How to Install Docker and Docker Compose on Ubuntu 26.04

Quick take: Docker Compose is the standard tool for defining and running multi-container applications.

Docker Compose is the standard tool for defining and running multi-container applications. Instead of managing each container individually with long docker run commands, you describe your entire application stack in a single docker-compose.yml file and bring everything up with one command: docker compose up.

This guide covers three installation methods for Docker Compose on Ubuntu 26.04 LTS (codename Resolute), released April 2026. By the end you will have Docker Engine 29.4.0 and Docker Compose v5.1.2 running, Docker configured without sudo, and a working multi-container example to confirm the setup.

Prerequisites

Before starting, ensure you have:

• A running Ubuntu 26.04 LTS system (server or desktop)
• A user account with sudo privileges
• Internet connectivity to reach Docker's package repositories and GitHub
• At least 2 GB of free disk space

If this is a fresh server, update the system first:

sudo apt update && sudo apt upgrade -y

Method 1: Install from Docker's Official Repository (Recommended)

This method gives you the latest Docker Engine and Compose versions directly from Docker Inc., with the fastest security update cadence. Docker Compose v2 is bundled as a plugin (docker-compose-plugin) and invoked as docker compose (without a hyphen).

Step 1 — Remove Old Docker Packages

Remove any conflicting Docker packages that may have been installed from the Ubuntu repository:

for pkg in docker.io docker-doc docker-compose docker-compose-v2 \
           podman-docker containerd runc; do
    sudo apt remove -y $pkg 2>/dev/null
done

Step 2 — Install Dependencies and Add Docker GPG Key

# Install required packages
sudo apt update
sudo apt install -y ca-certificates curl

# Create the keyrings directory
sudo install -m 0755 -d /etc/apt/keyrings

# Download Docker's official GPG key
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

Step 3 — Add the Docker Repository

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

sudo apt update

Step 4 — Install Docker Engine and Docker Compose Plugin

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

This single command installs:

• docker-ce — Docker Engine (Community Edition)
• docker-ce-cli — the docker command-line interface
• containerd.io — the container runtime
• docker-buildx-plugin — extended build capabilities (multi-platform builds)
• docker-compose-plugin — Docker Compose v2, used as docker compose

Method 2: Install from Ubuntu Repository (Simpler, Slightly Older Version)

If you prefer to use Ubuntu's own tested packages and do not need the very latest version, the Ubuntu repository provides a stable build with integrated security updates:

sudo apt update
sudo apt install -y docker-compose-v2

This automatically installs docker.io (Docker Engine from the Ubuntu repository) as a dependency. The docker-compose-v2 package provides the docker compose command. This is the simplest one-command install, though the Docker version may lag behind the official Docker repository by a few minor releases.

Method 3: Manual Binary Installation (Specific Version Control)

For air-gapped environments, specific version pinning, or per-user installation without system-wide changes, download the Docker Compose binary directly from GitHub:

# Set Docker config directory
DOCKER_CONFIG=${DOCKER_CONFIG:-$HOME/.docker}
mkdir -p $DOCKER_CONFIG/cli-plugins

# Download Docker Compose v5.1.2 binary
curl -SL https://github.com/docker/compose/releases/download/v5.1.2/docker-compose-linux-x86_64 \
     -o $DOCKER_CONFIG/cli-plugins/docker-compose

# Make it executable
chmod +x $DOCKER_CONFIG/cli-plugins/docker-compose

For ARM64 systems (Raspberry Pi, AWS Graviton, Apple Silicon VMs):

curl -SL https://github.com/docker/compose/releases/download/v5.1.2/docker-compose-linux-aarch64 \
     -o $DOCKER_CONFIG/cli-plugins/docker-compose
chmod +x $DOCKER_CONFIG/cli-plugins/docker-compose

Note: Manual installs do not auto-update. You must repeat this process to upgrade to a newer version. For most users, Method 1 (Docker official repository) is preferred.

Verify the Installation

After completing any of the three methods above, verify both Docker Engine and Docker Compose are working correctly:

# Check Docker Engine version
docker --version

# Check Docker Compose version
docker compose version

# Run the hello-world container to verify Docker is functional
sudo docker run hello-world

Expected output:

Docker version 29.4.0, build abcdef1
Docker Compose version v5.1.2

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

Run Docker Without sudo (Recommended)

By default, the Docker daemon runs as root and requires sudo for every command. Adding your user to the docker group allows running Docker commands without sudo:

# Add your user to the docker group
sudo usermod -aG docker $USER

# Apply the new group membership without logging out
newgrp docker

# Verify it works without sudo
docker run hello-world

Enable Docker to Start on Boot

Docker Engine is enabled on boot by default when installed from the Docker official repository. Verify and enable it manually if needed:

# Enable Docker and containerd to start on boot
sudo systemctl enable docker.service
sudo systemctl enable containerd.service

