Gatekeeper 3.13: Policy Enforcement Evolution and Performance

Introduction

Gatekeeper 3.13, released on March 5, 2023, is most relevant if you’re hardening clusters without turning every deploy into a support ticket. The real value is in rollout safety: tighter controls with fewer false positives, clearer policy outcomes, and smoother day-2 response when something is blocked.

Mutation Improvements

• Mutation capabilities enable modifying resources during admission to enforce policies.
• Mutation testing improvements simplify developing and validating mutation policies.
• Conflict resolution handles mutation conflicts more intelligently.
• Performance optimizations reduce latency for mutation operations.

Template Library Expansion

1. Pre-built templates provide more policy templates for common use cases.
2. Template improvements enable more flexible and expressive policy templates.
3. Community templates enable sharing and reuse of policy templates.
4. Template validation ensures templates are correct and safe.

Performance Enhancements

• Evaluation performance optimizations reduce latency for policy decisions.
• Caching improvements reduce redundant policy evaluations.
• Resource usage optimizations reduce CPU and memory footprint.
• Concurrent evaluation enables better handling of high-traffic scenarios.

Kubernetes Integration

• Admission control integration provides policy enforcement at resource creation and update time.
• Audit logging tracks all policy decisions and violations.
• Metrics expansion exposes detailed policy metrics for Prometheus.
• Operator improvements simplify Gatekeeper installation and management.

Getting Started

kubectl apply -f https://raw.githubusercontent.com/open-policy-agent/gatekeeper/release-3.13/deploy/gatekeeper.yaml

Create a ConstraintTemplate:

apiVersion: templates.gatekeeper.sh/v1beta1
kind: ConstraintTemplate
metadata:
  name: k8srequiredlabels
spec:
  crd:
    spec:
      names:
        kind: K8sRequiredLabels
      validation:
        openAPIV3Schema:
          type: object
          properties:
            labels:
              type: array
              items:
                type: string
  targets:
    - target: admission.k8s.gatekeeper.sh
      rego: |
        package k8srequiredlabels
        violation[{"msg": msg}] {
          required := input.parameters.labels
          provided := input.review.object.metadata.labels
          missing := required[_]
          not provided[missing]
          msg := sprintf("Missing required label: %v", [missing])
        }

Summary

Gatekeeper 3.13 provides teams with comprehensive policy enforcement capabilities using OPA for securing and standardizing Kubernetes deployments.