Best WAF for Kubernetes
Protect your Kubernetes workloads with container-native WAF solutions. Compare Ingress Controller WAFs, sidecar deployments, and cloud-native security platforms for EKS, GKE, and AKS.
Kubernetes has fundamentally changed how we deploy applications, and it requires a fundamentally different approach to WAF protection. Traditional perimeter-based WAFs struggle with the dynamic nature of pods, services, and ephemeral workloads. You need security that speaks Kubernetes natively.
WAF options for Kubernetes fall into three categories: Ingress Controller-based WAFs that protect traffic at the cluster edge, sidecar or service mesh integrations that protect individual services, and cloud-native WAFs from AWS, Google, and Azure that integrate with managed Kubernetes offerings. The right choice depends on your cluster architecture, cloud provider, and security requirements.
This guide evaluates WAF solutions specifically designed for Kubernetes, from open-source options for self-managed clusters to enterprise solutions for production workloads on managed Kubernetes platforms.
Top WAF Providers for Kubernetes
F5 WAF for NGINX
Enterprise LeaderF5 NGINX App Protect with the NGINX Ingress Controller is the leading enterprise WAF for Kubernetes. It runs natively within your Ingress Controller pods, providing per-request protection with F5's threat intelligence and 7,500+ signatures. Declarative configuration via CRDs fits GitOps workflows perfectly.
Key Benefits:
- Native NGINX Ingress Controller integration
- Kubernetes CRDs for declarative config
- F5 threat intelligence with 7,500+ signatures
- Per-pod or per-Ingress protection policies
ModSecurity Open Source WAF
Open Source ChoiceModSecurity can be deployed via the NGINX or HAProxy Ingress Controllers, providing free, battle-tested WAF protection for Kubernetes clusters. The OWASP Core Rule Set offers comprehensive coverage, and the open-source nature means no per-pod licensing costs—critical for large clusters.
Key Benefits:
- Free with no per-pod licensing
- OWASP CRS for comprehensive protection
- Works with NGINX and HAProxy Ingress
- Community-maintained Helm charts
Wallarm API Security Platform
API SecurityWallarm provides a cloud-native WAAP platform with Kubernetes-native deployment options including sidecar injection and Ingress Controller integration. For clusters running API-heavy microservices, Wallarm's API discovery and protection capabilities address threats that traditional WAFs miss.
Key Benefits:
- Sidecar and Ingress deployment options
- API discovery across services
- Free tier (500K requests)
- Integrated security testing (DAST)
AWS Web Application Firewall
Best for EKSFor Amazon EKS clusters, AWS WAF integrates natively with the AWS Load Balancer Controller. Protect your Kubernetes services exposed via ALB Ingress with managed rule groups and pay-per-request pricing that scales with your cluster.
Key Benefits:
- Native AWS ALB Ingress integration
- Managed rule groups included
- Pay-per-request pricing
- CloudWatch logging and metrics
Google Cloud Armor
Best for GKEGoogle Cloud Armor provides WAF and DDoS protection for GKE clusters using the GKE Gateway Controller or Ingress. ML-based adaptive protection and integration with Google's global network make it the natural choice for GKE deployments.
Key Benefits:
- Native GKE Ingress/Gateway integration
- ML-powered adaptive protection
- Google global network for DDoS
- Preconfigured WAF rules
BunkerWeb Open Source WAF
Modern Open SourceBunkerWeb can be deployed as a Kubernetes Ingress Controller or standalone reverse proxy, providing free WAF protection with a user-friendly web UI. For teams wanting ModSecurity-level protection without the configuration complexity, BunkerWeb offers a modern, accessible alternative.
Key Benefits:
- Kubernetes Ingress Controller mode
- Web UI for configuration
- ModSecurity + OWASP CRS included
- Docker and Helm deployment
What to Look For in a WAF for Kubernetes
Critical factors for selecting a Kubernetes WAF:
- Ingress Controller Integration - Does the WAF work with your Ingress Controller (NGINX, Traefik, HAProxy, cloud-native)? Or does it provide its own Ingress implementation?
