Demo Setup and Install Docker

In this lesson you’ll install Docker Engine on an Ubuntu VM and verify the installation by running the official hello-world container. This guide follows the official Docker Engine installation flow for Ubuntu. Keep a browser open to the Docker documentation for reference: https://docs.docker.com/engine/install/ubuntu/

Prerequisites

Requirement	Details
Supported OS	64-bit Ubuntu release (e.g., 22.04, 24.04)
Architecture	`amd64` or `arm64` (check with `dpkg --print-architecture`)
Privileges	Sudo privileges on the VM
iptables mode	Some Docker setups expect `iptables-nft`. If you have custom firewall rules, verify compatibility first.

1 — Verify OS release and architecture

Confirm the distribution and version:

cat /etc/*release*

Example output from this VM:

DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=24.04
DISTRIB_CODENAME=noble
DISTRIB_DESCRIPTION="Ubuntu 24.04.4 LTS"
PRETTY_NAME="Ubuntu 24.04.4 LTS"
NAME="Ubuntu"
VERSION_ID="24.04"
VERSION="24.04.4 LTS (Noble Numbat)"
VERSION_CODENAME=noble
ID=ubuntu
ID_LIKE=debian
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
UBUNTU_CODENAME=noble
LOGO=ubuntu-logo

Confirm the system architecture is 64-bit:

dpkg --print-architecture

Example output:

arm64

2 — Uninstall old Docker packages (optional / precaution)

If older Docker packages are installed, remove them first. On production systems take care — removing packages may impact running services.

If this VM runs production services, do NOT remove packages unless you understand the consequences. Back up important data and confirm dependencies before uninstalling packages.

A conservative removal command (adjust package names if needed):

sudo apt remove -y docker docker-engine docker.io containerd runc

You can inspect installed Docker-related packages first:

dpkg -l | grep -E 'docker|containerd|runc'

3 — Add Docker’s APT repository (recommended)

Follow these steps to configure the official Docker repository, which ensures you get the latest stable Docker packages.

Update apt and install prerequisites:

sudo apt update
sudo apt install -y ca-certificates curl gnupg

Create the keyrings directory and install Docker’s 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

Add the Docker APT repository, using the system architecture and Ubuntu codename dynamically:

sudo tee /etc/apt/sources.list.d/docker.list > /dev/null <<EOF
deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.gpg] \
  https://download.docker.com/linux/ubuntu $(. /etc/os-release && echo "$UBUNTU_CODENAME") stable
EOF

Update apt and install Docker Engine, the CLI, containerd, and the Buildx / Compose plugins:

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

Packages installed typically include:

Package	Purpose
`docker-ce`	Docker Engine (Community Edition)
`docker-ce-cli`	Docker command-line client
`containerd.io`	Container runtime used by Docker
`docker-buildx-plugin`	Buildx plugin for advanced build features
`docker-compose-plugin`	Compose v2 plugin

Confirm installation prompts during apt and accept (Y) if required.

5 — Enable and start Docker

Enable Docker to start automatically at boot and start the service immediately:

sudo systemctl enable --now docker

Check Docker service status:

sudo systemctl status docker --no-pager

You should see output similar to:

● docker.service - Docker Application Container Engine
     Loaded: loaded (/lib/systemd/system/docker.service; enabled; vendor preset: enabled)
     Active: active (running) since ...
     Docs: https://docs.docker.com

6 — Verify the installation: run hello-world

Pull and run the hello-world image to confirm Docker can download images and run containers:

sudo docker run hello-world

Expected (abbreviated) output:

Unable to find image 'hello-world:latest' locally
latest: Pulling from library/hello-world
...
Status: Downloaded newer image for hello-world:latest

Hello from Docker!
This message shows that your installation appears to be working correctly.

To generate this message, Docker took the following steps:
 1. The Docker client contacted the Docker daemon.
 2. The Docker daemon pulled the "hello-world" image from the Docker Hub.
 3. The Docker daemon created a new container from that image which runs the
    executable that produces the output you are currently reading.
 4. The Docker daemon streamed that output to the Docker client, which sent it to your terminal.

Post-installation tips

To run Docker commands without sudo, create the docker group and add your user:

sudo groupadd docker        # may fail if group already exists — that's fine
sudo usermod -aG docker $USER
# Log out and log back in (or run `newgrp docker`) for group change to take effect

If you add your user to the docker group, understand the security implications: members of the docker group effectively have root-equivalent access to the host. See Docker’s post-installation docs for details.

For Compose and Buildx usage, refer to the Docker docs for examples and plugin configuration.
If you have specialized firewall rules (iptables/nftables), verify Docker’s networking behavior and adjust rules to avoid conflicts.

Links and references

Docker Engine on Ubuntu — official install guide: https://docs.docker.com/engine/install/ubuntu/
Docker post-installation steps (manage Docker as a non-root user): https://docs.docker.com/engine/install/linux-postinstall/
Docker documentation home: https://docs.docker.com/

This completes the Docker Engine installation and verification on Ubuntu.

Introduction

Docker Commands

Docker Images

Docker Compose

Docker Engine, Storage

Docker Networking

Docker Registry

Docker on Mac & Windows

Container Orchestration - Docker Swarm & Kubernetes

Conclusion

Docker Run Commands

Demo Setup and Install Docker

Prerequisites

1 — Verify OS release and architecture

2 — Uninstall old Docker packages (optional / precaution)

3 — Add Docker’s APT repository (recommended)

5 — Enable and start Docker

6 — Verify the installation: run hello-world

Post-installation tips

Links and references

Watch Video

​Prerequisites

​1 — Verify OS release and architecture

​2 — Uninstall old Docker packages (optional / precaution)

​3 — Add Docker’s APT repository (recommended)

​4 — Install Docker Engine and related packages

​5 — Enable and start Docker

​6 — Verify the installation: run hello-world

​Post-installation tips

​Links and references

Watch Video

Prerequisites

1 — Verify OS release and architecture

2 — Uninstall old Docker packages (optional / precaution)

3 — Add Docker’s APT repository (recommended)

4 — Install Docker Engine and related packages

5 — Enable and start Docker

6 — Verify the installation: run hello-world

Post-installation tips

Links and references