Kubernetes Network Policies and Licensing Models

The cluster hums, but traffic is a threat until you control it. Kubernetes Network Policies give you that control. They define how pods communicate with each other and with the outside world. Without a policy, any pod can talk to any other. With a policy, you decide exactly who talks to who, on what ports, and using which protocols.

Network Policies in Kubernetes are implemented by the CNI plugin. Popular CNIs like Calico, Cilium, and Weave Net interpret policy rules and enforce them in the data plane. Kubernetes itself only provides the API and the model. The enforcement is the responsibility of the networking layer.

From a licensing perspective, it's important to separate the abstract specification from the concrete implementation. The Kubernetes API is open source under the Apache 2.0 license. This means the Network Policy resource definitions are free to use, modify, and distribute without licensing fees. However, the actual CNI that enforces policies may use a different licensing model. Calico is Apache 2.0 with enterprise features under proprietary terms. Cilium is also Apache 2.0, with premium support and enterprise add-ons. Other CNIs may follow GPL or commercial models.

When you plan your cluster security model, you need to consider both the technical behavior and the licensing terms. Free-tier open source plugins are suitable for many deployments, but enterprise environments often require advanced features like network flow visibility, encryption, or fine-grained rule management. These may be gated by commercial licenses or subscription plans.

A strategic approach is to evaluate the Kubernetes Network Policies Licensing Model before deployment. Match the policy features you need with a CNI whose license aligns with your legal and budget requirements. Pay attention to dual licensing schemes. Some vendors offer the core under an open license and premium features under a paid one. Ignoring this can lead to compliance risks or unexpected costs.

Your security posture depends on explicit, consistent rules. Your legal posture depends on knowing who owns the code that runs those rules. Before you scale, know both.

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