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Kubernetes Network Policies as Infrastructure as Code

Andrios Robert

• 1 min read

Kubernetes Network Policies are the control mechanism that decides which pods can talk to each other and which cannot. They enforce traffic rules at the namespace and pod level. Without them, internal services are exposed, and any pod can send traffic to any other. With them, you can lock communication down to the exact flows your cluster needs.

Defining Network Policies manually through kubectl is possible, but it is brittle and hard to maintain. Infrastructure as Code (IaC) changes that. By declaring policies in YAML files stored in version control, you can track changes, apply them repeatedly, and integrate them into CI/CD pipelines. This makes networking in Kubernetes predictable and auditable.

A simple IaC workflow for Kubernetes Network Policies looks like this:

  1. Write policy manifests that specify ingress and egress rules for each workload.
  2. Commit them into a Git repository alongside other Kubernetes manifests.
  3. Use a deployment tool like kubectl apply, kustomize, or Helm to push changes automatically.
  4. Run tests to confirm that traffic flows match the defined rules.

Key elements to capture in your IaC for Network Policies:

  • Namespace scoping: Policies apply only within the namespace they are defined.
  • Selectors: Use podSelector and namespaceSelector to target exact workloads.
  • Ingress rules: Control incoming traffic sources explicitly.
  • Egress rules: Restrict outbound traffic destinations.
  • Default deny behavior: Combine multiple policies to block traffic by default, opening only what is required.

Automation is critical. Every cluster upgrade or deployment can shift network behavior. By keeping Network Policies in the same IaC system as your deployments, you ensure rules are applied consistently. This consistency prevents misconfigurations from leaving sensitive services exposed.

Kubernetes Network Policies as Infrastructure as Code give you fine-grained control, repeatable workflows, and better compliance posture. They are not optional in serious production environments.

See how it works in real time. Test Kubernetes Network Policies with IaC on hoop.dev and watch it live in minutes.