Install Rails 5.2.0 API Only application with latest Ruby 2.5.1

Check for the new ruby and rails versions

Here we are going to install Ruby – 2.5.1 & Rails – 5.2.0 (API only application)

Get rbenv into action
If you are not installed rbenv, you can install it from here:
After the installation make sure that, your $PATH has included rbenv/shims path. Else rbenv will not work.

1. $ rbenv install --list # Gets the list of ruby versions available

$ rbenv install 2.5.1

ruby-build: definition not found: 2.5.1

The following versions contain `2.5.1' in the name:

See all available versions with `rbenv install --list'.

If the version you need is missing, try upgrading ruby-build:

  brew update && brew upgrade ruby-build


rbenv cannot find the version: 2.5.1

Upgrade ruby-build

Mac OSX:

$ brew upgrade ruby-build --HEAD

Now install ruby 2.5.1

$ rbenv install 2.5.1

Create a new gemset:

Rbenv gemset is a separate script and not coming with rbenv. If you are not installed this, you can install it from here:

$ rbenv gemset create 2.5.1 demo-app
That set up a directory for you in ~/.rbenv/versions/2.5.1/gemsets/demo-app

Set the ruby version to the newest

$ rbenv local 2.5.1

$ rbenv version
=> 2.5.1

    Activate New Gemset

For activating a gemset we need to create a .rbenv-gemsets file in the current directory.

$ touch .rbenv-gemsets
$ echo demo-app > .rbenv-gemsets

Check active gemset:

$ rbenv gemset active

Install Rails 5.2.0 API only Application

$ gem install rails -v '5.2.0'

$ rails -v
Rails 5.2.0

Later we can delete this .rbenv-gemsets file and add a new file named ‘.ruby-gemset’ in the rails project directory. I cannot find any other option for doing this. If anyone know more about this, please give a comment. I appreciate that.

Create a New Rails app

$ rails new demo-app  --api -T # skips the documentation

-T to exclude Minitest – the default testing framework if you are planning to use RSpec to test your API.

Rspec test framework:

You can use the following with Rspec.
Shoulda Matchers:
Collection of testing matchers extracted from Shoulda (

Database Cleaner:
Strategies for cleaning databases in Ruby. Can be used to ensure a clean state for testing

A library for generating fake data such as names, addresses, and phone numbers.

use option: –no-rdoc –no-ri # skips the documentation

Remove Rbenv Gemset and add Ruby gems file

$ rm .rbenv-gemsets

$ cd demo-app
$ touch .ruby-gemset
$ echo demo-app > .ruby-gemset
$ rails s
=> Booting Puma
=> Rails 5.2.0 application starting in development
=> Run `rails server -h` for more startup options
Puma starting in single mode...
* Version 3.11.4 (ruby 2.5.1-p57), codename: Love Song
* Min threads: 5, max threads: 5
* Environment: development
* Listening on tcp://
Use Ctrl-C to stop

Goto http://localhost:3000/


Done! Lets go…


Author: Abhilash

Hi, this is Abhilash - Senior Programmer Analyst at CoMakeIT, specialised on web programming. Mainly working on Ruby On Rails platform since 2010.

One thought on “Install Rails 5.2.0 API Only application with latest Ruby 2.5.1”

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s