Kubernetes Networking Overview

 

Pod Networking

Kubernetes Pods share the same network namespace, allowing them to communicate with each other via localhost.

Each Pod is assigned a unique IP address to enable communication across different nodes.

Service Networking

Services provide stable access points to Pods. Some common types include:

1. ClusterIP: Internal access within the cluster.
2. NodePort: Exposes services on a port on each node for external access.
3. LoadBalancer: Exposes services externally with a load balancer.

Ingress Networking

Ingress controls external access to services based on HTTP/HTTPS rules. Ingress controllers manage routing traffic to the correct services within the cluster.

Network Policies

Network policies define rules for communication between Pods and external resources. This allows for fine-grained control over network traffic within the cluster.

Container Network Interface (CNI)

The CNI is a standard for defining networking plugins used by Kubernetes. These plugins help manage network interfaces and assign IP addresses.

Networking Plugins

Kubernetes relies on networking plugins to handle traffic and name resolution:

• Kube-Proxy: Manages network rules and routes traffic to services.
• CoreDNS: Resolves DNS queries for Kubernetes services and Pods.