Docker Tutorials

Docker Tutorials Roadmap

Section 1: Introduction to Containerization and Docker

  • What is Containerization?
    • Understanding the problem solved by containers (dependency hell, "works on my machine").
    • Comparison with Virtual Machines (VMs) - resource usage, isolation levels, startup time.
    • Key concepts: Images, Containers, Docker Engine.
  • What is Docker?
    • A popular platform for building, sharing, and running containerized applications.
    • Docker ecosystem: Docker Engine, Docker Desktop, Docker Hub, Docker Compose, Docker Swarm, Kubernetes (brief mention).
  • Setting up the Docker Environment:
    • Installing Docker Desktop (for Windows and macOS).
    • Installing Docker Engine (for Linux).
    • Verifying the installation (docker --version, docker info).
    • Understanding the Docker daemon and client.
  • Running Your First Container:
    • Using the docker run command.
    • Understanding the process: Pulling an image, creating a container, starting the container.
    • Running simple containers (e.g., hello-world, ubuntu, alpine).
  • Basic Docker Commands:
    • docker ps (list running containers).
    • docker ps -a (list all containers, including stopped).
    • docker images (list downloaded images).
    • docker start container_id/name (start a stopped container).
    • docker stop container_id/name (stop a running container).
    • docker rm container_id/name (remove a container).
    • docker rmi image_id/name (remove an image).
    • docker pull image_name[:tag] (download an image).
    • docker exec container_id/name command (execute a command inside a running container).
    • docker logs container_id/name (view container logs).

Section 2: Docker Images

  • What is a Docker Image?
    • A read-only template with instructions for creating a Docker container.
    • Layered filesystem concept.
    • Base images and layers.
  • What is a Dockerfile?
    • A text file that contains a set of instructions for building a Docker image.
    • Common Dockerfile instructions: FROM, RUN, CMD, ENTRYPOINT, COPY, ADD, WORKDIR, ENV, EXPOSE, VOLUME.
  • Writing Your First Dockerfile:
    • Building a simple image (e.g., a Python application, a static HTML site).
    • Using the docker build command.
    • Tagging images (docker build -t name[:tag] .).
  • Understanding Image Layers:
    • How layers are created by Dockerfile instructions.
    • Caching layers for faster builds.
    • Optimizing Dockerfile for smaller images and faster builds (order of instructions, multi-stage builds).
  • Image Tagging and Versioning:
    • Understanding image tags (latest, specific versions).
    • Best practices for tagging.
  • Pushing and Pulling Images from Registries:
    • What is a Docker Registry? (Docker Hub, private registries).
    • Logging in to a registry (docker login).
    • Pushing an image (docker push image_name[:tag]).
    • Pulling an image (docker pull image_name[:tag]).

Section 3: Docker Containers

  • What is a Docker Container?
    • A runnable instance of a Docker image.
    • Containers are isolated processes running on the host OS.
    • Containers are ephemeral by default.
  • Container Lifecycle:
    • Created, Running, Paused, Stopped, Exited.
  • Managing Containers:
    • Starting, stopping, restarting, removing containers.
    • Attaching to container processes (docker attach).
    • Executing commands inside containers (docker exec).
    • Viewing container logs (docker logs).
    • Inspecting containers (docker inspect).
  • Container Networking:
    • Understanding Docker network types (bridge, host, none, overlay).
    • Mapping ports (-p host_port:container_port).
    • Container linking (deprecated).
    • Using user-defined networks.
    • Connecting containers to networks.
  • Container Storage (Volumes):
    • Understanding the need for persistent storage.
    • Types of volumes:
      • Bind mounts (mounting host directories).
      • Volume mounts (managed by Docker).
      • tmpfs mounts (in-memory storage).
    • Creating and managing volumes (docker volume create, docker volume ls, docker volume rm).
    • Using volumes in Dockerfiles and docker run.

Section 4: Docker Compose (for Multi-Container Applications)

  • What is Docker Compose?
    • A tool for defining and running multi-container Docker applications.
    • Uses a YAML file (docker-compose.yml) to configure application services.
  • Installing Docker Compose.
  • Writing Your First docker-compose.yml File:
    • Defining services, images, build context, ports, volumes, networks.
  • Docker Compose Commands:
    • docker-compose up (build, create, start services).
    • docker-compose up --build (force rebuild images).
    • docker-compose down (stop and remove containers, networks, volumes).
    • docker-compose ps (list services).
    • docker-compose logs (view service logs).
    • docker-compose exec service_name command (execute a command in a service container).
    • docker-compose build (build service images).
  • Defining Dependencies between Services.
  • Using Networks and Volumes with Docker Compose.

Section 5: Docker Orchestration (Introduction)

  • What is Container Orchestration?
    • Managing and automating the deployment, scaling, networking, and availability of containerized applications.
    • Why orchestration is needed in production.
  • Introduction to Docker Swarm:
    • Docker's built-in orchestration tool.
    • Concepts: Nodes, Managers, Workers, Services, Tasks, Stacks.
    • Initializing a Swarm.
    • Deploying a stack using a Compose file (v3 format).
    • Scaling services.
    • Rolling updates.
  • Introduction to Kubernetes (Optional but highly recommended):
    • The de facto standard for container orchestration.
    • Brief overview of core Kubernetes concepts (Pods, Deployments, Services, Namespaces, Nodes, Clusters).
    • Understanding why Kubernetes is often chosen for complex production environments.
    • (Note: A full Kubernetes roadmap would be separate).

Section 6: Advanced Docker Concepts and Best Practices

  • Dockerfile Best Practices:
    • Keeping images small (multi-stage builds, using smaller base images like Alpine).
    • Reducing layers.
    • Ordering instructions for effective caching.
    • Using .dockerignore.
    • Running applications as non-root users.
  • Container Security:
    • Running containers with minimal privileges.
    • Scanning images for vulnerabilities.
    • Docker Content Trust.
  • Docker Networking (Advanced):
    • Custom network configurations.
    • DNS in Docker.
  • Docker Storage (Advanced):
    • Volume drivers.
    • Data persistence strategies.
  • Docker Registries (Advanced):
    • Setting up a private registry.
    • Registry authentication and security.
  • Troubleshooting Docker Issues:
    • Debugging containers and images.
    • Common errors and solutions.
  • Integrating Docker with CI/CD Pipelines.
  • Monitoring Docker Containers.

Section 7: Real-World Examples and Projects

  • Containerizing different types of applications:
    • Web applications (Python/Django, Node.js, Java, etc.).
    • Databases (PostgreSQL, MySQL, MongoDB).
    • Caching systems (Redis, Memcached).
    • Message queues (RabbitMQ, Kafka).
  • Building a multi-container application using Docker Compose (e.g., a web app with a database).
  • Deploying a Docker Swarm service.

Section 8: What's Next?

  • Deep dive into Kubernetes.
  • Exploring cloud-native technologies.
  • Advanced monitoring and logging solutions.
  • Security best practices for containerized environments.