How to install Docker-CE on Ubuntu 22.04

Docker is a set of platform-as-a-service products that uses OS-level virtualization to deliver software in packages called containers. Containers are usually isolated from one another and bundled with their own software libraries and configuration files, they can communicate with each other through well-defined channels.

Docker makes it possible to get more apps running on the same old servers and also makes it easy to package and ship programs. In this tutorial am going to show you how you can install Docker-CE on Ubuntu 20.04.

Related Articles

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• How to install Docker on Arch Linux
• How to install Docker-ce on Ubuntu 21.10
• How to install and configure Docker-CE on Ubuntu 20.04

Prerequisites

• Make sure you have a user with sudo privileges
• Have Ubuntu 22.04 server up and running
• Have basic knowledge about running commands on a shell

Install Docker-ce on Ubuntu 22.04

1. Update system repositories

Let’s begin by updating our system repositories to make them up to date.

sudo apt update && apt upgrade -y

When both updates and upgrades are complete, we can go ahead and uninstall old Docker versions.

2. Uninstall old versions of Docker

Old versions of Docker were called docker, docker.io or docker-engine. Uninstall them before installing the new one.

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

If they were not installed then you will see an output like this:

# output
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Package 'docker-engine' is not installed, so not removed
Package 'containerd' is not installed, so not removed
Package 'runc' is not installed, so not removed
Package 'docker' is not installed, so not removed
Package 'docker.io' is not installed, so not removed
The following packages were automatically installed and are no longer required:
  docker-ce-rootless-extras docker-scan-plugin libslirp0 pigz slirp4netns
Use 'sudo apt autoremove' to remove them.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

3. Installing Docker on Ubuntu 22.04

There are three methods we can install Docker,

• Install using the DEB repository
• Install from the packages
• Install using a convenient script

Install using .deb Repository

We are installing docker here for the first time, so we need to set up the Docker repository in our system.

To set up the repository first install required dependencies such as, ca-certificates, curl, GnuPG and lsb-release.

sudo apt install ca-certificates curl gnupg lsb-release

The output will be as follows:

Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
ca-certificates is already the newest version (20211016).
gnupg is already the newest version (2.2.27-3ubuntu2).
gnupg set to manually installed.
lsb-release is already the newest version (11.1.0ubuntu4).
lsb-release set to manually installed.
curl is already the newest version (7.81.0-1ubuntu1.1).
The following packages were automatically installed and are no longer required:
  docker-ce-rootless-extras docker-scan-plugin libslirp0 pigz slirp4netns
Use 'sudo apt autoremove' to remove them.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

Then the next step is to install GPG key to sign the docker images being installed.

curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /usr/share/keyrings/docker-archive-keyring.gpg

The next step is to set up a stable, nightly, or test repository depending on what you want to install.

echo \
  "deb [arch=$(dpkg --print-architecture) signed-by=/usr/share/keyrings/docker-archive-keyring.gpg] https://download.docker.com/linux/ubuntu \
  $(lsb_release -cs) stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null

Lastly, let’s install the Docker engine. To check the available versions we can use the apt-cache madison docker-ce command.

$ sudo apt-cache madison docker-ce
docker-ce | 5:20.10.15~3-0~ubuntu-jammy | https://download.docker.com/linux/ubuntu jammy/stable amd64 Packages
 docker-ce | 5:20.10.14~3-0~ubuntu-jammy | https://download.docker.com/linux/ubuntu jammy/stable amd64 Packages
 docker-ce | 5:20.10.13~3-0~ubuntu-jammy | https://download.docker.com/linux/ubuntu jammy/stable amd64 Packages

Install Docker-Engine

Before we can install the Docker engine let’s update our repositories one more time.

