Read the manual for an in-depth discussion of all of the options available in theGemfile manual
Gemfileand how to use them.
Gemfiles require at least one gem source, in the form of the URL for a RubyGems server. Generate a Gemfile with the default rubygems.org source by running
bundle init. If you can, use
httpsso your connection to the rubygems.org server will be verified with SSL.
source 'https://rubygems.org' # Gems here
If you want to pick up gems from a different source, make sure to wrap the extra sources in a block. Multiple global source lines are a security risk and should not be used as they can lead to gems being installed from unintended sources.
source 'https://rubygems.org' # Gems here source 'https://gems.example.com' do # Gems from the alternative source here end
Some gem sources require a username and password. Use
bundle configto set the username and password for any sources that need it. The command must be run once on each computer that will install the Gemfile, but this keeps the credentials from being stored in plain text in version control.
$ bundle config https://gems.example.com/ user:password
For some sources, like a company Gemfury account, it may be easier to simply include the credentials in the Gemfile as part of the source URL.
Credentials in the source URL will take precedence over credentials set using
Declare the gems that you need, including version numbers. Specify versions using the same syntax that RubyGems supports for dependencies.
gem 'nokogiri' gem 'rails', '5.0.0' gem 'rack', '>=1.0' gem 'thin', '~>1.1'
Most of the version specifiers, likeRubyGems version specifiers
>= 1.0, are self-explanatory. The specifier
~>has a special meaning, best shown by example.
~> 2.0.3is identical to
~> 2.1is identical to
~> 2.2.betawill match prerelease versions like
~> 0is identical to
If a gem's main file is different than the gem name, specify how to require it.
gem 'rack-cache', :require => 'rack/cache' gem 'sqlite3'
:require => falseto prevent bundler from requiring the gem, but still install it and maintain dependencies.
gem 'rspec', :require => false gem 'sqlite3'
In order to require gems in yourLearn More: Bundler.require
Gemfile, you will need to call
Bundler.requirein your application.
If some of your gems need to be fetched from a private gem server, this default source can be overridden for those gems. For a gem server that contains a single gem, it is easiest to use the
:sourceoption on that gem.
gem 'my_gem', '1.0', :source => 'https://gems.example.com'
If several gems come from the same server, you can use a
sourceblock to group them together.
source 'https://gems.example.com' do gem 'my_gem', '1.0' gem 'another_gem', '1.2.1' end
Credentials for gem servers can be specified either in the URL or using
bundle config, as described above.
Git repositories are also valid gem sources, as long as the repo contains one or more valid gems. Specify what to check out with
:ref. The default is the
gem 'nokogiri', :git => 'https://github.com/tenderlove/nokogiri.git', :branch => '1.4'
If the git repository does not contain aLearn More: Git
.gemspecfile, bundler will create a simple one, without any dependencies, executables or C extensions. This may work for simple gems, but not work for others. If there is no .gemspec, you probably shouldn't use the gem from git.
If you would like to use an unpacked gem directly from the filesystem, simply set the
:pathoption to the path containing the gem's files.
gem 'extracted_library', :path => './vendor/extracted_library'
If you would like to use multiple local gems directly from the filesystem, you can set a global `path` option to the path containing the gem's files. This will automatically load gemspec files from subdirectories.
path 'components' do gem 'admin_ui' gem 'public_ui' end
Dependencies can be placed into groups. Groups can be ignored at install-time (using
--without) or required all at once (using
Learn More: Groups
gem 'wirble', :group => :development gem 'debugger', :group => [:development, :test] group :test do gem 'rspec' end
You can specify the required version of Ruby in the
ruby. If the
Gemfileis loaded on a different Ruby version, Bundler will raise an exception with an explanation.
What this means is that this app has a dependency to a Ruby VM that is ABI compatible with 1.9.3. If the version check does not match, Bundler will raise an exception. This will ensure the running code matches. You can be more specific with the
Learn More: Ruby Directive
ruby '1.9.3', :engine => 'jruby', :engine_version => '1.6.7'