Docker for Beginners Course Notes

Introduction

• Instructor: Moonshot 100, DevOps and Cloud Trainer at Code Cloud
• Course focus: Learn Docker through lectures, animations, illustrations, and hands-on labs.

Course Objectives

• Understand Containers and Docker
• Running Docker Containers
• Building Docker Images
• Networking in Docker
• Using Docker Compose
• Understanding Docker Registry
• Deploying a Private Registry
• In-depth understanding of Docker operations
• Introduction to Container Orchestration (Docker Swarm and Kubernetes)

Hands-On Labs

• Access to real labs in the browser, no personal setup required.
• Includes terminal access and quizzes to validate learning.
• Labs allow instant feedback and challenges.

Why Use Docker?

• Problem with environment compatibility ("Matrix from Hell"):
  • Issues arise with compatibility between services, libraries, and OS.
  • Difficulty onboarding new developers with environment setup.
• Solution: Docker allows running isolated environments (containers) with separate dependencies on the same VM.

What Are Containers?

• Definition: Isolated environments sharing the same OS kernel.
• Containers are not new; Docker uses LXC containers.
• Benefits: Simplified setup, lower resource overhead compared to VMs.

Operating Systems and Docker

• Docker leverages shared kernel architecture.
• Containers vs. Virtual Machines:
  • Containers are lightweight, utilizing fewer resources compared to VMs.
  • VMs need separate OS installations, while containers share the host OS kernel.

Working with Docker

• Docker Commands:
  • docker run: Run a container from an image.
  • docker ps: List running containers.
  • docker stop: Stop a running container.
  • docker rm: Remove a container.
  • docker images: List images on the host.
  • docker rmi: Remove an image.
  • docker pull: Download an image without running it.
• Images vs. Containers:
  • Images are templates for containers; containers are running instances of these images.

Environment Configuration in Docker

• Environment Variables: Set with -e option during docker run command.
• Persisting Data: Use volumes to store data outside of containers.
  • Bind mounts vs. volumes: Bind mounts link a host directory, volumes are managed Docker directories.

Docker Registry

• Definition: Central repository for Docker images.
• Public and Private Registries:
  • Default is Docker Hub.
  • Can create private registries for internal use.

Docker Engine Architecture

• Components:
  • Docker Daemon: Manages Docker objects.
  • REST API: Interface for communication with the daemon.
  • Docker CLI: Command-line interface.

Docker on Windows and Mac

• Windows Options:
  • Docker Toolbox: For older systems using VirtualBox.
  • Docker Desktop: Uses Hyper-V for better integration.
• Mac Options: Similar to Windows with Docker Toolbox or Docker Desktop.

Container Orchestration

• Definition: Tools that manage containers in production environments (e.g., scaling, failover).
• Examples of Orchestration Tools:
  • Docker Swarm: Easy to set up, suitable for small applications.
  • Kubernetes: More advanced features for large-scale applications.

Summary and Conclusion

• Docker simplifies application deployment and management through containers.
• Next steps: More advanced topics and orchestration with Docker Swarm and Kubernetes.