Ubuntu (original) (raw)

To get started with Docker Engine on Ubuntu, make sure youmeet the prerequisites, and then follow theinstallation steps.

Firewall limitations

Warning

Before you install Docker, make sure you consider the following security implications and firewall incompatibilities.

OS requirements

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

Docker Engine for Ubuntu is compatible with x86_64 (or amd64), armhf, arm64, s390x, and ppc64le (ppc64el) architectures.

Uninstall old versions

Before you can install Docker Engine, you need to uninstall any conflicting packages.

Distro maintainers provide unofficial distributions of Docker packages in APT. You must uninstall these packages before you can install the official version of Docker Engine.

The unofficial packages to uninstall are:

Moreover, Docker Engine depends on containerd and runc. Docker Engine bundles these dependencies as one bundle: containerd.io. If you have installed the containerd or runc previously, uninstall them to avoid conflicts with the versions bundled with Docker Engine.

Run the following command to uninstall all conflicting packages:

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 theuninstall Docker Engine section.

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

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.

  1. Set up Docker's apt repository.

    Note

    If you use an Ubuntu derivative distro, such as Linux Mint, you may need to use UBUNTU_CODENAME instead of VERSION_CODENAME.

  2. Install the Docker packages.

To install the latest version, run:
To install a specific version of Docker Engine, start by listing the available versions in the repository:
Select the desired version and install:

  1. Verify that the Docker Engine installation is successful by running thehello-world image.
    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.

Tip

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 toLinux postinstallto allow non-privileged users to run Docker commands and for other optional configuration steps.

Upgrade Docker Engine

To upgrade Docker Engine, follow step 2 of theinstallation 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.

  1. Go tohttps://download.docker.com/linux/ubuntu/dists/.
  2. Select your Ubuntu version in the list.
  3. Go to pool/stable/ and select the applicable architecture (amd64,armhf, arm64, or s390x).
  4. 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
  5. Install the .deb packages. Update the paths in the following example to where you downloaded the Docker packages.
    The Docker daemon starts automatically.
  6. Verify that the Docker Engine installation is successful by running thehello-world image.
    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.

Tip

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 toLinux postinstallto 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 theinstallation procedure, pointing to the new files.

Install using the convenience script

Docker provides a convenience script athttps://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 theinstall 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 thedocker-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:

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:

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

You have now successfully installed and started Docker Engine. The dockerservice 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 thepost-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 torun the Docker daemon as a non-root user (rootless mode).

Install pre-releases

Docker also provides a convenience script athttps://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:

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.

  1. Uninstall the Docker Engine, CLI, containerd, and Docker Compose packages:
  2. Images, containers, volumes, or custom configuration files on your host aren't automatically removed. To delete all images, containers, and volumes:

You have to delete any edited configuration files manually.