Mục lục bài viết

Install Docker Engine on Ubuntu

To get started with Docker Engine on Ubuntu, make sure you
meet the prerequisites, and then follow the
installation steps.

Prerequisites

OS requirements

To install Docker Engine, you need the 64-bit version of one of these Ubuntu
versions:

Ubuntu Kinetic 22.10
Ubuntu Jammy 22.04 (LTS)
Ubuntu Focal 20.04 (LTS)
Ubuntu Bionic 18.04 (LTS)

Docker Engine is compatible with x86_64 (or amd64), armhf, arm64, and
s390x architectures.

Uninstall old versions

Older versions of Docker went by the names of docker, docker.io, or
docker-engine, you might also have installations of containerd or runc.
Uninstall any such older versions before attempting to install
a new version:

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

apt-get might report that you have none of these packages installed.

Images, containers, volumes, and networks stored in /var/lib/docker/ aren’t
automatically removed when you uninstall Docker. If you want to start with a
clean installation, and prefer to clean up any existing data, read the
uninstall Docker Engine section.

Installation methods

You can install Docker Engine in different ways, depending on your needs:

Docker Engine comes bundled with
Docker Desktop for Linux. This is
the easiest and quickest way to get started.
Set up and install Docker Engine from
Docker’s apt repository.
Install it manually and manage upgrades manually.
Use a convenience scripts. Only
recommended for testing and development environments.

Install using the apt repository

Before you install Docker Engine for the first time on a new host machine, you
need to set up the Docker repository. Afterward, you can install and update
Docker from the repository.

Set up the repository

Update the apt package index and install packages to allow apt to use a
repository over HTTPS:

$
 
sudo apt-get update

$
 
sudo 
apt-get install
 \
    ca-certificates \
    curl \
    gnupg

Add Docker’s official GPG key:

$
 
sudo install
 -m
 0755 -d /etc/apt/keyrings
$
 
curl -fsSL
 https://download.docker.com/linux/ubuntu/gpg | sudo 
gpg --dearmor
 -o /etc/apt/keyrings/docker.gpg
$
 
sudo chmod a+r /etc/apt/keyrings/docker.gpg

Use the following command to set up the repository:

$
 
echo
 \
  "deb [arch="
$(
dpkg --print-architecture
)
" signed-by=/etc/apt/keyrings/docker.gpg] https://download.docker.com/linux/ubuntu 
\

  "
$(
.
 /etc/os-release &&
 echo
 "
$VERSION_CODENAME
"
)
" stable"
 | \
  sudo tee
 /etc/apt/sources.list.d/docker.list > /dev/null

Install Docker Engine

Update the apt package index:
```
$
 
sudo apt-get update
```

Install Docker Engine, containerd, and Docker Compose.

Latest
Specific version

To install the latest version, run:

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

To install a specific version of Docker Engine, start by listing the available
versions in the repository:

#
 List the available versions:
$
 
apt-cache madison docker-ce | awk
 '{ print $3 }'

5:20.10.16~3-0~ubuntu-jammy
5:20.10.15~3-0~ubuntu-jammy
5:20.10.14~3-0~ubuntu-jammy
5:20.10.13~3-0~ubuntu-jammy

Select the desired version and install:

$
 
VERSION_STRING
=5:20.10.13~3-0~ubuntu-jammy
$
 
sudo 
apt-get install 
docker-ce=
$VERSION_STRING
 docker-ce-cli=
$VERSION_STRING containerd.io docker-buildx-plugin docker-compose-plugin

Verify that the Docker Engine installation is successful by running the
hello-world image:
```
$
 
sudo docker run hello-world
```
This command downloads a test image and runs it in a container. When the
container runs, it prints a confirmation message and exits.

You have now successfully installed and started Docker Engine.

Receiving errors when trying to run without root?

The docker user group exists but contains no users, which is why you’re required
to use sudo to run Docker commands. Continue to Linux post-install
to allow non-privileged users to run Docker commands and for other optional configuration steps.

Upgrade Docker Engine

To upgrade Docker Engine, follow the
installation instructions, choosing the new version
you want to install.

Install from a package

If you can’t use Docker’s apt repository to install Docker Engine, you can
download the deb file for your release and install it manually. You need to
download a new file each time you want to upgrade Docker Engine.

Go to https://download.docker.com/linux/ubuntu/dists/.
Select your Ubuntu version in the list.
Go to pool/stable/ and select the applicable architecture (amd64,
armhf, arm64, or s390x).
Download the following deb files for the Docker Engine, CLI, containerd,
and Docker Compose packages:
- containerd.io_<version>_<arch>.deb
- docker-ce_<version>_<arch>.deb
- docker-ce-cli_<version>_<arch>.deb
- docker-buildx-plugin_<version>_<arch>.deb
- docker-compose-plugin_<version>_<arch>.deb

Install the .deb packages. Update the paths in the following example to
where you downloaded the Docker packages.

