Docker Fundamentals

Docker Daemon

• Runs on the host operating system
• Responsible for running containers and managing Docker services
• Communicates with other daemons
• Offers various Docker objects such as images, containers, networking, and storage

Docker Architecture

• Follows Client-Server architecture
• Comprises three main components: Docker Client, Docker Host, and Docker Registry

Docker Client

• Uses commands and REST APIs to communicate with the Docker Daemon (Server)
• Sends docker commands to the Docker Daemon
• Can communicate with more than one Docker Daemon
• Uses Command Line Interface (CLI) to run commands such as:
  • docker build
  • docker pull
  • docker run

Docker Host

• Provides an environment to execute and run applications
• Contains the Docker Daemon, images, containers, networks, and storage

Docker Registry

• Manages and stores Docker images
• Has two types: Public Registry (Docker Hub) and Private Registry (for sharing images within an enterprise)

Docker Objects

• Docker Images
  • Read-only binary templates used to create Docker Containers
  • Use private and public container registries to share container images
  • Metadata is used to describe the container's abilities
• Docker Containers
  • Structural units of Docker that hold the entire package needed to run an application
  • Require very little resources
  • Image is a template, and the container is a copy of that template
• Docker Networking
  • Allows communication between isolated packages
  • Offers various network drivers
• Docker Storage
  • Used to store data on the container
  • Offers various storage options