Rails Environment & Configuration


  • Gem and RubyGem 
  • Gemfile and Gemfile.lock 
  • Bundler 
  • Environments 
  • Configuration 
  • Initializers 
  • Rake

Gem & RubyGem (per system)

What is Gem and RubyGem? 

  • Gem is a standard package format for Ruby libraries 
    • In the same way “jar” and “war” are standard package formats for Java libraries 
  • In Ruby/Rails world, a feature is built as a gem and there are tons of 3rd-party gems you can use right away 
    • Security, testing, performance, ... 
  • You can create your own custom gems or extend existing gems 
  • RubyGem is package manager for the Ruby programming language 
    • Manage the installation/uninstallation of gems (per your system) 
    • RubyGem comes with Ruby 1.9+ 
    • You interact with RubyGem with “gem” command


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