What is gemfile.lock

What is Gemfile.lock? or What is the difference between Gemfile and Gemfile.lock? These are the common questions that you come across while starting development with Rails project.

What is Gemfile?

  • Gemfile is the file in which you can mention which gems (kind of Third Party libraries) that you want to use for your Rails application
  • Gemfile lists the gems that you want to use for your development
  • Syntax:
gem 'rails'
  • This mentions that gem with name ‘rails’ has to be used in Project context
  • Whenever you bundle install, then bundler finds the gems listed in the Gemfile and it installs latest stable version for the gems listed in the Gemfile
  • You can specify which version to be used for the rails development:
gem 'rails', '3.0.5'
    • This will install the specific version of the rails i.e. version 3.0.5
  • You can read more regarding Gemfile here

What is Gemfile.lock?

  • Gemfile.lock is created when bundler installs the specific version for the gems that are listed in Gemfile
  • It records the version of the gem and name of the gem in file Gemfile.lock
  • Thus, Gemfile.lock contains actual gem name with version with which your application was configured by the bundler
  • Thus, Gemfile.lock is the file with actual gem version configuration
  • Thus answer to what is gemfile.lock is - File with gems configured for your Rails applications along with the exact versions
  • This file can be updated when you change gems listed in the Gemfile and also updating it using the bundler