How to Deploy Ruby on Rails to Production with Docker and Kamal

Modern Rails Deployment with Kamal

Gone are the days of complex Capistrano scripts or expensive PaaS platforms. With Kamal, you can deploy Rails applications to any Linux server with Docker in minutes.

Step 1: Add Kamal

$ bundle add kamal
$ kamal init

Step 2: Configure deploy.yml

Set your server IPs, Docker registry, SSL settings, and environment variables in config/deploy.yml.

Step 3: Optimize Your Dockerfile

Use multi-stage builds to keep your production image small — build stage installs gems and precompiles assets, runtime stage copies only what's needed.

Step 4: Deploy

$ kamal setup    # First-time setup
$ kamal deploy   # Subsequent deploys

Kamal handles SSL certificate provisioning, container orchestration, and zero-downtime rolling deployments automatically.

Need help with your deployment strategy? Talk to our DevOps team.