gemfile - Man Page

Some gem sources require a username and password. Use bundle config(1) bundle-config.1.html to set the username and password for any of the 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 gems.example.com user:password

For some sources, like a company Gemfury account, it may be easier to include the credentials in the Gemfile as part of the source URL.

source "https://user:password@gems.example.com"

Credentials in the source URL will take precedence over credentials set using config.

The version of Ruby that your application requires. If your application requires an alternate Ruby engine, such as JRuby, TruffleRuby, etc., this should be the Ruby version that the engine is compatible with.

ruby "3.1.2"

If you wish to derive your Ruby version from a version file (ie .ruby-version), you can use the file option instead.

ruby file: ".ruby-version"

The version file should conform to any of the following formats:

• 3.1.2 (.ruby-version)
• ruby 3.1.2 (.tool-versions, read: https://asdf-vm.com/manage/configuration.html#tool-versions)

Each application may specify a Ruby engine. If an engine is specified, an engine version must also be specified.

What exactly is an Engine?

• A Ruby engine is an implementation of the Ruby language.
• For background: the reference or original implementation of the Ruby programming language is called Matz's Ruby Interpreter https://en.wikipedia.org/wiki/Ruby_MRI, or MRI for short. This is named after Ruby creator Yukihiro Matsumoto, also known as Matz. MRI is also known as CRuby, because it is written in C. MRI is the most widely used Ruby engine.
• Other implementations https://www.ruby-lang.org/en/about/ of Ruby exist. Some of the more well-known implementations include JRuby https://www.jruby.org/ and TruffleRuby https://www.graalvm.org/ruby/. Rubinius is an alternative implementation of Ruby written in Ruby. JRuby is an implementation of Ruby on the JVM, short for Java Virtual Machine. TruffleRuby is a Ruby implementation on the GraalVM, a language toolkit built on the JVM.

Each application may specify a Ruby engine version. If an engine version is specified, an engine must also be specified. If the engine is "ruby" the engine version specified must match the Ruby version.

ruby "2.6.8", engine: "jruby", engine_version: "9.3.8.0"

Each application may specify a Ruby patchlevel. Specifying the patchlevel has been meaningless since Ruby 2.1.0 was released as the patchlevel is now uniquely determined by a combination of major, minor, and teeny version numbers.

This option was implemented in Bundler 1.4.0 for Ruby 2.0 or earlier.

ruby "3.1.2", patchlevel: "20"

For each gem requirement, list a single gem line.

gem "nokogiri"

Each gem MAY have one or more version specifiers.

gem "nokogiri", ">= 1.4.2"
gem "RedCloth", ">= 4.1.0", "< 4.2.0"

Each gem MAY specify files that should be used when autorequiring via Bundler.require. You may pass an array with multiple files or true if the file you want required has the same name as gem or false to prevent any file from being autorequired.

gem "redis", require: ["redis/connection/hiredis", "redis"]
gem "webmock", require: false
gem "byebug", require: true

The argument defaults to the name of the gem. For example, these are identical:

gem "nokogiri"
gem "nokogiri", require: "nokogiri"
gem "nokogiri", require: true

Each gem MAY specify membership in one or more groups. Any gem that does not specify membership in any group is placed in the default group.

gem "rspec", group: :test
gem "wirble", groups: [:development, :test]

The Bundler runtime allows its two main methods, Bundler.setup and Bundler.require, to limit their impact to particular groups.

# setup adds gems to Ruby's load path
Bundler.setup                    # defaults to all groups
require "bundler/setup"          # same as Bundler.setup
Bundler.setup(:default)          # only set up the _default_ group
Bundler.setup(:test)             # only set up the _test_ group (but `not` _default_)
Bundler.setup(:default, :test)   # set up the _default_ and _test_ groups, but no others

# require requires all of the gems in the specified groups
Bundler.require                  # defaults to the _default_ group
Bundler.require(:default)        # identical
Bundler.require(:default, :test) # requires the _default_ and _test_ groups
Bundler.require(:test)           # requires the _test_ group

The Bundler CLI allows you to specify a list of groups whose gems bundle install should not install with the without configuration.

To specify multiple groups to ignore, specify a list of groups separated by spaces.

bundle config set --local without test
bundle config set --local without development test

Also, calling Bundler.setup with no parameters, or calling require "bundler/setup" will setup all groups except for the ones you excluded via --without (since they are not available).

Note that on bundle install, bundler downloads and evaluates all gems, in order to create a single canonical list of all of the required gems and their dependencies. This means that you cannot list different versions of the same gems in different groups. For more details, see Understanding Bundler https://bundler.io/rationale.html.

If a gem should only be used in a particular platform or set of platforms, you can specify them. Platforms are essentially identical to groups, except that you do not need to use the --without install-time flag to exclude groups of gems for other platforms.

There are a number of Gemfile platforms:

ruby

C Ruby (MRI), Rubinius, or TruffleRuby, but not Windows

mri

C Ruby (MRI) only, but not Windows

windows

Windows C Ruby (MRI), including RubyInstaller 32-bit and 64-bit versions

mswin

Windows C Ruby (MRI), including RubyInstaller 32-bit versions

mswin64

Windows C Ruby (MRI), including RubyInstaller 64-bit versions

rbx

Rubinius

jruby

JRuby

truffleruby

TruffleRuby

On platforms ruby, mri, mswin, mswin64, and windows, you may additionally specify a version by appending the major and minor version numbers without a delimiter. For example, to specify that a gem should only be used on platform ruby version 3.1, use:

ruby_31

As with groups (above), you may specify one or more platforms:

gem "weakling",   platforms: :jruby
gem "ruby-debug", platforms: :mri_31
gem "nokogiri",   platforms: [:windows_31, :jruby]

All operations involving groups (bundle install bundle-install.1.html, Bundler.setup, Bundler.require) behave exactly the same as if any groups not matching the current platform were explicitly excluded.

