Complete Kubernetes Course - From BEGINNER to PRO

Introduction

This tutorial provides a comprehensive guide to deploying applications using Kubernetes, focusing on various tools and techniques that enhance the developer experience and operational efficiency. By following this guide, you'll learn how to build, deploy, and manage applications in a Kubernetes environment, as well as explore CI/CD practices and GitOps methodologies.

Chapter 1: Introduction to Kubernetes

• Kubernetes is a powerful platform for automating the deployment, scaling, and management of containerized applications.
• It is essential for software engineers looking to enhance their DevOps skills.
• The course covers fundamental concepts and practical applications, culminating in deploying a representative demo application.

Chapter 2: History and Motivation

• Kubernetes emerged from the need to efficiently manage containerized applications across clusters.
• Understanding the evolution from on-premises deployments to cloud-native architecture helps appreciate Kubernetes's design.
• Key benefits of Kubernetes include automated scheduling, scaling, and self-healing capabilities.

Chapter 3: Technology Overview

• Familiarize yourself with key terms:
  • Cluster: A set of nodes (machines) running Kubernetes.
  • Node: An individual machine in a cluster.
  • Control Plane: Manages the cluster’s state and lifecycle.
  • Data Plane: Hosts the applications running in containers.
• Understand core components like the API server, etcd (the key-value store), and controllers responsible for maintaining the desired state.

Chapter 4: Installation and Setup

• Set up your local development environment and Kubernetes clusters.
• Install Docker Desktop and Devbox as prerequisites.
• Use Kind (Kubernetes in Docker) or managed services like GKE (Google Kubernetes Engine) for cluster creation.
• Create a local Kind cluster with the following command:

  kind create cluster
  

Chapter 5: Built-in Kubernetes Resources

• Explore key Kubernetes resources:
  • Namespaces: Organize resources within a cluster.
  • Pods: The smallest deployable units representing a running process in a container.
  • Deployments: Manage the deployment of Pods.
  • Services: Expose applications running on Pods to the network.
• Use kubectl commands to create and manage these resources:

  kubectl create namespace my-namespace
  kubectl apply -f deployment.yaml
  kubectl expose deployment my-deployment --type=LoadBalancer --port=80
  

Chapter 6: Helm for Package Management

• Helm is a package manager for Kubernetes, making it easier to deploy applications.
• Install Helm and use it to manage your Kubernetes applications with charts.
• Create a Helm chart with the following command:

  helm create my-chart
  

• Deploy using Helm:

  helm install my-release my-chart
  

Chapter 7: Deploying the Demo Application

• Deploy a representative demo application using the Kubernetes resources and Helm.
• Define all necessary resources in YAML files and use kubectl apply or Helm to deploy.
• Ensure that all components, such as the database and backend services, are functioning correctly.

Chapter 8: Continuous Integration and Delivery

• Use GitHub Actions to automate the CI/CD pipeline for your Kubernetes applications.
• Create workflows to build and push container images automatically upon code changes.
• Implement GitOps with tools like Kluctl to maintain synchronization between your Git repository and Kubernetes cluster.

Chapter 9: Managing Secrets

• Utilize the External Secrets Operator to manage sensitive data securely.
• Store secrets in a cloud provider's secret manager and reference them in Kubernetes without exposing sensitive information in your repository.
• Set up an external secret resource:

  apiVersion: external-secrets.io/v1alpha1
  kind: ExternalSecret
  metadata:
    name: my-secret
  spec:
    backendType: gcpSecretsManager
    data:
      - key: my-secret-key
        name: my-k8s-secret
  

Chapter 10: Debugging Applications in Kubernetes

• Use tools like kubectl logs, kubectl describe, and kubectl exec to debug applications.
• Implement K9s for a CLI-based UI to navigate your Kubernetes resources more easily.
• Follow a systematic approach to identify and resolve issues in your deployments.

Chapter 11: Upgrading Clusters and Nodes

• Regularly update your Kubernetes clusters to maintain security and access new features.
• Use tools like kubectl upgrade to manage the upgrade process safely.
• Consider using blue-green deployments or creating new node pools to minimize downtime during upgrades.

Chapter 12: Extending the Kubernetes API

• Learn about custom resources and operators to extend Kubernetes functionality.
• Use tools like Cloud Native PG to manage PostgreSQL databases with custom resources in Kubernetes.
• Define custom resource definitions (CRDs) to create and manage your resources effectively.

Conclusion

This tutorial provides a solid foundation for deploying and managing applications in Kubernetes. Key takeaways include understanding Kubernetes architecture, using Helm for package management, implementing CI/CD pipelines, and managing secrets securely. As you continue your Kubernetes journey, consider exploring advanced topics such as networking, resource optimization, and building custom operators to enhance your expertise and improve your application deployments.