Application originated from article: https://blog.botreetechnologies.com/setting-up-ruby-on-rails-5-app-with-mongodb-in-10-minutes-3c400c055262; they perform a linux information if you are not a mac user.
brew install mongodb
# Follow instructions from homebrew for further install instructions.
brew services start mongodb
# Restart your computer.
bundle install
rake db:create
open http://localhost:3000/articles
rails srails new my_mongo_app --skip-active-record
echo "gem 'mongoid', '~> 6.0'
gem 'bson_ext'" >> Gemfile
bundle install
rails g mongoid:config
rake db:create
rails g scaffold article name:string content:text
open http://localhost:3000/articles
rails s