Kubernetes Crash Course

Introduction

• Presenter: Nana
• Overview: Introductory course to Kubernetes in one hour.
• Content:
  • Definition and need for Kubernetes.
  • Kubernetes architecture.
  • Main Kubernetes components.
  • Hands-on demo project.

What is Kubernetes?

• Definition: Open-source container orchestration framework developed by Google.
• Purpose: Manages applications composed of containers across various environments.
• Environments: Physical machines, virtual machines, cloud, hybrid.

Why Kubernetes?

• Challenges:
  • Rise of microservices increased container usage.
  • Managing numerous containers across environments is complex.
• Solutions Provided by Kubernetes:
  • High Availability: Ensures no downtime.
  • Scalability: Adjusts to load demands.
  • Disaster Recovery: Data backup and recovery mechanisms.

Kubernetes Architecture

• Cluster Components:
  • Master Node: Runs key processes:
    • API Server: Entry point for all communications.
    • Controller Manager: Manages cluster state.
    • Scheduler: Allocates resources for containers.
    • etcd: Key-value storage for current cluster state.
  • Worker Nodes:
    • Run application containers.
    • Kubelet: Facilitates communication among nodes.
• Networking:
  • Virtual network connects all nodes.

Kubernetes Components

• Pod: Smallest unit, abstraction over a container.
• Service: Provides stable IP for communication between pods.
• Ingress: Manages external access to services.
• ConfigMap: Stores non-sensitive configuration data.
• Secret: Stores sensitive data, encoded in base64.
• Volumes: Persistent data storage for containers.
• Deployment: Manages replicated stateless applications.
• StatefulSet: Manages stateful applications like databases.

Practical Setup

• MiniKube: Local Kubernetes cluster for testing.
• Kubectl: Command-line tool to interact with Kubernetes clusters.
• Hands-On Example:
  • Deploy MongoDB and a web application.
  • Use ConfigMap and Secret for configuration.
  • Web application accessible via browser using NodePort service.

Configuration Files

• Format: YAML or JSON.
• Structure:
  • Three parts: Metadata, Specification, Status.
• Example: Deployment and Service configuration.

Conclusion

• Additional Resources:
  • Complete Kubernetes Administrator Course.
  • Complete DevOps Educational Program.

Commands Summary

• kubectl get: List components.
• kubectl describe: Detailed component information.
• kubectl logs: View logs of a pod.
• minikube start: Start a local Kubernetes cluster.

Final Thoughts

• Kubernetes provides scalability, flexibility, and control over containerized applications.
• Practice with tools like MiniKube and Kubectl to enhance understanding.
• Explore further learning for deeper expertise in Kubernetes and DevOps.