Installing Docker

Instructions for installing Docker on Linux systems based on Debian.

Requirements

Installation

1. Refresh the package index.

   sudo apt-get update
   

2. Remove any previous Docker packages.

   sudo apt-get remove docker docker-engine docker.io
   

3. Install the docker.io package from the official repositories.

   sudo apt-get install docker.io
   

Note: the installer creates a docker user group. Only users in that group can run Docker without superuser privileges.

4. Add your user to the docker group.

   sudo usermod -a -G docker $USER
   

5. Restart the session (or the system) so the new group membership takes effect.

   sudo reboot
   

Verification

Check the installed version.

docker --version

Docker version 18.09.1, build 4c52b90

Verify that the service is running.

sudo service docker status

● docker.service - Docker Application Container Engine
Loaded: loaded (/lib/systemd/system/docker.service; disabled; vendor preset: enabled)
Active: active (running) since Sat 2020-05-23 13:44:15 -04; 55s ago
    Docs: https://docs.docker.com
Main PID: 5821 (dockerd)
    Tasks: 14
CGroup: /system.slice/docker.service
            └─5821 /usr/bin/dockerd -H fd:// --containerd=/run/containerd/containerd.sock

...

Run the hello-world container to confirm the setup.

docker run hello-world

Unable to find image 'hello-world:latest' locally
latest: Pulling from library/hello-world
0e03bdcc26d7: Pull complete
Digest: sha256:6a65f928fb91fcfbc963f7aa6d57c8eeb426ad9a20c7ee045538ef34847f44f1
Status: Downloaded newer image for hello-world:latest

Hello from Docker!
This message shows that your installation appears to be working correctly.

...

Auto-start

Control whether the service starts automatically.

sudo systemctl enable docker

To disable auto-start:

sudo systemctl disable docker

References

• How To Install Docker On Ubuntu 18.04 Bionic Beaver