RailsFast Demo

Deployment Guide

From localhost to production in one command

Server rack with glowing lights
Your code, running everywhere

Deploying a RailsFast app is designed to be painless. Kamal 2 handles everything: building Docker images, pushing to your registry, and rolling out zero-downtime deploys.

Prerequisites

Before deploying, you'll need:

  • A server (any VPS works: Hetzner, DigitalOcean, AWS, etc.)
  • A domain name pointed to your server
  • Docker installed locally
  • Your config/deploy.yml configured

One-Command Deploy

# First time? Set up the server
kamal setup

# Every deploy after that
kamal deploy

That's it. Kamal builds your Docker image, pushes it to your container registry, and deploys it with zero downtime.

What Happens Under the Hood

When you run kamal deploy, here's what happens:

  1. Build — Docker builds your app image using the included Dockerfile
  2. Push — The image is pushed to your container registry (ECR, Docker Hub, etc.)
  3. Pull — Your server pulls the new image
  4. Boot — The new container starts and health checks pass
  5. Switch — Traffic is routed to the new container
  6. Cleanup — The old container is stopped and removed

Database Setup

RailsFast includes a PostgreSQL accessory in deploy.yml:

accessories:
  postgres:
    image: postgres:15
    host: your-server-ip
    env:
      secret:
        - POSTGRES_USER
        - POSTGRES_PASSWORD
    directories:
      - data:/var/lib/postgresql/data

Automatic nightly backups are also configured out of the box.

SSL Certificates

Kamal's built-in Thruster proxy handles SSL automatically via Let's Encrypt. Just set your domain in deploy.yml:

proxy:
  ssl: true
  host: yourdomain.com

Environment Variables

Secrets are managed in .kamal/secrets and injected at deploy time. Never commit secrets to git — Kamal reads them from your local machine or a secrets manager.

Monitoring

After deploying, you can check on your app:

kamal app logs        # View application logs
kamal app details     # Container status
kamal audit           # Deployment history

This Is a Demo

You're looking at a deployed RailsFast app right now. This exact deployment flow is what brought this demo to life. Get RailsFast and deploy your own.