Complete Guide to Setting Up Docker on a Linux VPS

Docker has become the industry standard for containerization, enabling developers to package applications with all dependencies and run them consistently across any environment. This guide walks you through installing Docker on a Linux VPS, configuring it for production use, and deploying your first containerized application.

Why Docker on a VPS?

Running Docker on a VPS provides several advantages: reduced resource consumption compared to virtual machines, faster deployment cycles, simplified dependency management, and seamless scaling. Whether you're running Node.js APIs, database services, or full-stack applications, Docker ensures consistency between development and production environments.

Prerequisites

• A Linux VPS (Ubuntu 20.04+ or Debian 11+ recommended)
• SSH access with sudo privileges
• At least 2GB RAM and 20GB disk space
• A package manager (apt, yum, or equivalent)

Step 1: Update System Packages

Before installing Docker, ensure your system is up to date:

sudo apt-get update
sudo apt-get upgrade -y

For RHEL-based systems (CentOS, Fedora):

sudo yum update -y

Step 2: Install Docker Engine

Using the Official Docker Repository (Ubuntu/Debian)

Add Docker's GPG key:

curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /usr/share/keyrings/docker-archive-keyring.gpg

Add Docker repository:

echo \
  "deb [arch=amd64 signed-by=/usr/share/keyrings/docker-archive-keyring.gpg] https://download.docker.com/linux/ubuntu \
  $(lsb_release -cs) stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null

Install Docker:

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

For RHEL-based Systems

sudo yum install -y yum-utils
sudo yum-config-manager --add-repo https://download.docker.com/linux/rhel/docker-ce.repo
sudo yum install docker-ce docker-ce-cli containerd.io docker-compose-plugin -y

Step 3: Start and Enable Docker Service

Start the Docker daemon:

sudo systemctl start docker

Enable Docker to start on boot:

sudo systemctl enable docker

Verify installation:

docker --version
docker run hello-world

Step 4: Configure User Permissions

Add your user to the docker group to avoid using sudo for every command:

sudo usermod -aG docker $USER

Apply group membership:

newgrp docker

Step 5: Install Docker Compose (Optional but Recommended)

For managing multi-container applications:

sudo curl -L "https://github.com/docker/compose/releases/latest/download/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose
sudo chmod +x /usr/local/bin/docker-compose
docker-compose --version

Step 6: Configure Docker Daemon

Create or edit /etc/docker/daemon.json for production settings:

{
  "log-driver": "json-file",
  "log-opts": {
    "max-size": "10m",
    "max-file": "3"
  },
  "storage-driver": "overlay2",
  "live-restore": true,
  "userland-proxy": false
}

Apply configuration:

sudo systemctl restart docker

Step 7: Deploy Your First Container

Create a simple Node.js application Dockerfile:

FROM node:18-alpine

WORKDIR /app

COPY package*.json ./
RUN npm ci --only=production

COPY . .

EXPOSE 3000

CMD ["node", "server.js"]

Build the image:

docker build -t my-node-app:latest .

Run the container:

docker run -d -p 3000:3000 --name my-app my-node-app:latest

Step 8: Docker Compose Multi-Container Setup

Create a docker-compose.yml for a Node.js + PostgreSQL stack:

version: '3.8'

services:
  app:
    build: .
    ports:
      - "3000:3000"
    environment:
      - DATABASE_URL=postgresql://user:password@db:5432/appdb
    depends_on:
      - db
    restart: unless-stopped

  db:
    image: postgres:15-alpine
    environment:
      - POSTGRES_USER=user
      - POSTGRES_PASSWORD=password
      - POSTGRES_DB=appdb
    volumes:
      - postgres_data:/var/lib/postgresql/data
    restart: unless-stopped

volumes:
  postgres_data:

Deploy:

docker-compose up -d

Step 9: Container Management

View running containers:

docker ps

View all containers:

docker ps -a

View container logs:

docker logs -f container_name

Stop a container:

docker stop container_name

Remove a container:

docker rm container_name

Step 10: Production Security Best Practices

• Keep Docker updated: Regularly run sudo apt-get update && sudo apt-get upgrade
• Use specific image tags: Avoid latest tag in production; use versioned tags
• Implement resource limits: Use --memory and --cpus flags
• Run containers as non-root: Create dedicated user in Dockerfile
• Use secrets management: Implement Docker Secrets or environment-based solutions
• Enable restart policies: Use --restart=unless-stopped for critical services
• Monitor container health: Implement health checks in docker-compose

Example health check:

HEALTHCHECK --interval=30s --timeout=3s --start-period=40s --retries=3 \
  CMD node healthcheck.js

Useful Resources

• Docker Official Documentation
• Docker Hub - Container Registry
• Docker Compose Documentation
• Best Practices for Docker

Conclusion

You now have a fully functional Docker environment on your VPS. Start small with single-container applications, then progress to multi-container setups using Docker Compose. Monitor your containers regularly, keep images small with minimal base images like Alpine, and always implement proper logging and health checks for production reliability.