Instant Rails: Dockerized Rails Application Template

What Instant Rails is

Instant Rails is a Rails application template that comes with certain common tools, like Devise and RSpec, pre-installed.

Instant Rails is a special kind of Rails application template. Instant Rails will generate your application inside of a Docker container so that you don’t even need to have Ruby, Rails, PostgreSQL or anything else installed on your computer in order to generate a Rails app.

Why I created Instant Rails

I have a relatively frequent need to create “throwaway” Rails apps for educational purposes. I created Instant Rails to help me with two problems:

  • Even though it’s not that much work to create a new Rails application, it’s still too tedious to do all the Rails project initialization work every time I want a new project.
  • For students, it’s often too hard for them to get my projects set up on their computer (especially, often, the PostgreSQL-related parts).

A Dockerized application template helps solve both these problems.

How to use Instant Rails


In order to use Instant Rails, you must have Docker installed.

Usage instructions

First, clone the repo.

git clone
cd instant_rails

Then run the script.

./ your_app_name

This script will create a Rails application and start a Rails server.

Once the script finishes, you can visit localhost:3001 (note that the port is 3001, not 3000) and see your app running.

Get help

To get help, just open an issue or email me at


This project was inspired in part by Mike Rogers’ Docker/Rails template.