pumatra.rb

require 'sinatra/base'
require 'puma'
require 'rack'
require 'rack/server'


# Our simple hello-world app
class HelloApp < Sinatra::Base
    configure do
        set :server, :puma
    end

    get '/hello' do
        puts "/hello called"
        'Hello World'
    end

end

Rack::Server.start({
    :app => HelloApp.new,
    :server => 'puma'
})