# Check current status
sudo systemctl status docker

Your First docker-compose.yml File

Create a working directory and a docker-compose.yml file to test your installation with a real multi-container application. This example runs WordPress with MariaDB and Redis — three containers defined in one file:

mkdir -p ~/docker-test && cd ~/docker-test
nano docker-compose.yml

Paste the following content:

services:

  db:
    image: mariadb:11
    restart: always
    environment:
      MARIADB_ROOT_PASSWORD: rootpass
      MARIADB_DATABASE: wordpress
      MARIADB_USER: wpuser
      MARIADB_PASSWORD: wppass
    volumes:
      - db_data:/var/lib/mysql
    healthcheck:
      test: ["CMD", "mariadb-admin", "ping", "-h", "localhost"]
      interval: 10s
      timeout: 5s
      retries: 5

  redis:
    image: redis:7-alpine
    restart: always
    healthcheck:
      test: ["CMD", "redis-cli", "ping"]
      interval: 10s
      retries: 3

  wordpress:
    image: wordpress:6-apache
    restart: always
    depends_on:
      db:
        condition: service_healthy
      redis:
        condition: service_healthy
    ports:
      - "8080:80"
    environment:
      WORDPRESS_DB_HOST: db
      WORDPRESS_DB_USER: wpuser
      WORDPRESS_DB_PASSWORD: wppass
      WORDPRESS_DB_NAME: wordpress
    volumes:
      - wp_data:/var/www/html

volumes:
  db_data:
  wp_data:

Start the stack:

# Start all containers in the background (-d = detached mode)
docker compose up -d

# Watch the logs to see all three containers start
docker compose logs -f

Once all containers are healthy, open http://localhost:8080 in your browser to see the WordPress setup page. To stop the stack:

docker compose down

Essential Docker Compose Commands

Using Environment Variables with .env Files

Store sensitive values like database passwords outside your docker-compose.yml in a .env file in the same directory:

# .env file
MARIADB_ROOT_PASSWORD=your-strong-root-password
MARIADB_DATABASE=appdb
MARIADB_USER=appuser
MARIADB_PASSWORD=your-strong-app-password
APP_PORT=8080

Reference these variables in docker-compose.yml:

services:
  db:
    image: mariadb:11
    environment:
      MARIADB_ROOT_PASSWORD: ${MARIADB_ROOT_PASSWORD}
      MARIADB_DATABASE: ${MARIADB_DATABASE}
      MARIADB_USER: ${MARIADB_USER}
      MARIADB_PASSWORD: ${MARIADB_PASSWORD}
    ports:
      - "${APP_PORT}:80"

Add .env to .gitignore to prevent committing secrets to version control:

echo ".env" >> .gitignore

Troubleshooting on Ubuntu 26.04

Issue 1: "Cannot connect to the Docker daemon" Error

If you see Cannot connect to the Docker daemon at unix:///var/run/docker.sock, the Docker service is not running. Start it:

sudo systemctl start docker
sudo systemctl status docker

Issue 2: Permission Denied Without sudo

If you added yourself to the docker group but still see permission errors, either the group membership has not taken effect yet or newgrp docker was not run. Log out and log back in, or run:

newgrp docker
# Verify group membership
groups $USER

Issue 3: Old Images Not Compatible with cgroup v2

Ubuntu 26.04 uses cgroup v2 exclusively (no cgroup v1 fallback). Very old container images — Alpine 3.13 and earlier, legacy CentOS 7 images, and some older MySQL images — may fail to start. Update to current image versions. For MySQL, use mysql:8.4 or mariadb:11 which have full cgroup v2 support.

Issue 4: docker-compose Command Not Found

Docker Compose v2 uses docker compose (space, not hyphen). The old docker-compose (with hyphen) command was deprecated in v2. If scripts rely on the hyphenated form, create an alias:

# Add to ~/.bashrc for persistent alias
echo 'alias docker-compose="docker compose"' >> ~/.bashrc
source ~/.bashrc

Issue 5: Port Already in Use

If docker compose up fails with "port is already allocated" or "address already in use," another service is using that port. Find it:

# Find what is using port 8080
sudo ss -tlnp | grep 8080
# Or use lsof
sudo lsof -i :8080

Either stop the conflicting service or change the host port in your docker-compose.yml (e.g. change "8080:80" to "8081:80").

Issue 6: Verify Docker Repository Is Correctly Configured

If apt update throws errors about the Docker repository, verify the repository configuration and GPG key are correct:

# Check the repository file
cat /etc/apt/sources.list.d/docker.list

# Should output something like:
# deb [arch=amd64 signed-by=/etc/apt/keyrings/docker.asc] 
# https://download.docker.com/linux/ubuntu resolute stable

# Verify the GPG key exists
ls -la /etc/apt/keyrings/docker.asc

Upgrading Docker Compose

If you installed via Method 1 (Docker official repository), upgrade Docker Compose along with all Docker packages through the normal APT update process:

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

For Method 3 (manual binary), download the new binary and replace the existing one:

# Check latest version at:
# https://github.com/docker/compose/releases

NEW_VERSION="v5.1.2"  # Replace with latest version
curl -SL "https://github.com/docker/compose/releases/download/${NEW_VERSION}/docker-compose-linux-x86_64" \
     -o $HOME/.docker/cli-plugins/docker-compose
chmod +x $HOME/.docker/cli-plugins/docker-compose
docker compose version

Final Thoughts

How to Install Docker and Docker Compose on Ubuntu 26.04 is worth reviewing with a practical lens: understand the risk or opportunity, map it to your environment, and take clear next steps instead of reacting to headlines.