Sinatra + Bundler? - ruby

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

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 2

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 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