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This basic workspace demonstrates how to create simple Hello-world application, install Rails, manage multiple Ruby versions with Rbenv and install dependencies with Bundler.


Open terminal, and check Ruby version

ruby -v

Install Rails - a web application development framework written in the Ruby programming language.

gem install rails

Check version

rails --version

Hello world

Open VS-code, and create file http_server.rb

# http_server.rb
require 'socket'
server = 8040

while session = server.accept
  request = session.gets
  puts request

  session.print "HTTP/1.1 200\r\n" # 1
  session.print "Content-Type: text/html\r\n" # 2
  session.print "\r\n" # 3
  session.print "Hello world! The time is #{}" #4


Now open terminal, and execute to serve simple server

ruby http_server.rb

Open Quickstart page, go to "My apps" and use port 8040 shortcut to open your web app

Workspace collage


Bundler provides a consistent environment for Ruby projects by tracking and installing the exact gems and versions that are needed.

Create file Gemfile with the following content

source ''
gem 'nokogiri'
gem 'rack', '~> 2.0.1'
gem 'rspec'

Install all of the required gems

bundle install


Use rbenv to pick a Ruby version for your application and guarantee that your development environment matches production.

List available versions, and install another one

rbenv install --list
rbenv install 3.0.4

Lists all Ruby versions known to rbenv, and shows an asterisk next to the currently active version.

rbenv versions

global environment

Change global Ruby (for all folders)

rbenv global 3.0.4

local environment (specific folder)

Chose local Ruby environment for this specific folder

rbenv local 3.0.4