🐳 Install Docker on a Linux VPS

This guide explains how to install Docker and Docker Compose on your Linux VPS. Docker is a containerization platform that allows you to create, deploy and run applications in isolated containers, making application deployment and management easier.

📋 Prerequisites

• A Linux VPS with root or sudo access
• Ubuntu 20.04+ or Debian 11+ (or CentOS 7+/RHEL 7+)
• At least 1 GB of RAM (2 GB recommended)
• A stable Internet connection

💡 Infrastructure Recommendation

Docker requires fast disks for compilation and intensive I/O operations. We recommend our NVMe VPS for optimal performance when using Docker. NVMe drives offer speeds up to 10x faster than traditional SSDs, significantly accelerating Docker image builds and container startup times.

⚠️ Important before installation

• Check your system : Docker requires a 64-bit system
• Backup your data : Installation may modify some system configurations
• Installation time : Installation typically takes 5 to 10 minutes

🔧 Installation on Ubuntu/Debian

Step 1: Update the system

# Update package list
sudo apt update

# Update installed packages
sudo apt upgrade -y

Step 2: Install dependencies

# Install necessary packages
sudo apt install -y \
    ca-certificates \
    curl \
    gnupg \
    lsb-release

Step 3: Add Docker's official GPG key

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

# Download and add GPG key
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /etc/apt/keyrings/docker.gpg

# Set correct permissions
sudo chmod a+r /etc/apt/keyrings/docker.gpg

Step 4: Configure Docker repository

# Add Docker repository
echo \
  "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.gpg] https://download.docker.com/linux/ubuntu \
  $(lsb_release -cs) stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null

Step 5: Install Docker Engine

# Update package list
sudo apt update

# Install Docker Engine, containerd and Docker Compose
sudo apt install -y docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin

Step 6: Verify installation

# Verify Docker is installed correctly
sudo docker --version

# Verify Docker Compose is installed
sudo docker compose version

🔧 Installation on CentOS/RHEL

Step 1: Update the system

# Update packages
sudo yum update -y

Step 2: Install dependencies

# Install necessary packages
sudo yum install -y yum-utils

Step 3: Add Docker repository

# Add Docker repository
sudo yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo

Step 4: Install Docker Engine

# Install Docker Engine, containerd and Docker Compose
sudo yum install -y docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin

Step 5: Start Docker

# Start Docker service
sudo systemctl start docker

# Enable Docker on boot
sudo systemctl enable docker

Step 6: Verify installation

# Verify Docker is installed correctly
sudo docker --version

# Verify Docker Compose is installed
sudo docker compose version

👤 Step 7: Configure permissions (Important)

By default, Docker requires root privileges. To run Docker without sudo, add your user to the docker group:

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

# Apply changes (logout/login required)
newgrp docker

Verify permissions

# Test Docker without sudo
docker run hello-world

If this command works without error, Docker is correctly configured!

🧪 Step 8: Test Docker

Run a test container

# Run Hello World container
docker run hello-world

This command will:

1. Download the hello-world image from Docker Hub
2. Create a container from this image
3. Run the container
4. Display a confirmation message

Check containers

# List running containers
docker ps

# List all containers (including stopped)
docker ps -a

# List Docker images
docker images

🐙 Step 9: Install Docker Compose (if not included)

If Docker Compose was not installed with Docker Engine, install it separately:

On Ubuntu/Debian

# Download Docker Compose
sudo curl -L "https://github.com/docker/compose/releases/latest/download/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose

# Make executable
sudo chmod +x /usr/local/bin/docker-compose

# Verify installation
docker-compose --version

On CentOS/RHEL

# Download Docker Compose
sudo curl -L "https://github.com/docker/compose/releases/latest/download/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose

# Make executable
sudo chmod +x /usr/local/bin/docker-compose

# Verify installation
docker-compose --version

📦 Essential Docker commands

Image management

# Download an image
docker pull image-name:tag

# List images
docker images

# Remove an image
docker rmi image-name

# Clean unused images
docker image prune -a

Container management

# Create and start a container
docker run image-name

# Create a container in background (detached)
docker run -d image-name

# List running containers
docker ps

# Stop a container
docker stop container-id

# Start a stopped container
docker start container-id

# Restart a container
docker restart container-id

# Remove a container
docker rm container-id

# View container logs
docker logs container-id

# Execute a command in a running container
docker exec -it container-id /bin/bash

Docker Compose

# Start services defined in docker-compose.yml
docker compose up

# Start in background
docker compose up -d

# Stop services
docker compose down

# View logs
docker compose logs

# Rebuild images
docker compose build

🔒 Securing Docker

Configure Docker daemon (optional)

Create or modify /etc/docker/daemon.json:

sudo nano /etc/docker/daemon.json

Add the following configuration:

{
  "log-driver": "json-file",
  "log-opts": {
    "max-size": "10m",
    "max-file": "3"
  }
}

Restart Docker:

sudo systemctl restart docker

Limit Docker access

By default, users in the docker group have root-equivalent privileges. For more security, you can:

1. Only give access to trusted users
2. Use Docker rootless (advanced installation)
3. Configure security policies via AppArmor or SELinux

🔄 Update Docker

On Ubuntu/Debian

# Update packages
sudo apt update

# Update Docker
sudo apt upgrade docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin

On CentOS/RHEL

# Update Docker
sudo yum update docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin

🗑️ Uninstall Docker

If you want to uninstall Docker:

On Ubuntu/Debian

# Stop Docker
sudo systemctl stop docker

# Uninstall packages
sudo apt purge docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin docker-ce-rootless-extras

# Remove images, containers and volumes
sudo rm -rf /var/lib/docker
sudo rm -rf /var/lib/containerd

On CentOS/RHEL

# Stop Docker
sudo systemctl stop docker

# Uninstall packages
sudo yum remove docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin docker-ce-rootless-extras

# Remove images, containers and volumes
sudo rm -rf /var/lib/docker
sudo rm -rf /var/lib/containerd

❓ Common Issues

Error "Cannot connect to the Docker daemon"

Solution:

# Check Docker service is started
sudo systemctl status docker

# Start Docker if necessary
sudo systemctl start docker

# Check you are in docker group
groups

Error "Permission denied"

Solution:

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

# Log out and log back in

Docker is slow

Possible solutions:

• Check disk space: df -h
• Clean unused images: docker system prune -a
• Check available RAM: free -h

📝 Example: Deploy a simple application

Create a docker-compose.yml file

# Create a directory for your project
mkdir my-project
cd my-project

# Create docker-compose.yml file
nano docker-compose.yml

Example content:

version: '3.8'

services:
  web:
    image: nginx:latest
    ports:
      - "80:80"
    volumes:
      - ./html:/usr/share/nginx/html
    restart: unless-stopped

Start the application

# Start services
docker compose up -d

# Verify container is running
docker ps

📞 Need Help?

If you encounter difficulties installing Docker, please contact Infrawire support. Our team is available to help you.

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Note : Docker is a powerful tool that greatly simplifies application deployment. Take time to understand the basic concepts before deploying applications in production.