How do I enforce policy-as-code for Linkerd using OPA and Conftest?

To enforce policy-as-code for Linkerd using Open Policy Agent (OPA) and Conftest, you'll want to define your policies in Rego, the policy language for OPA, and then use Conftest to test your Kubernetes manifests and Linkerd configurations against these policies. This setup can help ensure that your deployments adhere to company policies and security best practices.

Example Policy for Linkerd

The following example demonstrates how to create a simple policy that checks if the Linkerd proxy injection annotation is present in your Kubernetes Deployment manifests.

Using Conftest to Test Policies

After you define your policy, you can use Conftest to test your Kubernetes manifests against the policy. Here’s an example command that demonstrates how to run Conftest with your policy.

Conftest will parse the Kubernetes manifest file and evaluate it against the provided policy, letting you know if it passes or fails the tests.