How to use puma in production mode by set production environment?

Question

I made a little Sinatra app. In my Gemfile add gem 'puma' in the production group

group :production do
    gem 'puma'
    gem 'dm-postgres-adapter'
end

And I set production mode in config.ru

set :environment, :production

But after I run backup, the default webrick web server run instead. How can I solve this?

Solution

Just use puma :)

$ puma config.ru

You can run your Sinatra application with Puma from the command line like this:

$ ruby app.rb -s Puma

Or you can configure your application to always use Puma:

require 'sinatra'
configure { set :server, :puma }

You can pass it as an option to rackup:

 $ rackup -s Puma

Alternatively, you can modify your config.ru to choose Puma by default, by adding the following as the first line:

 #\ -s puma