Dokku — The Smallest PaaS Implementation You've Ever Seen

What Dokku Does

• Git Push Deploy: Push code, Dokku builds and deploys automatically
• Buildpacks: Auto-detect language and build (Node.js, Python, Ruby, Go, PHP, Java, etc.)
• Dockerfile: Deploy any Dockerfile-based application
• Docker Image: Deploy pre-built Docker images directly
• Automatic HTTPS: Let's Encrypt certificates provisioned and renewed automatically
• Zero Downtime: Zero-downtime deploys with health checks
• Scaling: Scale app processes horizontally
• Plugins: PostgreSQL, MySQL, Redis, MongoDB, RabbitMQ, and 100+ community plugins
• Domains: Custom domain management with automatic routing
• Environment Variables: Secure config management

Architecture

Developer
    │
    │ git push dokku main
    │
┌───┴───────────────────────────────────┐
│  Dokku Server                         │
│  ┌─────────┐  ┌────────────────────┐  │
│  │ Git     │──│ Builder            │  │
│  │ Receive │  │ (Buildpack/Docker) │  │
│  └─────────┘  └────────┬───────────┘  │
│                         │              │
│  ┌──────────────────────┴───────────┐ │
│  │  Docker Container (your app)     │ │
│  └──────────────────────────────────┘ │
│  ┌──────────────────────────────────┐ │
│  │  Nginx (reverse proxy + SSL)    │ │
│  └──────────────────────────────────┘ │
└───────────────────────────────────────┘

Getting Started

1. Install Dokku

# On a fresh Ubuntu 22.04+ server
wget -NP . https://dokku.com/install/v0.34.8/bootstrap.sh
sudo DOKKU_TAG=v0.34.8 bash bootstrap.sh

# Set domain
dokku domains:set-global your-server.com

# Add your SSH key
echo "your-public-key" | dokku ssh-keys:add admin

2. Create App

dokku apps:create my-node-app

3. Add Database

# Install PostgreSQL plugin
dokku plugin:install https://github.com/dokku/dokku-postgres.git

# Create database and link to app
dokku postgres:create my-db
dokku postgres:link my-db my-node-app
# DATABASE_URL is automatically set in app environment

4. Deploy

# On your local machine
git remote add dokku dokku@your-server.com:my-node-app
git push dokku main

5. Enable HTTPS

dokku letsencrypt:enable my-node-app
# Auto-renews via cron

Common Commands

# App management
dokku apps:list                          # List all apps
dokku apps:create my-app                 # Create app
dokku apps:destroy my-app                # Delete app

# Configuration
dokku config:set my-app KEY=value        # Set env var
dokku config:show my-app                 # Show all env vars

# Domains & SSL
dokku domains:add my-app example.com     # Add custom domain
dokku letsencrypt:enable my-app          # Enable HTTPS

# Scaling
dokku ps:scale my-app web=3 worker=2     # Scale processes

# Databases (plugins)
dokku postgres:create db1                # Create PostgreSQL
dokku redis:create cache1                # Create Redis
dokku postgres:link db1 my-app           # Link to app

# Logs & debugging
dokku logs my-app -t                     # Tail logs
dokku enter my-app web                   # Shell into container
dokku run my-app npm run migrate         # Run one-off command

Supported Languages

Dokku vs Alternatives

FAQ

Q: Should I pick Dokku or CapRover? A: Dokku is closer to the Heroku experience, CLI-first with a mature buildpack ecosystem. CapRover has a nice web UI and suits users who prefer avoiding the command line. Feature-wise they're comparable — it's personal preference.

Q: How many apps can one server run? A: It depends on per-app resource usage. A 4 GB RAM VPS typically runs 5–10 small Node.js/Python web apps plus their databases. Set memory limits on each app.

Q: Does it support multi-server clusters? A: Dokku defaults to a single-server architecture. The dokku-scheduler-k3s plugin extends it to a K3s cluster. For multi-server needs, Coolify or CapRover are also worth considering.

Sources & Credits

• GitHub: dokku/dokku — 31.9K+ ⭐ | MIT
• Website: dokku.com