Sinatra + Bundler?

Question

I'm wondering how one can use Bundler with Sinatra. The idea is to use the gems that Bundler downloads inside the .gems folder.

Answer 1

I believe the best way is described here on EngineYard blog:

# This makes sure the bundled gems are in our $LOAD_PATH
require File.expand_path(File.join(File.dirname(__FILE__), 'vendor', 'gems', 'environment'))

# This actually requires the bundled gems
Bundler.require_env

class MyApp < Sinatra::Base
  # stuff
end

Answer 2

Inside your Sinatra app, you just have to require the bundler setup:

require "bundler/setup"
require "sinatra"

get "/" do
  "Hello world!"
end

Alternatively, if you don't want to add the additional require "bundler/setup" at the top of your app, you can instead invoke sinatra via bundle exec (e.g. bundle exec ruby myapp.rb)

This assumes that you have a Gemfile in the root of your application. It might look like this:

source "http://rubygems.org"

gem "sinatra"

This also assumes that you've already installed bundler (gem install bundler) and that you ran bundle install to install all the gem dependencies.

Answer 3

As my original answer was quite old but there seems to be still attention to this topic here's the latest version of bundler/sinatra setup which will cover most of the use case:

A minimal config.ru

require './my_sinatra_app'
run MySinatraApp

An environment env.rb file that requires all the bundled gems (also supports loading the current environment's group):

require 'bundler/setup'

APP_ENV = ENV["RACK_ENV"] || "development"

Bundler.require :default, APP_ENV.to_sym

Then your app file (requiring the environment) with your sinatra app (Sinatra::Base):

require_relative 'env'

class MyApp < Sinatra::Base
  get "/" do
    "hello world"
  end
end

Start your development server with rackup, and Sinatra will be loaded via Bundler, your app will be accessible from http://localhost:9292.

$ rackup

or bundle exec rackup if needed

Make sure you have a Gemfile like the following one and you run the bundle command before starting the app

source "https://rubygems.org"

gem "sinatra"

gem "puma" # a better rack server than the default webrick

Answer 4

+1 for the guide on the bundler website, but if you have a simple app and use Sinatra's dsl at the top level, then you need to do the following:

in your Gemfile (tell bundler not require sinatra):

gem 'sinatra', :require => false

and in the app's file (explicitly require sinatra):

require 'rubygems'
require 'bundler'
Bundler.require
require 'sinatra'

get '/' do
  'hello world'
end

Answer 5

To use bundler with a Sinatra application, you only need to do two things. First, create a Gemfile.

gem 'sinatra'

Then, set up your config.ru file to load the bundle before it loads your Sinatra app.

require 'rubygems'
require 'bundler'

Bundler.require

require './my_sinatra_app'
run MySinatraApp

Start your development server with rackup, and Sinatra will be loaded via Bundler.

rackup

source bundler docs