$
 
sudo 
dpkg -i
 ./containerd.io_<version>_<arch
>
.deb \
  ./docker-ce_<version>_<arch
>
.deb \
  ./docker-ce-cli_<version>_<arch
>
.deb \
  ./docker-buildx-plugin_<version>_<arch
>
.deb \
  ./docker-compose-plugin_<version>_<arch
>.deb

The Docker daemon starts automatically.

Verify that the Docker Engine installation is successful by running the
hello-world image:
```
$
 
sudo service docker start
$
 
sudo docker run hello-world
```
This command downloads a test image and runs it in a container. When the
container runs, it prints a confirmation message and exits.

You have now successfully installed and started Docker Engine. The docker user
group exists but contains no users, which is why you’re required to use sudo
to run Docker commands. Read Linux post-install
to allow non-privileged users to run Docker commands and for other optional
configuration steps.

Upgrade Docker Engine

To upgrade Docker Engine, download the newer package files and repeat the
installation procedure, pointing to the new files.

Install using the convenience script

Docker provides a convenience script at
https://get.docker.com/ to install Docker into
development environments non-interactively. The convenience script isn’t
recommended for production environments, but it’s useful for creating a
provisioning script tailored to your needs. Also refer to the
install using the repository steps to learn
about installation steps to install using the package repository. The source code
for the script is open source, and you can find it in the
docker-install repository on GitHub.

Always examine scripts downloaded from the internet before running them locally.
Before installing, make yourself familiar with potential risks and limitations
of the convenience script:

The script requires root or sudo privileges to run.
The script attempts to detect your Linux distribution and version and
configure your package management system for you.
The script doesn’t allow you to customize most installation parameters.
The script installs dependencies and recommendations without asking for
confirmation. This may install a large number of packages, depending on the
current configuration of your host machine.
By default, the script installs the latest stable release of Docker,
containerd, and runc. When using this script to provision a machine, this may
result in unexpected major version upgrades of Docker. Always test upgrades in
a test environment before deploying to your production systems.
The script isn’t designed to upgrade an existing Docker installation. When
using the script to update an existing installation, dependencies may not be
updated to the expected version, resulting in outdated versions.

Tip: preview script steps before running

You can run the script with the --dry-run option to learn what steps the
script will run when invoked:
$
 
curl -fsSL
 https://get.docker.com -o get-docker.sh
$
 
sudo 
sh ./get-docker.sh --dry-run

This example downloads the script from
https://get.docker.com/ and runs it to install the
latest stable release of Docker on Linux:

$
 
curl -fsSL
 https://get.docker.com -o get-docker.sh
$
 
sudo sh get-docker.sh
Executing docker install script, commit: 7cae5f8b0decc17d6571f9f52eb840fbc13b2737
<...>

You have now successfully installed and started Docker Engine. The docker
service starts automatically on Debian based distributions. On RPM based
distributions, such as CentOS, Fedora, RHEL or SLES, you need to start it
manually using the appropriate systemctl or service command. As the message
indicates, non-root users can’t run Docker commands by default.

Use Docker as a non-privileged user, or install in rootless mode?

The installation script requires root or sudo privileges to install and
use Docker. If you want to grant non-root users access to Docker, refer to the
post-installation steps for Linux.
You can also install Docker without root privileges, or configured to run in
rootless mode. For instructions on running Docker in rootless mode, refer to
run the Docker daemon as a non-root user (rootless mode).

Install pre-releases

Docker also provides a convenience script at
https://test.docker.com/ to install pre-releases of
Docker on Linux. This script is equal to the script at get.docker.com, but
configures your package manager to use the test channel of the Docker package
repository. The test channel includes both stable and pre-releases (beta
versions, release-candidates) of Docker. Use this script to get early access to
new releases, and to evaluate them in a testing environment before they’re
released as stable.

To install the latest version of Docker on Linux from the test channel, run:

$
 
curl -fsSL
 https://test.docker.com -o test-docker.sh
$
 
sudo sh test-docker.sh

Upgrade Docker after using the convenience script

If you installed Docker using the convenience script, you should upgrade Docker
using your package manager directly. There’s no advantage to re-running the
convenience script. Re-running it can cause issues if it attempts to re-install
repositories which already exist on the host machine.

Uninstall Docker Engine

Uninstall the Docker Engine, CLI, containerd, and Docker Compose packages:

$
 
sudo apt-get purge docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin docker-ce-rootless-extras

Images, containers, volumes, or custom configuration files on your host
aren’t automatically removed. To delete all images, containers, and volumes:
```
$
 
sudo rm
 -rf /var/lib/docker
$
 
sudo rm
 -rf /var/lib/containerd
```

You have to delete any edited configuration files manually.

Next steps

Continue to Post-installation steps for Linux.
Review the topics in Develop with Docker to learn
how to build new applications using Docker.