How to install Docker Engine on Ubuntu Server

1. Check your Ubuntu installation

Complete the Ubuntu Server guide first, or confirm you have a supported release, internet access, and an account with sudo permissions.

cat /etc/os-release
dpkg --print-architecture

Use the actual output to choose the right installation instructions. This walkthrough follows the official Ubuntu APT-repository method. It is separate from Docker Desktop and does not use Ubuntu’s docker.io package.

On an existing installation, conflicting container packages can require migration or removal. Do not blindly uninstall them from a working server. Check Docker’s current prerequisites and make a migration plan first.

2. Add Docker’s repository and signing key

Install the tools needed to fetch the repository key, create the key directory, and make the key readable to APT:

sudo apt update
sudo apt 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

Create the repository definition. The expressions below read your Ubuntu codename and package architecture rather than assuming a particular release. Paste the whole block, including the final EOF line, into a Bash shell:

sudo tee /etc/apt/sources.list.d/docker.sources > /dev/null <<EOF
Types: deb
URIs: https://download.docker.com/linux/ubuntu
Suites: $(. /etc/os-release && echo "${UBUNTU_CODENAME:-$VERSION_CODENAME}")
Components: stable
Architectures: $(dpkg --print-architecture)
Signed-By: /etc/apt/keyrings/docker.asc
EOF

This is the repository-based installation path documented by Docker. It keeps later engine updates in the normal APT workflow.

3. Install the engine and plugins

Refresh APT after adding the repository, then install the engine, container runtime, build plugin, and Compose plugin:

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

Check the service and command versions:

sudo systemctl status docker --no-pager
sudo docker version
sudo docker compose version

If the service is not active on this fresh install, start it with sudo systemctl enable --now docker and inspect any errors. Compose is invoked as docker compose with a space.

These examples keep sudo in Docker commands. Membership in the Docker group grants powerful access to the host; understand that tradeoff before allowing an account to control the engine without sudo.

4. Run a small test container

The official test image checks whether Docker can pull an image and run a container:

sudo docker run --rm hello-world

A successful run prints a greeting and an explanation of what the engine did. The --rm option removes the test container after it exits; the downloaded image can remain in the local cache.

Now check that no unexpected containers are running:

sudo docker ps

This test does not publish a service port. If the pull fails, investigate DNS, internet access, repository connectivity, and the actual error message before changing container settings.

5. Understand ports before hosting a service

A running container is not automatically a reachable website. A published port connects a host address and port to a container port. Without a specified host address, Docker normally publishes to all host interfaces.

Binding a port to a particular LAN address narrows where it is published, but routing and firewall configuration still control who can reach it. Binding to 127.0.0.1 on a current Docker release makes it accessible through the host’s loopback interface. See Docker’s port-publishing guide for the details and older-version caveats.

6. Troubleshoot before adding an application

Once the engine and Compose checks work, you have the foundation for the Jellyfin guide. Keep application configuration and backups organized from the start.