Rails 5 will be the easiest release ever to get running on Heroku. You can get it going in just five lines:
$ rails new myapp -d postgresql $ cd myapp $ git init . ; git add . ; git commit -m first $ heroku create $ git push heroku master
These five lines (and a view or two) are all you need to get a Rails 5 app working on Heroku — there are no special gems you need to install, or flags you must toggle. Let's take a peek under the hood, and explore the interfaces baked right into Rails 5 that make it easy to deploy your app on any modern container-based platform.
Production Web Server as the Default
Before Rails 5, the default web server that you get when you run $ rails server
is...