How to install Docker on a VPS, step by step

Almost every guide on this site starts the same way: "you need Docker on your server". This is that part, explained once and properly, so it doesn't have to be repeated in every tutorial.

Docker packages an application together with everything it needs to run. In practice that means installing Listmonk, Immich or Activepieces stops being an afternoon of broken dependencies and turns into two or three commands that behave the same on any server.

What you will need

A VPS with a clean Ubuntu install and root access. Almost any provider works; we recorded the process on a Hostinger VPS because their panel ships ready-made templates, but the commands are identical on DigitalOcean, Hetzner or Contabo.

1. Connect to the server over SSH

Open a terminal and log in with the IP your provider gave you:

ssh root@YOUR_SERVER_IP

The first time, it will ask whether you trust the machine. Type yes. If you are using a password, you will not see anything as you type it: that is normal, the terminal does not show asterisks.

2. Update the system before installing anything

apt update && apt upgrade -y

This step gets skipped often and it is the one that prevents half the strange problems. A system with old packages can install a version of Docker that does not match the documentation you are following.

3. Install Docker with the official script

Docker maintains a script that detects the distribution and sets up the correct repository:

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

It takes a minute or two. When it finishes, Docker is already running as a system service.

4. Give your user permissions

By default only root can talk to Docker. Working as root all the time is a bad idea, so add your user to the docker group:

usermod -aG docker $USER

And now the part that confuses everyone: that change does not apply until you log out and log back in. Type exit, connect again over SSH and continue.

5. Check that it worked

docker run hello-world

If you see a message starting with "Hello from Docker!", you are done. That command downloaded a minimal image, ran it and shut it down: you just completed the whole cycle.

It is also worth checking the version and that the service starts on its own:

docker --version
systemctl is-enabled docker

The second one should answer enabled. If it says disabled, turn it on with systemctl enable docker or your containers will not come back after a reboot.

Common mistakes

Installing docker.io from the Ubuntu repositories. It works, but it tends to lag several versions behind and does not include the modern Compose plugin. Tutorials that use docker compose (no hyphen) will fail.

Mixing up docker-compose and docker compose. The first is the old Python tool that had to be installed separately. The second is the current plugin and it comes with the official script. If a tutorial uses the hyphen, it is probably from before 2023.

Leaving the application's port open to the internet. Many containers publish their port on every interface. Before exposing anything, put a reverse proxy with HTTPS in front, or at least restrict access with the firewall.

Alternatives

If the command line is not your thing, there are two paths to the same place:

• Coolify gives you a panel on top of Docker to deploy applications with clicks. It is still your server and your data, just with an interface.
• ServerAvatar and similar panels manage the whole server, not only the containers. They cost a subscription but remove a fair amount of friction.

Neither saves you from understanding what a container is. They only save you from typing it.