Deploy a Ruby on Rails App

This guide explains how to deploy a Ruby on Rails application on Koyeb using:

Git-driven deployment to automatically build and deploy a new version of your application each time a change is detected on your branch.
Pre-built containers you can deploy from any public or private registry.

To successfully follow this documentation, you will need to have a Koyeb account. You can optionally install the Koyeb CLI if you prefer to follow this guide without leaving the terminal.

You can deploy and preview the sample Ruby on Rails application that we will run on Koyeb in this guide using the Deploy to Koyeb button below.

You can access the repository used for this documentation here.

Create the Rails app

Get started by creating a minimalistic Rails application that we will deploy on Koyeb. You will need Ruby and Rails installed on your machine.

In your terminal, run the following commands to create a new Rails application:

$ rails new example-rails --minimal

This will create a new minimum Rails application skeleton in the example-rails directory with just Active Record, Action Pack, Active Support, Railties, and the bare necessity support gems.

Create a new Rails controller by running the following command:

rails generate controller HelloKoyeb index

Then, open the config/routes.rb file and edit as shown below to indicate Rails GET / requests are mapped to the index action of the HelloKoyeb controller.

Rails.application.routes.draw do
  get 'hello_koyeb/index'

+ root 'hello_world#index'
  # Define your application routes per the DSL in https://guides.rubyonrails.org/routing.html

  # Defines the root path route ("/")
  # root "articles#index"
end

Run the Rails app locally

Launch the application locally to make sure everything is running as expected.

cd example-rails
rails server

You can now access the application at http://localhost:3000.

Deploy the Rails app on Koyeb using git-driven deployment

The rails new command we ran previously initialized a new git repository in the example-rails directory.

We will use this repository to version the application code and push the changes to a GitHub repository. If you don't have an existing GitHub repository to push the code to, you can create a new one and run the following commands to commit and push changes to your GitHub repository:

git add .
git commit -m "Initial commit"
git remote add origin git@github.com:<YOUR_GITHUB_USERNAME>/<YOUR_REPOSITORY_NAME>.git
git push -u origin main

Via the Koyeb control panel

To deploy the Rails app on Koyeb using the control panel, follow the steps below:

Create a new Koyeb App named example-rails
Select GitHub as the deployment option
Choose the GitHub repository and branch contaning your application code
Name your service, for instance rails-service
Click the Create service button.

A Koyeb App and Service have been created. Your application is now going to be built and deployed on Koyeb. Once the build is complete, you will be able to access your application running on Koyeb by clicking the URL ending with .koyeb.app.

Via Koyeb CLI

To deploy the Rails app on Koyeb using the Koyeb CLI, run the following command in your terminal:

koyeb app init example-rails \
  --git github.com/<YOUR_GITHUB_USERNAME>/<YOUR_REPOSITORY_NAME> \
  --git-branch main \
  --ports 8080:http \
  --routes /:8080 \
  --env PORT=8080

Make sure to replace <YOUR_GITHUB_USERNAME>/<YOUR_REPOSITORY_NAME> with your GitHub username and repository name.

Access deployment logs

To track the app deployment and visualize build logs, execute the following command:

koyeb service logs example-rails/example-rails -t build

Access your app

Once the deployment of your application has finished, you can retrieve the public domain to access your application by running the following command:

$ koyeb app get example-rails
ID      	NAME         	DOMAINS                          	CREATED AT
55d75993	example-rails	["example-rails-myorg.koyeb.app"]	20 Sep 22 09:55 UTC

Access runtime logs

With your app running, you can track the runtime logs by running the following command:

koyeb service logs example-rails/example-rails -t runtime

Deploy the Rails app on Koyeb using a pre-built container

Alternatively to using git-driven deployment, you can deploy a pre-built container from any public or private registry. This can be useful if your application needs specific system dependencies or you need more control over how the build is performed.

To dockerize the Rails application, create a Dockerfile in your project root directory and copy the content below:

FROM ruby:3-alpine

WORKDIR /app
COPY . .

RUN gem install bundler
RUN bundle install
ENV RAILS_ENV=production
RUN bundle exec rails assets:precompile
EXPOSE 3000
CMD ["rails", "server", "-b", "0.0.0.0"]

The Dockerfile above provides the minimum requirements to run the Rails application. You can easily extend it depending on your needs.

To build and push the Docker image to a registry and deploy it on Koyeb, refer to the Deploy an app from a Docker image.