Install Docker Engine on Ubuntu

george

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

Prerequisites

Firewall limitations

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

If you use ufw or firewalld to manage firewall settings, be aware that when you expose container ports using Docker, these ports bypass your firewall rules. For more information, refer to Docker and ufw.
Docker is only compatible with iptables-nft and iptables-legacy. Firewall rules created with nft are not supported on a system with Docker installed. Make sure that any firewall rulesets you use are created with iptables or ip6tables, and that you add them to the DOCKER-USER chain, see Packet filtering and firewalls.

OS requirements

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

Ubuntu Oracular 24.10
Ubuntu Noble 24.04 (LTS)
Ubuntu Jammy 22.04 (LTS)
Docker Engine for Ubuntu is compatible with x86_64 (or amd64), armhf, arm64, s390x, and ppc64le (ppc64el) architectures.

Installation on Ubuntu derivative distributions, such as Linux Mint, is not officially supported (though it may work).

Uninstall old versions

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

Your Linux distribution may provide unofficial Docker packages, which may conflict with the official packages provided by Docker. You must uninstall these packages before you install the official version of Docker Engine.
The unofficial packages to uninstall are:

docker.io
docker-compose
docker-compose-v2
docker-doc
podman-docker

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:

for pkg in docker.io docker-doc docker-compose docker-compose-v2 podman-docker containerd runc; do sudo apt-get remove $pkg; done

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 script. 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 apt repository. Afterward, you can install and update Docker from the repository.

1.Set up Docker's apt repository.

# Add Docker's official GPG key:
sudo apt-get update
sudo apt-get install ca-certificates curl
sudo install -m 0755 -d /etc/apt/keyrings
sudo curl -fsSL https://download.docker.com/linux/ubuntu/gpg -o /etc/apt/keyrings/docker.asc
sudo chmod a+r /etc/apt/keyrings/docker.asc

# Add the repository to Apt sources:
echo \
  "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.asc] https://download.docker.com/linux/ubuntu \
  $(. /etc/os-release && echo "${UBUNTU_CODENAME:-$VERSION_CODENAME}") stable" | \
  sudo tee /etc/apt/sources.list.d/docker.list > /dev/null
sudo apt-get update

2.Install the Docker packages.

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

3.Verify that the 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 postinstall to 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 the installation instructions, choosing the new version you want to install.

george

@george
在国内使用 Docker 拉取镜像时，经常会遇到镜像源无法访问的问题，为了解决这一问题，下面将介绍如何配置 DaoCloud 镜像源，确保在国内快速稳定的下载镜像。

通过上述步骤新安装的 Docker 一般不存在文件/etc/docker/daemon.json，没关系，我们直接使用vim /etc/docker/daemon.json进行创建并编辑，输入以下内容：

{
    "registry-mirrors": [
        "https://docker.m.daocloud.io"
    ]
}

保存文件后重启 Docker 服务，新的镜像源即可生效：

systemctl daemon-reload
systemctl restart docker