Nov 22, 20232 min read

Services and Networking in Kubernetes - Day 53

Welcome back to our #90DaysOfDevOps journey! Today, we'll be discussing about Services and Networking in Kubernetes, vital components that enable seamless communication and external access to your applications.

Understanding Kubernetes Services

What are Kubernetes Services?

In Kubernetes, a Service is an abstraction that defines a logical set of Pods and a policy by which to access them. It provides a stable endpoint (IP and port) to access a set of Pods, regardless of their individual IPs. Services enable inter-pod communication within the cluster.

Types of Services

ClusterIP: This is the default service type. It exposes the Service on an internal IP in the cluster. It's accessible only within the cluster.
NodePort: Exposes the Service on a static port on each Node's IP. It allows external access to the Service.
LoadBalancer: Exposes the Service externally using a cloud provider's load balancer. Useful when your application is hosted on a cloud platform.

Ingress Controllers for External Access

While Services handle internal communication, Ingress Controllers manage external access to Services. An Ingress is a collection of rules that allow inbound connections to reach Services. It acts as an API object that manages external access to services within a cluster, typically providing HTTP and HTTPS routing.

Here's a simple example of an Ingress manifest:

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

This Ingress rule directs traffic from my-domain.com to a Service named my-service on port 80.

In Practice: Services and Ingress Controllers

Create a ClusterIP Service: Define a Service manifest and apply it using kubectl apply -f service.yaml. This creates an internal service accessible within the cluster.
Access a NodePort Service: Create a NodePort Service, allowing external access. Use kubectl apply -f nodeport-service.yaml. Access the service via http://Node_IP:NodePort.
Deploy an Ingress Controller: Deploy an Ingress Controller like Nginx or Traefik using their manifests. Once deployed, define Ingress rules to manage external access to your services.
Test External Access: Access your services externally using the specified domain and paths.

Services and Ingress Controllers are the linchpin of networking in Kubernetes, enabling seamless communication between pods and managing external access to your applications. Mastering these concepts is crucial for designing robust and scalable Kubernetes architectures.

With this, let's wrap this post here.

Thank you for reading!

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