Ultimate Docker Course Notes

Course Overview

• Journey from basics of Docker to advanced concepts
• Practical course that takes you from zero to hero
• By the end of the course, proficiency in Docker for software development workflow
• Initial project: simple application to understand Docker basics
• Full-stack application deployment (front end, back end, database)

Prerequisites

• No prior Docker knowledge needed
• At least 3 months programming experience recommended
• Familiarity with concepts: front-end, back-end, API, database
• Basic Git commands (clone, commit, push, pull)

Learning Strategy

• Active Participation: Take notes during lessons
• After each lesson, experiment with learned commands and concepts
• Key takeaways from every session

Introduction to Docker

• What is Docker?

  • A platform for building, running, and shipping applications consistently across environments.
  • Eliminates deployment issues related to variations between local and target environments.
  • All app dependencies packaged together, ensuring consistent setups.

• Benefits of Docker:

  • Simplifies app setup for new team members.
  • Isolated environments (containers) allow coexistence of applications with different dependencies.
  • Easy removal of applications and their dependencies, keeping the development machine clean.

Employers' Demand

• Increasing demand for Docker skills among employers, particularly for software and DevOps engineers.

Containers vs. Virtual Machines (VMs)

• Virtual Machines (VMs):
  • Abstraction of physical hardware using hypervisors (e.g., VMware, VirtualBox).
  • Slow to start and resource-intensive due to running full operating systems.
• Containers:
  • Lightweight; share the host OS kernel, leading to faster startup.
  • Can run hundreds of containers on a single host without resource contention.

Docker Architecture

• Client-Server Architecture: Utilizes a client to communicate with a server (Docker Engine) via RESTful API.
• Containers: Unique processes with their own file system that run isolated from each other.
• Overview of OS compatibility:
  • Linux: Only Linux containers can run.
  • Windows: Supports both Windows and Linux containers.
  • macOS: Runs Linux containers in a lightweight VM.

Installing Docker

• Installation Steps:
  • Latest version available at Docker website.
  • Verify system compatibility before installation.
  • Docker Desktop for Windows/Mac, Docker Engine for Linux.
  • Important for Windows: Enable Hyper-V and Containers features.
• Verify Installation:
  • Use the command docker version in the terminal to check if Docker is running.

Development Workflow with Docker

• Dockerizing an application: Introduces a Dockerfile containing packaging instructions.
  • Dockerfile elements include:
    • Base image (e.g., node, alpine)
    • Copy application files into the container
    • Execute commands needed to run the application.
• Docker Registry: Docker Hub serves as a storage for Docker images (similar to GitHub for code).
• Running Applications:
  • Commands to build and run containers using Docker images.

Basic Linux Commands for Docker Users

• Importance of Linux knowledge for troubleshooting and productivity with Docker.
• Overview of Linux distributions with Ubuntu as the primary focus in the course.
• Basic commands in Ubuntu:
  • pwd: Show current directory.
  • ls: List files and directories.
  • cd: Change directory.
  • mkdir: Create a directory.
  • touch: Create a new file.
  • rm: Remove files or directories recursively.

File and Text Manipulation

• Text editors in Linux: Using nano to create and edit files.
• Viewing file content with commands:
  • cat: View file content.
  • more: Scroll through file output.
  • less: Enhanced scrolling capabilities.
  • head and tail: View the beginning or end of files respectively.
• Redirection: Using > to redirect output to files and < for input.

Course Sign-off

• Emphasizes the importance of additional learning and practicing Linux commands.
• Encouragement to explore additional resources, especially for those serious about mastering Docker.