💡 Today I Learned

Lesson Plan for Mastering Containers, Docker, and Kubernetes

This lesson plan progresses from understanding basic concepts of containers, up to mastery of docker and kubernetes.

Phase 1: Understanding Containers

Goal: Grasp container fundamentals, benefits, and the role of Docker.

Phase 1 Topics

  1. What are Containers?

    • Introduction to containers and virtual machines
    • The role of containers in modern development and deployment
    • Benefits of containers (portability, isolation, efficiency)

  2. Getting Started with Docker:

    • Installing Docker
    • Basic Docker commands (docker run, docker pull, docker images, docker ps, docker exec, docker stop, etc.)
    • Exploring Docker Hub
    • Understanding Dockerfile and creating your first Docker image
    • Basic Dockerfile structure (FROM, RUN, CMD, COPY, EXPOSE)

  3. Networking and Volumes:

    • Docker container networking basics
    • Creating and using Docker volumes for persistent storage
    • Linking containers

  4. Hands-On Exercise:

    • Build a simple web server inside a Docker container (e.g., Nginx or Node.js)
    • Push an image to Docker Hub

Outcome

You should understand what containers are and be able to create, run, and share containerized applications.

Phase 2: Docker Deep Dive

Goal: Master Docker and its ecosystem for development and production use.

Phase 2 Topics

  1. Docker Compose:

    • Introduction to multi-container applications
    • Defining services in docker-compose.yml
    • Managing lifecycle (docker-compose up, docker-compose down)
    • Networking between services in Docker Compose

  2. Dockerfile Optimization:

    • Best practices for writing Dockerfiles (caching, layer ordering)
    • Multi-stage builds to reduce image size
    • Minimizing attack surface with lightweight base images

  3. Docker Networking:

    • Bridge network, host network, and overlay network
    • Service discovery and DNS in Docker networks
    • Container communication across multiple hosts

  4. Security in Docker:

    • Basic security practices (running containers as non-root, using official images)
    • Introduction to Docker Content Trust
    • Scanning Docker images for vulnerabilities (e.g., docker scan)

  5. Hands-On Exercise:

    • Build and orchestrate a multi-container application (e.g., a web app with a database) using Docker Compose
    • Optimize an existing Dockerfile and reduce its size

Phase 2 Outcome

You should be proficient in using Docker for complex projects and ready to use containers in production environments.

Phase 3: Introduction to Kubernetes (K8s)

Goal: Understand Kubernetes' architecture and basic use cases.

Phase 3 Topics

  1. Kubernetes Overview:

    • What is Kubernetes, and why use it?
    • Key concepts: Pods, Nodes, Clusters
    • Kubernetes architecture: Master and worker nodes, etcd, kube-apiserver

  2. Setting Up a Local Kubernetes Cluster:

    • Installing Minikube or using Docker Desktop with Kubernetes
    • Accessing the Kubernetes dashboard
    • Introduction to kubectl

  3. Basic Kubernetes Objects:

    • Pods, ReplicaSets, Deployments, Services
    • Creating, updating, and deleting resources with kubectl

  4. Hands-On Exercise:

    • Deploy a simple application in a Kubernetes cluster (e.g., a stateless web app)
    • Expose the application with a Service
    • Scale the application using kubectl scale

Phase 3 Outcome

You should be able to run a basic application on Kubernetes, using core concepts like Pods, Deployments, and Services.

Phase 4: Kubernetes Deep Dive

Goal: Gain proficiency in Kubernetes management and more advanced features.

Phase 4 Topics

  1. ConfigMaps, Secrets, and Volumes:

    • Managing configuration with ConfigMaps and Secrets
    • Storing data with Persistent Volumes (PVs) and Persistent Volume Claims (PVCs)

  2. Kubernetes Networking:

    • Cluster networking basics: Service types (ClusterIP, NodePort, LoadBalancer)
    • Ingress controllers and Ingress resources for routing

  3. Kubernetes Scheduling and Scaling:

    • Horizontal Pod Autoscaler (HPA)
    • Node affinity, taints, and tolerations for advanced scheduling

  4. Kubernetes Security:

    • Role-Based Access Control (RBAC)
    • Network Policies
    • Pod Security Policies (PSP)

  5. Deployments and StatefulSets:

    • Understanding the difference between Deployments and StatefulSets
    • Deploying stateful applications

  6. Hands-On Exercise:

    • Deploy a stateful service like a database with StatefulSets
    • Use ConfigMaps and Secrets to manage application configurations

Phase 4 Outcome

You should be comfortable managing Kubernetes clusters, including deployments, scaling, networking, and security features.

Phase 5: Advanced Kubernetes and CI/CD

Goal: Master advanced Kubernetes topics and integrate with CI/CD pipelines.

Phase 5 Topics

  1. Kubernetes Operators and Custom Resource Definitions (CRDs):

    • What are Operators?
    • Writing and deploying a simple Operator

  2. Monitoring and Logging in Kubernetes:

    • Set up logging with Fluentd or ELK (Elasticsearch, Logstash, Kibana)
    • Monitoring with Prometheus and Grafana

  3. Kubernetes in Production:

    • Best practices for Kubernetes in production environments
    • Kubernetes clusters in cloud platforms (AWS EKS, Google GKE, Azure AKS)

  4. CI/CD with Docker and Kubernetes:

    • Automating Docker image builds with Jenkins or GitLab CI
    • Deploying to Kubernetes from CI/CD pipelines
    • Rolling updates and Canary deployments

  5. Hands-On Exercise:

    • Set up CI/CD pipeline to build a Docker image and deploy it to Kubernetes automatically
    • Implement rolling updates

Phase 5 Outcome

You should have the knowledge and skills to work with Kubernetes in production environments and set up automated deployments.

Phase 6: Real-World Projects and Troubleshooting

Goal: Build practical, production-ready solutions and troubleshoot issues.

Phase 6 Topics

  1. Debugging and Troubleshooting:

    • Debugging Kubernetes deployments and Pods
    • Troubleshooting common Docker and Kubernetes issues (failed Pods, image pull issues, etc.)

  2. Real-World Project:

    • Design and implement a full-stack application with microservices architecture using Docker and Kubernetes
    • Set up CI/CD for automatic deployment and monitoring

Phase 6 Outcome

You should be able to tackle real-world container orchestration challenges and feel confident in managing large-scale applications in Docker and Kubernetes.

Additional Resources

See also