- Deployment Model - Ingress-level protection covers all services behind the Ingress. Sidecar deployment protects individual pods but adds resource overhead per pod.
- CRD-Based Configuration - Kubernetes-native configuration via Custom Resource Definitions enables GitOps workflows and infrastructure-as-code.
- Per-Pod Licensing - Enterprise WAFs may charge per pod or instance. In large clusters with hundreds of pods, this can become expensive. Consider open-source alternatives for cost control.
- Horizontal Pod Autoscaling - Your WAF must scale with your application. Ensure it supports HPA and doesn't become a bottleneck during traffic spikes.
- Service Mesh Integration - If you use Istio, Linkerd, or another service mesh, check how the WAF integrates. Some WAFs work at the Ingress level only; others can integrate with mesh sidecars.
- Observability - WAF logs and metrics should integrate with your existing Kubernetes observability stack (Prometheus, Grafana, Elasticsearch, cloud-native logging).
Kubernetes Considerations
Kubernetes-specific WAF deployment considerations:
- Ingress vs Gateway API - The Gateway API is now GA and offers more flexibility than traditional Ingress resources. Check if your WAF supports Gateway API for future-proofing your configuration.
- Network Policies - WAF at the Ingress level complements but doesn't replace Kubernetes Network Policies for east-west traffic protection.
- Pod Security Standards - Ensure your WAF pods can run under your Pod Security Standards. Some WAFs require privileged containers or host networking.
- Resource Requests and Limits - WAF processing consumes CPU and memory. Set appropriate resource requests/limits to prevent node resource exhaustion.
- Multi-Tenancy - In multi-tenant clusters, consider whether WAF rules should be namespace-scoped or cluster-wide. CRD-based WAFs often support namespace isolation.
- Cloud Provider WAF Integration - Managed Kubernetes services (EKS, GKE, AKS) can integrate with their respective cloud WAFs at the load balancer level, outside the cluster.
- Secrets Management - If your WAF requires API keys or certificates, use Kubernetes Secrets or external secrets managers rather than ConfigMaps.
Frequently Asked Questions
Should I use a WAF at the Ingress level or as sidecars?
Ingress-level WAF is simpler and protects all traffic entering the cluster through that Ingress. Sidecar deployment (one WAF per pod) provides more granular protection and can protect east-west traffic between services, but adds resource overhead and complexity. Most teams start with Ingress-level WAF and add sidecar protection for high-security services if needed.
How do I protect traffic between services (east-west)?
Ingress WAFs only protect north-south traffic entering the cluster. For east-west protection, consider a service mesh with security policies (Istio, Linkerd), sidecar-deployed WAFs, or network policies. Many attacks originate from compromised pods, making east-west security increasingly important.
Can I use ModSecurity with the NGINX Ingress Controller?
Yes, the kubernetes/ingress-nginx controller supports ModSecurity as an optional module. Enable it via Helm values or ConfigMap, then configure rules via annotations or ConfigMap. This provides free, production-grade WAF protection for your Kubernetes Ingress.
What's the performance impact of WAF on Kubernetes?
WAF adds latency to every request—typically 1-10ms depending on rule complexity. For Ingress-level WAF, this overhead is per-request entering the cluster. Plan for additional CPU and memory in your Ingress Controller pods. Monitor response times after enabling WAF and tune rules if needed.
How do I handle WAF for multiple namespaces or teams?
Use CRD-based WAFs that support namespace-scoped policies. This allows each team to manage their own WAF rules for their namespace while cluster admins maintain global policies. NGINX App Protect and some ModSecurity Helm deployments support this pattern.
Should I use my cloud provider's WAF or a Kubernetes-native solution?
Cloud WAFs (AWS WAF, Cloud Armor, Azure WAF) operate at the load balancer level outside your cluster, providing DDoS protection and managed rules. Kubernetes-native WAFs run inside the cluster with better visibility into pod and service context. For comprehensive protection, use both—cloud WAF at the edge, Kubernetes WAF at the Ingress.