclusion

Both Kyverno and OPA/Gatekeeper are capable tools for managing Kubernetes policies. But if you’re looking for a solution that is easy to learn, Kubernetes-native, and packed with powerful features out of the box, Kyverno is hard to beat.

From intuitive YAML policies to built-in mutation, generation, and exception handling—Kyverno empowers platform and security teams to implement policies confidently across Kubernetes environments.

Want to learn more or see Kyverno in action? Request a demo and explore how you can elevate Kubernetes governance in your organization today. Have a question about what you’ve just read? Reach out to us, and we’ll get back to you promptly.

 

References

• Kubernetes policy comparison: Kyverno vs OPA/Gatekeeper
• Why did we transition from Gatekeeper to Kyverno for Kubernetes Policy Management
• Why I prefer Kyverno over Gatekeeper for native Kubernetes Policy Management
• Meet Kyverno for Open Source Security, Compliance, and Governance