Gateway Ingress

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Table of Contents

• What Is Kubernetes Ingress?
• NGINX Ingress Controller Architecture
• AWS Load Balancer Controller
• Alternative Ingress Controllers & Service Meshes
• AWS Lattice: Gateway API Implementation
• Comparison of Traffic Management Options
• References

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What Is Kubernetes Ingress?

• Limited API extensibility for multi-team environments
• Controller-specific annotations for advanced L7 features
• One-to-one mapping between Ingress and external load balancers (in some providers)

• Role-based resource split: Gateways, Listeners, Routes
• Fine-grained control for teams and operators
• Extended protocol support beyond HTTP(S)

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NGINX Ingress Controller Architecture

# Example Service and Ingress
apiVersion: v1
kind: Service
metadata:
  name: myapp-service
spec:
  type: ClusterIP
  ports:
    - port: 5000
      targetPort: 5000
  selector:
    app: myapp

---
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: myapp-ingress
spec:
  rules:
    - host: myapp.example.com
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: myapp-service
                port:
                  number: 5000

1. Each ClusterIP Service is backed by a NodePort (e.g., 30000).
2. The NGINX Ingress controller Pod (via DaemonSet/Deployment) exposes ports 80/443 on every node.
3. An external Load Balancer forwards HTTP(S) traffic to node ports.
4. NGINX inspects the Host header and proxies to the correct Service.

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AWS Load Balancer Controller

• Define a standard Kubernetes Ingress.
• The controller reads L7 rules and creates an ALB with listener rules.
• The ALB routes traffic directly to your Service endpoints.

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Alternative Ingress Controllers & Service Meshes

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AWS Lattice: Gateway API Implementation

• Creates an external Load Balancer on your behalf.
• Routes cross-account or cross-service traffic (e.g., Kubernetes → AWS Lambda).
• Simplifies rule management at the AWS control plane.

• Cross-service routing (EC2, Lambda, ECS)
• Managed control plane without self-hosted proxies

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Comparison of Traffic Management Options

1. Gateway API supersedes Ingress with a stable, extensible L7 routing framework.
2. Ingress controllers (NGINX, Envoy-based, AWS ALB Controller) offer host-based routing without per-service load balancers.
3. Service meshes and AWS Lattice provide alternative north-south solutions—choose based on features, flexibility, and operational model.

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References

• Kubernetes Ingress: https://kubernetes.io/docs/concepts/services-networking/ingress/
• Gateway API: https://gateway-api.sigs.k8s.io/
• AWS Load Balancer Controller: https://github.com/kubernetes-sigs/aws-load-balancer-controller
• Istio: https://istio.io/
• Linkerd: https://linkerd.io/
• AWS Lattice: https://docs.aws.amazon.com/lattice/latest/ug/what-is-aws-lattice.html