Course Introduction¶

This article introduces a hands-on Kubernetes Networking course featuring browser-based labs and covers essential networking concepts and tools.

Excel in Kubernetes networking through hands-on labs and troubleshooting drills tailored for new SREs. Cover CNIs, services, Ingress, and security to ensure robust and secure container communication.

Unlock the full potential of Kubernetes with our comprehensive Kubernetes Networking course, designed for DevOps engineers, IT professionals, and system administrators. This course simplifies the complexities of Kubernetes networking, offering in-depth insights and hands-on experience with modern container networking. Immerse yourself in multiple hands-on labs designed to simulate real-world scenarios, putting you in the shoes of a recently hired SRE at Company X.

Section 1 - Networking Overview Start with an introduction to Kubernetes networking, exploring its architecture and crucial role in container orchestration. Dive into Kubernetes Networking Models, comparing Host-Only, Overlay, and Network Policies, coupled with best practices to ensure robust and secure networking.

Section 2 - CNIs Grasp the fundamentals of Container Networking Interfaces (CNI) like Calico, Flannel, and Weave, and learn to configure and manage Cilium as the selected CNI for this course. Enhance your understanding of network add-ons such as CoreDNS and kube-proxy. Master pod networking, intra-pod communication, and IP addressing along with network namespaces and policies to control and secure pod communications.

Section 3 - Services Understand the intricacies of Kubernetes Services, including Cluster IP, NodePort, LoadBalancer, and ExternalName Services. Learn about Endpoints and Endpoint Slices, their creation, and practical examples. Explore DNS-based service discovery mechanisms that enable seamless service communication within the cluster. Finally, delve into common networking issues and their resolution, along with troubleshooting tools and techniques.

Section 4 - Ingress Get introduced to Ingress Controllers and Ingress Resources, focusing on setting up and managing the Traefik Ingress Controller. Discover how to use ExternalDNS to configure exposed services and Ingresses with DNS Providers. Advance your knowledge with Service Mesh for multi-cluster deployments and cross-cluster communication using Cilium Cluster Mesh.

Section 5 - Security Focus on security best practices, considering encryption, authentication, and authorization for network traffic to ensure a secure Kubernetes environment. Learn to leverage tools like Cert-manager and Let’s Encrypt for secure operations. Implement advanced security features such as Cilium Network Policies and mTLS, and utilize Hubble to troubleshoot network flows for optimal performance.

What You’ll Learn¶

By the end of this course, you’ll have a thorough understanding of Kubernetes networking—from basic pod connectivity to advanced security policies and multi-cluster topologies.

Module	Topics Covered
1. Kubernetes Networking Architecture	Host-only vs. Pod-to-Pod communication, Overlay networks, CoreDNS, Network Policies
2. Container Network Interfaces (CNIs)	Installing and configuring Calico, Flannel, Weave; deep dive into Cilium features and eBPF
3. Kubernetes Services	ClusterIP, NodePort, LoadBalancer, ExternalName; Endpoints & EndpointSlices; DNS-based service discovery
4. Ingress Controllers & Resources	Deploying Traefik Ingress; ExternalDNS integration; Intro to Service Mesh and multi-cluster routing
5. Network Security	mTLS encryption & authentication; cert-manager with Let’s Encrypt; Cilium Network Policies; Hubble CLI troubleshooting

Links and References¶

Kubernetes Networking Concepts – https://kubernetes.io/docs/concepts/cluster-administration/networking/
Cilium Documentation – https://docs.cilium.io/
Hubble (Cilium Observability) – https://github.com/cilium/hubble
cert-manager – https://cert-manager.io/
Traefik Ingress Controller – https://doc.traefik.io/traefik/

Kubernetes Networking¶

Course Introduction (docs/kubernetes/networkAdvanced/index.md)
The Kubernetes Network
- Demo Kubernetes Network Model

Container Network Interface CNI¶

Introduction to Container Network Interface CNI
Cilium Overview
Installing Cilium Overview
Installing Cilium and Hubble CLI
- Demo Installing Cilium on Kubernetes
Internal Kubernetes Communication Overview
Pod to Pod Communication
Network Policies Overview
- Demo Network Policies

Kubernetes Services¶

Services Overview
Service Discovery and DNS Overview
- Demo Service Discovery and DNS
Service Types
- Demo Service Types
Endpoints and Endpoint Slices Overview
- Demo Endpoints and Endpoint Slices
Troubleshooting Internal Networking
- Demo Troubleshooting Internal Networking