Section Introduction

Welcome to the Google Cloud Networking module. When architecting your applications, you must determine which services they interact with and where those services reside—whether inside your cluster or in external systems.

In this lesson, we’ll cover three key topics:

1. Exposing Pods using Kubernetes Services for internal and external communication
2. Provisioning Load Balancers to distribute traffic across your cluster
3. Configuring Ingress resources to route and manage incoming requests

Exposing Applications Internally with Kubernetes Services

A Service in Kubernetes abstracts a set of Pods and provides a stable network endpoint. This allows applications to discover and communicate with each other without tracking individual Pod IPs.

apiVersion: v1
kind: Service
metadata:
  name: my-app-service
spec:
  type: ClusterIP
  selector:
    app: my-app
  ports:
    - port: 80
      targetPort: 8080

Leveraging Load Balancers for External Traffic

To expose your Service to the internet, set type: LoadBalancer. Google Cloud will automatically provision a network load balancer and assign a public IP.

1. Create Service: Define a Service of type LoadBalancer.
2. Provision LB: GKE allocates a public IP and configures forwarding rules.
3. Distribute Traffic: Incoming requests are balanced across healthy Pods.

kubectl apply -f loadbalancer-service.yaml
kubectl get service my-app-service

Routing Traffic with Ingress

An Ingress resource defines HTTP(S) routing rules to Services. It provides host- and path-based routing and integrates with Google Cloud HTTP(S) Load Balancers for advanced features like SSL termination and cloud CDN.

Sample Ingress Manifest

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: my-app-ingress
spec:
  rules:
    - host: example.com
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: my-app-service
                port:
                  number: 80

Links and References

• Google Kubernetes Engine (GKE)
• Kubernetes Services Documentation
• Kubernetes Ingress Documentation
• Google Cloud Load Balancing