$ sudo apt update
$ sudo apt-get install docker-ce docker-ce-cli containerd.io docker-compose-plugin

4. Enable Docker

We need to enable docker-ce to start on reboot, in order to avoid starting every time you boot your machine.

sudo systemctl enable docker

5. Start Docker service

You are supposed to start the docker service to run containerd environment. To start, use the following command.

sudo systemctl start docker

Lastly, we can check the status of docker to see if it is running.

6. Check the status of Docker

Check if Docker is running with the following command on your terminal.

$ sudo systemctl status docker
● docker.service - Docker Application Container Engine
     Loaded: loaded (/lib/systemd/system/docker.service; enabled; vendor preset>
     Active: active (running) since Mon 2022-05-09 09:45:15 EAT; 8min ago
TriggeredBy: ● docker.socket
       Docs: https://docs.docker.com
   Main PID: 9636 (dockerd)
      Tasks: 10
     Memory: 30.5M
        CPU: 477ms
     CGroup: /system.slice/docker.service
             └─9636 /usr/bin/dockerd -H fd:// --containerd=/run/containerd/cont>

May 09 09:45:14 zx-pc dockerd[9636]: time="2022-05-09T09:45:14.783146457+03:00">
May 09 09:45:14 zx-pc dockerd[9636]: time="2022-05-09T09:45:14.783171530+03:00">

If you got status active, then your docker service is running as expected, if not probably you haven’t started the service.

7. Test Docker

Let’s test our docker to see if it is running. Test using hello-world container. This will pull hello-world image from docker hub

$ sudo docker run hello-world
Unable to find image 'hello-world:latest' locally
latest: Pulling from library/hello-world
2db29710123e: Pull complete 
Digest: sha256:10d7d58d5ebd2a652f4d93fdd86da8f265f5318c6a73cc5b6a9798ff6d2b2e67
Status: Downloaded newer image for hello-world:latest

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

To generate this message, Docker took the following steps:
 1. The Docker client contacted the Docker daemon.
 2. The Docker daemon pulled the "hello-world" image from the Docker Hub.
    (amd64)
 3. The Docker daemon created a new container from that image which runs the
    executable that produces the output you are currently reading.
 4. The Docker daemon streamed that output to the Docker client, which sent it
    to your terminal.

To try something more ambitious, you can run an Ubuntu container with:
 $ docker run -it ubuntu bash

Share images, automate workflows, and more with a free Docker ID:
 https://hub.docker.com/

For more examples and ideas, visit:
 https://docs.docker.com/get-started/

We can try to install ubuntu like this docker run -it ubuntu bash

$ sudo docker run -it ubuntu bash
Unable to find image 'ubuntu:latest' locally
latest: Pulling from library/ubuntu
125a6e411906: Pull complete 
Digest: sha256:26c68657ccce2cb0a31b330cb0be2b5e108d467f641c62e13ab40cbec258c68d
Status: Downloaded newer image for ubuntu:latest
[email protected]:/# 

You now have running ubuntu inside a docker container.

Install Docker using a convenient script

Using this method is not recommended for the production environment. Use it only when doing some tests.

To download the script run the following:

curl -fsSL https://get.docker.com -o get-docker.sh

Then execute the script with this command:

sudo sh get-docker.sh

Install Docker from the Package

To install Docker from the package, go to docker distros page and chose Ubuntu distribution, then choose if you want stable, nightly or test version.

Download the package

wget https://download.docker.com/linux/ubuntu/dists/jammy/stable/Contents-amd64

Run the installation using the following command:

sudo dpkg -i /path/to/package.deb

Uninstalling Docker

Whenever you want to uninstall docker from your machine, use the following command to completely remove the installation.

sudo apt-get purge docker-ce docker-ce-cli containerd.io docker-compose-plugin

Then you need to delete all the images, volumes, and containers with these commands

$ sudo rm -rf /var/lib/docker
$ sudo rm -rf /var/lib/containerd

Conclusion

From here you can see our Docker is running as expected, Learn other docker commands to be well conversant with docker. Docker Documentation has a tone of information.