As Kubernetes continues to grow in popularity as the go-to platform for managing containerized applications, the need for a robust and scalable policy engine has become increasingly apparent. This is where Kyverno comes in. Kyverno is an open-source policy engine for Kubernetes that helps to enforce policies related to security, compliance, automation, and best practices. Kyverno Policies are managed as Kubernetes resources and no new language is required to write policies. This allows using familiar tools such as kubectl, git, and kustomize to deploy and manage policies.
Kyverno was initially released in 2019 by Nirmata, a provider of Kubernetes policy management and governance platform. Since then, it has gained traction among Kubernetes users, especially those looking for a simpler way to manage policies in their Kubernetes environments.
One of the most significant advantages of Kyverno is its flexibility. It supports a wide range of policy types, from simple ones like enforcing container resource limits to more complex ones that require custom logic. Kyverno was built ground up for Kubernetes and as a result, it understands various Kubernetes constructs such as namespace, pods, labels, annotations, etc. Kyverno policies can be defined at the namespace or cluster level, making it easy to manage policies across a large Kubernetes environment. Policies are defined in YAML, making it easy to integrate them into your existing configuration management tools.
Some examples of how Kyverno is used are:
- Enforcing pod security policies: Kyverno can help to ensure that all pods running in your Kubernetes environment comply with your organization’s security policies. For example, you could create a policy that mandates the use of non-root users in pods or requires the use of specific security contexts.
- Enforcing resource limits: Kyverno can help to prevent pods from consuming too many resources, which can lead to performance issues or even cluster failure. You could create a policy that limits CPU or memory usage for all pods or for pods running in specific namespaces.
- Enforcing naming conventions and labels: Kyverno can help to ensure that all resources created in your Kubernetes environment follow your organization’s naming conventions. For example, you could create a policy that mandates the use of a specific prefix or label for all resources.
- Ensuring namespace isolation: Kyverno can also generate Kubernetes resources making it an ideal choice to enable advanced use cases for Namespace-as-a-service. For example, whenever a new namespace is created, Kyverno can generate default quotas, limits, roles, role bindings, network policy, etc.
Kyverno is also highly extensible, with a growing library of custom policies available in its community. This means that you can easily find pre-built policies to meet your specific needs or create custom policies to fit your environment’s requirements.
Here are some useful links to learn more about Kyverno: