Sinatra rack middleware hijacks '/' root url

Question

I'm trying to use a Sinatra app as middleware in my Rails app.

I've tested a basic Sinatra app in the /lib folder of the Rails app, used the middleware and set a route. That worked fine.

What I want to be able to do is extract the Sinatra app and include it as a gem. That way I can run the Sinatra app independently, or use it in multiple Rails apps.

Sinatra App

# myrackapp/lib/myrackapp.rb
module Myrackapp
  class Application < Sinatra::Base

    set :root, File.dirname(__FILE__)

    get "/" do
      "Rack Home"
    end

    get '/rackroute' do
      "Hello, Rack Page"
    end

    end
end

Myrackapp also has a gemspec – nothing interesting there, but I can post if necessary.

Rails App

# Gemfile
gem 'myrackapp', path: "/Users/gareth/Code/myrackapp"

-

# config/application.rb
module Myrailsapp
  class Application < Rails::Application
    ...
    config.middleware.use "Myrackapp::Application"
  end
end

-

# config.routes.rb
root :to => 'pages#show', :id => 'home'
mount Myrackapp::Application => "/rackapp"

Here's my rake middleware output:

    rake middleware
    use ActionDispatch::Static
    use Rack::Lock
    use #<ActiveSupport::Cache::Strategy::LocalCache::Middleware:0x141ded4>
    use Rack::Runtime
    use Rack::MethodOverride
    use ActionDispatch::RequestId
    use Rails::Rack::Logger
    use ActionDispatch::ShowExceptions
    use ActionDispatch::DebugExceptions
    use ActionDispatch::RemoteIp
    use ActionDispatch::Reloader
    use ActionDispatch::Callbacks
    use ActiveRecord::ConnectionAdapters::ConnectionManagement
    use ActiveRecord::QueryCache
    use ActionDispatch::Cookies
    use ActionDispatch::Session::CookieStore
    use ActionDispatch::Flash
    use ActionDispatch::ParamsParser
    use ActionDispatch::Head
    use Rack::ConditionalGet
    use Rack::ETag
    use ActionDispatch::BestStandardsSupport
    use Myrackapp::Application
    run Myrailsapp::Application.routes

When I go to http://myapp.dev/rackapp I get Myrackapp's root path - correct behaviour

When I go to http://myapp.dev/rackapp/rackroute I get Myrackapp's /rackroute path - again, correct behaviour

The Problem

When I go to http://myapp.dev in the browser I get directed to the Myrackapp's root path.

When I included the Sinatra app directly in my Rails app visiting http://myapp.dev rendered the correct pages#show action.

What can I do to get the Sinatra app to not hijack the root path of Rails?

Answer 1

You don't actually need to include the Sinatra app as middleware to do what you want.

Including it as middleware will mean that all requests are routed through it, which you don't want/need in order to make it supply the routes.

If you want to add the routes automatically when you include the gem in a rails app you could add a railtie that adds routes to the application. I can't remember off the top of my head what that looks like, but it should be pretty straightforward.