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Installing Docker

Learn to install Docker Engine on Linux, macOS and Windows.

Installing Docker

There are two ways to install Docker:

  • Linux: Docker Engine is installed directly. The official script is the fastest way; then add your user to the docker group to stop typing sudo for every command.
  • Windows and macOS: Docker Desktop is installed; it runs a lightweight Linux virtual machine inside.
curl -fsSL https://get.docker.com | sh
sudo usermod -aG docker $USER     # takes effect after logging out and in

Verifying the installation

Two checks are done after installing: that the client and daemon respond (docker version) and that a container can really run (docker run hello-world). A "permission denied ... docker.sock" error shows the user isn't in the docker group.

$ docker ps
permission denied while trying to connect to the Docker daemon socket
$ sudo usermod -aG docker $USER
$ newgrp docker      # activates the group in this session

Practice Installing on Linux

Write the command installing Docker with the official script, then the command adding the current user to the docker group.

Starter code

terminal
# buraya yaz

Sample solution

terminal
curl -fsSL https://get.docker.com | sh
sudo usermod -aG docker $USER

Expected output

# Executing docker install script
+ sh -c 'docker version'
Client: Docker Engine - Community

Questions and answers

Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.

1 How do Linux containers run on Windows and macOS?

  • They don't run
  • In a lightweight Linux virtual machine inside Docker Desktop Correct answer
  • Directly on the Windows kernel
  • In the browser

Explanation: A container shares the host kernel; a Linux container needs a Linux kernel.

2 Add the user to the docker group.

Question 
sudo usermod -aG ____ $USER
Answer 
sudo usermod -aG docker $USER

Explanation: Users in the docker group can access the daemon socket.

3 Match.

Term Meaning
get.docker.com Linux install script
Docker Desktop Windows/macOS installation
docker grubu No sudo needed
docker.sock Daemon socket

All lessons in Beginner

1 What is Docker?

  1. What is Docker?
  2. Containers and virtual machines
  3. Images and containers
  4. Docker architecture
  5. Use cases
  6. Summary - What is Docker

2 Installation and first commands

  1. Installing Docker
  2. docker version
  3. docker info
  4. The hello-world container
  5. Docker Desktop
  6. Summary - Installation

3 First container

  1. docker run basics
  2. Running in the background
  3. docker ps
  4. docker stop and rm
  5. docker logs
  6. Summary - First container

4 Dockerfile basics

  1. What is a Dockerfile?
  2. The FROM instruction
  3. The RUN instruction
  4. COPY and ADD
  5. CMD and ENTRYPOINT
  6. Summary - Dockerfile

5 Build and images

  1. docker build
  2. Tagging images
  3. Build context
  4. Layers and cache
  5. .dockerignore
  6. Summary - Build

6 docker run options

  1. Interactive mode
  2. Naming containers
  3. Restart policy
  4. Working directory
  5. Switching users
  6. Summary - docker run

7 Image management

  1. docker images
  2. docker rmi
  3. docker pull
  4. docker push
  5. docker tag
  6. Summary - Image management

8 Port mapping

  1. The port concept
  2. The -p flag
  3. Multiple ports
  4. Random ports
  5. IP binding
  6. Summary - Port mapping

9 Volumes and data

  1. Data persistence
  2. Named volumes
  3. The -v flag
  4. Bind mounts
  5. Volume management
  6. Summary - Volumes

10 Environment variables

  1. The -e flag
  2. The ENV instruction
  3. The ARG instruction
  4. env-file
  5. The WORKDIR instruction
  6. Summary - Environment

11 Project: docker-compose

  1. Compose design
  2. Service definition
  3. Database service
  4. Volume and network
  5. Putting it together - compose

12 Docker Hub and registry

  1. What is Docker Hub?
  2. docker login
  3. Searching images
  4. Official images
  5. Private registry
  6. Summary - Registry

13 Network basics

  1. Network drivers
  2. docker network ls
  3. Bridge network
  4. Container connectivity
  5. Publishing ports
  6. Summary - Network

14 Beginner final

  1. Challenge - Dockerfile
  2. Challenge - Build and run
  3. Challenge - Volume
  4. Challenge - Compose
  5. Challenge - Beginner project