Implementing Policy as Code in Kubernetes With OPA Gatekeeper

Managing a Kubernetes cluster at scale requires more than just standard Role-Based Access Control (RBAC). To maintain strict security, enforce organizational compliance, and implement FinOps best practices, platform teams need a reliable way to inspect and validate the configuration of resources allowed into the cluster. This is where Open Policy Agent (OPA) and OPA Gatekeeper come in: the industry-standard policy engine that integrates directly with the Kubernetes API to provide dynamic, customizable admission control and auditing capabilities.

In this lab, you will install OPA Gatekeeper and configure custom policy logic using the Rego language. You will then deploy Constraints to actively block non-compliant Kubernetes resources in real-time and use Gatekeeper's background auditing to identify pre-existing policy violations.

Learning Objectives

Upon completion of this advanced-level lab, you will be able to:

• Install and configure OPA Gatekeeper in a Kubernetes cluster
• Define a Gatekeeper Constraint Template using Rego
• Create and test a Gatekeeper Constraint based on the defined Constraint Template
• Audit existing resources in the cluster for compliance with Gatekeeper policies

Intended Audience

• Open Policy Agent (OPA) and Gatekeeper users
• Kubernetes admins and operators
• Application developers and DevOps engineers
• Certified Kubernetes Security Specialist (CKS) examinees

Prerequisites

To get the most out of this lab, you should have a basic understanding the following:

• Kubernetes Admission Controllers
• Kubernetes Custom Resource Definitions (CRDs)

The following content fulfills the prerequisites for this lab:

• Improving Kubernetes Security With Admission Controllers
• Using Kubernetes Custom Resource Definitions (CRDs)