How can I use unicorn as "rails s"?

Question

A new Rails project's Gemfile shows:

# Use unicorn as the app server
gem 'unicorn'

rails s --help shows:

Usage: rails server [mongrel, thin, etc] [options]

Yet, doing:

rails s unicorn

I get:

/Users/patrick/.rvm/gems/ruby-1.9.3-head@keynote/gems/rack-1.4.5/lib/rack/handler.rb:63:in `require': cannot load such file -- rack/handler/unicorn (LoadError)
from /Users/patrick/.rvm/gems/ruby-1.9.3-head@keynote/gems/rack-1.4.5/lib/rack/handler.rb:63:in `try_require'
from /Users/patrick/.rvm/gems/ruby-1.9.3-head@keynote/gems/rack-1.4.5/lib/rack/handler.rb:16:in `get'
from /Users/patrick/.rvm/gems/ruby-1.9.3-head@keynote/gems/rack-1.4.5/lib/rack/server.rb:272:in `server'
from /Users/patrick/.rvm/gems/ruby-1.9.3-head@keynote/gems/railties-3.2.13/lib/rails/commands/server.rb:59:in `start'
from /Users/patrick/.rvm/gems/ruby-1.9.3-head@keynote/gems/railties-3.2.13/lib/rails/commands.rb:55:in `block in <top (required)>'
from /Users/patrick/.rvm/gems/ruby-1.9.3-head@keynote/gems/railties-3.2.13/lib/rails/commands.rb:50:in `tap'
from /Users/patrick/.rvm/gems/ruby-1.9.3-head@keynote/gems/railties-3.2.13/lib/rails/commands.rb:50:in `<top (required)>'
from script/rails:6:in `require'
from script/rails:6:in `<main>'

I've used unicorn in the past on other projects, but always had to run the unicorn command and specify a config file which is a bit of a pain. I am wondering how I can just simply make it work by using rails s...

Is this possible?

Solution 1

It looks like the unicorn-rails gem that @Dogbert mentioned can actually be used to make Unicorn the rails server handler.

Simply include gem "unicorn-rails" (and for Rails 4.2.4, gem "rack-handlers") in your Gemfile, run bundle install to install the gem, then you can run:

$ rails server unicorn

Although once unicorn-rails is installed, Unicorn should be the default app server so you could also just run rails server and it should use Unicorn (assuming you don't also have Thin or Mongrel in your Gemfile, in which case they may conflict and you might want to remove the ones you're not using).

Solution 2

A better option might just be to run the unicorn server directly.

bundle exec unicorn -p 3000 # default port is 8080

Solution 3

gem 'rack-handlers'

rails server unicorn

Comments

[patrick]

I find it very interesting that the gemfile has 'unicorn' rather than 'unicorn_rails' as a suggestion. I also find it interesting that this webpage says: "unicorn_rails was made to be an easier transition for users of pre-Rack versions of Rails. The manpage encourages Rails 3 users to use plain unicorn instead." blog.engineyard.com/2010/…

[Stuart M]

Which Gemfile are you seeing unicorn in? I suggested adding the unicorn-rails gem to your Gemfile.

[Eric Caron]

The other beauty of using rack-handlers is that it autoloads the config/unicorn.rb file.

[Evan]

For Rails 4.2.4, this first requires adding gem 'rack-handlers' to your Gemfile along with gem 'unicorn'

[Huzaifa Saifuddin]

How can i increase Workers?