Implementing Policy as Code with Open Policy Agent

When to Use

• When enforcing organizational security policies across Kubernetes clusters programmatically
• When requiring admission control that blocks non-compliant resources from being created
• When implementing policy governance that can be version-controlled, tested, and audited
• When standardizing security rules across multiple clusters and environments
• When needing a flexible policy engine that extends beyond Kubernetes to APIs and CI/CD

Do not use for vulnerability scanning (use Trivy/Checkov), for runtime threat detection (use Falco), or for network policy enforcement (use Kubernetes NetworkPolicy or Calico).

Prerequisites

• Kubernetes cluster with admin access for Gatekeeper installation
• Helm for Gatekeeper deployment
• OPA CLI or conftest for local policy testing
• Rego knowledge for policy authoring

Workflow

Step 1: Install OPA Gatekeeper

# Install Gatekeeper via Helm
helm repo add gatekeeper https://open-policy-agent.github.io/gatekeeper/charts
helm install gatekeeper gatekeeper/gatekeeper \
  --namespace gatekeeper-system --create-namespace \
  --set replicas=3 \
  --set audit.…