OPA Gatekeeper Kyverno Kubernetes Policy Engine – DevOps Course in Telugu

Author : sireesha r | Published On : 18 Feb 2026

In modern Kubernetes environments, managing deployments is not just about running containers. Security, compliance, governance, and standardization are equally important. As organizations scale, manual checks become impossible. 

In this DevOps Course in Telugu, we will explore how OPA Gatekeeper and Kyverno help enforce policies automatically inside Kubernetes clusters.

Why Kubernetes Needs Policy Enforcement

In a large organization, multiple teams deploy applications. Without policies:

• Developers may deploy containers as root

• Images may come from untrusted registries

• Resource limits may not be defined

• Privileged containers may be allowed

• Security best practices may be ignored

These misconfigurations can lead to:

• Security vulnerabilities

• Compliance violations

• Cluster instability

• Increased cloud costs

Kubernetes provides RBAC and admission controllers, but they are not enough for complex policy logic. That’s where policy engines come in.

What is OPA?

Open Policy Agent (OPA) is a general-purpose policy engine that allows you to define rules using a language called Rego.

OPA can be used across:

• Kubernetes

• APIs

• CI/CD pipelines

• Microservices authorization

In Kubernetes, OPA works through a project called Gatekeeper.

What is Gatekeeper?

Gatekeeper is a Kubernetes admission controller powered by OPA.

It allows DevOps teams to:

• Define custom policies

• Validate Kubernetes resources

• Block non-compliant deployments

• Audit existing resources

Gatekeeper works by intercepting Kubernetes API requests and checking them against defined policies before allowing them into the cluster.

Example Policies with Gatekeeper

Here are some common policies:

1. Disallow containers running as root

2. Require resource limits for CPU and memory

3. Allow images only from approved registries

4. Enforce specific labels on resources

5. Block privileged containers

For example, if a developer tries to deploy a pod without memory limits, Gatekeeper can reject the request automatically.

This ensures consistency and security across environments.

What is Kyverno?

Kyverno is a Kubernetes-native policy engine designed specifically for Kubernetes.

Unlike OPA, Kyverno uses YAML-based policies instead of Rego.

This makes it easier for Kubernetes administrators to write policies without learning a new language.

Kyverno can:

• Validate resources

• Mutate configurations

• Generate resources

• Verify container images

Its Kubernetes-native design makes it very intuitive.

Key Differences: Gatekeeper vs Kyverno

Both tools are powerful. The choice depends on team expertise and use cases.

Validation vs Mutation

Policy engines can do two types of enforcement:

1. Validation

Check whether resource meets policy.

Example:

• If no CPU limit → Reject deployment

2. Mutation

Automatically modify resource before creation.

Example:

• Add default resource limits

• Add required labels

• Inject security context

Kyverno is particularly strong in mutation use cases.

Real-World Use Cases

1. Security Hardening

Prevent:

• Privileged containers

• HostPath mounts

• Root user containers

2. Cost Optimization

Enforce:

• CPU/memory limits

• Resource quotas

• Namespace restrictions

3. Compliance

Ensure:

• Required labels (team, environment)

• Encryption annotations

• Approved container registries

4. Multi-Tenant Clusters

Restrict namespaces and permissions per team.

Policy as Code

Modern DevOps promotes “Policy as Code”.

This means:

• Policies stored in Git

• Version controlled

• Reviewed through pull requests

• Tested in CI/CD pipelines

Benefits:

• Transparency

• Auditability

• Standardization

• Automation

Policy enforcement becomes part of DevSecOps strategy.

Integration with CI/CD

OPA and Kyverno can also integrate into:

• CI pipelines

• GitOps workflows

• Pre-deployment checks

Before code reaches production, policy validation ensures compliance.

This prevents issues before they happen.

DevOps Course Learning Path (Telugu)

In a DevOps course covering OPA Gatekeeper and Kyverno, students should learn:

1. Kubernetes admission controllers

2. OPA architecture

3. Writing Rego policies

4. Installing Gatekeeper

5. Creating ConstraintTemplates

6. Writing Kyverno policies

7. Mutation and validation examples

8. Policy testing

9. Integrating with CI/CD

Hands-on labs should include:

• Blocking privileged pods

• Enforcing resource limits

• Automatically adding labels

• Verifying container images

Practical implementation builds real-world confidence.

Best Practices for Kubernetes Policy Enforcement

1. Start with audit mode before enforce mode

2. Test policies in staging environment

3. Keep policies simple and modular

4. Document policy intent clearly

5. Monitor rejected requests

6. Review policies regularly

Overly strict policies can slow down development if not implemented properly.

Balance security with productivity.

Why Policy Engines are Essential in DevOps

As Kubernetes adoption grows, so do risks. Manual review of YAML files is not scalable.

Policy engines provide:

• Automated governance

• Strong security controls

• Compliance enforcement

• Standardized deployments

• Reduced operational risk

Organizations moving towards DevSecOps must implement policy enforcement early in their cloud journey.

Conclusion

OPA Gatekeeper and Kyverno are powerful Kubernetes policy engines that help enforce security, governance, and compliance automatically.

Gatekeeper offers flexible policy logic using Rego, while Kyverno provides Kubernetes-native YAML-based policies that are easier to adopt.