# Supported tags and respective `Dockerfile` links

- [`4.2.0`, `4.2`, `4`, `latest` (*Dockerfile*)](https://github.com/docker-library/rails/blob/3c87a6cf32d01204b95ba12a266d13c8c32e5358/Dockerfile)
- [`onbuild` (*onbuild/Dockerfile*)](https://github.com/docker-library/rails/blob/3c87a6cf32d01204b95ba12a266d13c8c32e5358/onbuild/Dockerfile)

For more information about this image and its history, please see the [relevant
manifest file
(`library/rails`)](https://github.com/docker-library/official-images/blob/master/library/rails)
in the [`docker-library/official-images` GitHub
repo](https://github.com/docker-library/official-images).

# What is Ruby on Rails?

Ruby on Rails or, simply, Rails is an open source web application framework
which runs on the Ruby programming language. It is a full-stack framework. This
means that "out of the box", Rails can create pages and applications that gather
information from a web server, talk to or query a database, and render
templates. As a result, Rails features a routing system that is independent of
the web server.

> [wikipedia.org/wiki/Ruby_on_Rails](https://en.wikipedia.org/wiki/Ruby_on_Rails)

![logo](https://raw.githubusercontent.com/docker-library/docs/master/rails/logo.png)

# How to use this image

## Create a `Dockerfile` in your Rails app project

    FROM rails:onbuild

Put this file in the root of your app, next to the `Gemfile`.

This image includes multiple `ONBUILD` triggers which should cover most
applications. The build will `COPY . /usr/src/app`, `RUN bundle install`,
`EXPOSE 3000`, and set the default command to `rails server`.

You can then build and run the Docker image:

    docker build -t my-rails-app .
    docker run --name some-rails-app -d my-rails-app

You can test it by visiting `http://container-ip:3000` in a browser or, if you
need access outside the host, on port 8080:

    docker run --name some-rails-app -p 8080:3000 -d my-rails-app

You can then go to `http://localhost:8080` or `http://host-ip:8080` in a
browser.

### Generate a `Gemfile.lock`

The `onbuid` tag expects a `Gemfile.lock` in your app directory. This `docker
run` will help you generate one. Run it in the root of your app, next to the
`Gemfile`:

    docker run --rm -v "$(pwd)":/usr/src/app -w /usr/src/app ruby:2.1 bundle install

## Bootstrap a new Rails application

If you want to generate the scaffolding for a new Rails project, you can do the
following:

    docker run -it --rm --user "$(id -u):$(id -g)" -v "$(pwd)":/usr/src/app -w /usr/src/app rails rails new webapp

This will create a sub-directory named `webapp` inside your current directory.

# License

View [license information](https://github.com/rails/rails#license)
for the software contained in this image.

# Supported Docker versions

This image is officially supported on Docker version 1.4.1.

Support for older versions (down to 1.0) is provided on a best-effort basis.

# User Feedback

## Issues

If you have any problems with or questions about this image, please contact us
 through a [GitHub issue](https://github.com/docker-library/rails/issues).

You can also reach many of the official image maintainers via the
`#docker-library` IRC channel on [Freenode](https://freenode.net).

## Contributing

You are invited to contribute new features, fixes, or updates, large or small;
we are always thrilled to receive pull requests, and do our best to process them
as fast as we can.

Before you start to code, we recommend discussing your plans 
through a [GitHub issue](https://github.com/docker-library/rails/issues), especially for more ambitious
contributions. This gives other contributors a chance to point you in the right
direction, give you feedback on your design, and help you find out if someone
else is working on the same thing.