The following platform values are deprecated and should be replaced with windows:

• mswin, mswin64, mingw32, x64_mingw

Note that, while unfortunately using the same terminology, the values of this option are different from the values that bundle lock --add-platform can take. The values of this option are more closer to "Ruby Implementation" while the values that bundle lock --add-platform understands are more related to OS and architecture of the different systems where your lockfile will be used.

If you always want the pure ruby variant of a gem to be chosen over platform specific variants, you can use the force_ruby_platform option:

gem "ffi", force_ruby_platform: true

This can be handy (assuming the pure ruby variant works fine) when:

• You're having issues with the platform specific variant.
• The platform specific variant does not yet support a newer ruby (and thus has a required_ruby_version upper bound), but you still want your Gemfile{.lock} files to resolve under that ruby.

You can select an alternate RubyGems repository for a gem using the ':source' option.

gem "some_internal_gem", source: "https://gems.example.com"

This forces the gem to be loaded from this source and ignores the global source declared at the top level of the file. If the gem does not exist in this source, it will not be installed.

Bundler will search for child dependencies of this gem by first looking in the source selected for the parent, but if they are not found there, it will fall back on the global source.

Note about a behavior of the feature deprecated in Bundler 1.13: Selecting a specific source repository this way also suppresses the ambiguous gem warning described above in Global Source.

Using the :source option for an individual gem will also make that source available as a possible global source for any other gems which do not specify explicit sources. Thus, when adding gems with explicit sources, it is recommended that you also ensure all other gems in the Gemfile are using explicit sources.

If necessary, you can specify that a gem is located at a particular git repository using the :git parameter. The repository can be accessed via several protocols:

HTTP(S)

gem "rails", git: "https://github.com/rails/rails.git"

SSH

gem "rails", git: "git@github.com:rails/rails.git"

git

gem "rails", git: "git://github.com/rails/rails.git"

If using SSH, the user that you use to run bundle install MUST have the appropriate keys available in their $HOME/.ssh.

NOTE: http:// and git:// URLs should be avoided if at all possible. These protocols are unauthenticated, so a man-in-the-middle attacker can deliver malicious code and compromise your system. HTTPS and SSH are strongly preferred.

The group, platforms, and require options are available and behave exactly the same as they would for a normal gem.

A git repository SHOULD have at least one file, at the root of the directory containing the gem, with the extension .gemspec. This file MUST contain a valid gem specification, as expected by the gem build command.

If a git repository does not have a .gemspec, bundler will attempt to create one, but it will not contain any dependencies, executables, or C extension compilation instructions. As a result, it may fail to properly integrate into your application.

If a git repository does have a .gemspec for the gem you attached it to, a version specifier, if provided, means that the git repository is only valid if the .gemspec specifies a version matching the version specifier. If not, bundler will print a warning.

gem "rails", "2.3.8", git: "https://github.com/rails/rails.git"
# bundle install will fail, because the .gemspec in the rails
# repository's master branch specifies version 3.0.0

If a git repository does not have a .gemspec for the gem you attached it to, a version specifier MUST be provided. Bundler will use this version in the simple .gemspec it creates.

Git repositories support a number of additional options.

branch, tag, and ref

You MUST only specify at most one of these options. The default is branch: "master". For example:

gem "rails", git: "https://github.com/rails/rails.git", branch: "5-0-stable"

gem "rails", git: "https://github.com/rails/rails.git", tag: "v5.0.0"

gem "rails", git: "https://github.com/rails/rails.git", ref: "4aded"

submodules

For reference, a git submodule https://git-scm.com/book/en/v2/Git-Tools-Submodules lets you have another git repository within a subfolder of your repository. Specify submodules: true to cause bundler to expand any submodules included in the git repository

If a git repository contains multiple .gemspecs, each .gemspec represents a gem located at the same place in the file system as the .gemspec.

|~rails                   [git root]
| |-rails.gemspec         [rails gem located here]
|~actionpack
| |-actionpack.gemspec    [actionpack gem located here]
|~activesupport
| |-activesupport.gemspec [activesupport gem located here]
|...

To install a gem located in a git repository, bundler changes to the directory containing the gemspec, runs gem build name.gemspec and then installs the resulting gem. The gem build command, which comes standard with Rubygems, evaluates the .gemspec in the context of the directory in which it is located.

A custom git source can be defined via the git_source method. Provide the source's name as an argument, and a block which receives a single argument and interpolates it into a string to return the full repo address:

git_source(:stash){ |repo_name| "https://stash.corp.acme.pl/#{repo_name}.git" }
gem 'rails', stash: 'forks/rails'

In addition, if you wish to choose a specific branch:

gem "rails", stash: "forks/rails", branch: "branch_name"

NOTE: This shorthand should be avoided until Bundler 2.0, since it currently expands to an insecure git:// URL. This allows a man-in-the-middle attacker to compromise your system.

If the git repository you want to use is hosted on GitHub and is public, you can use the :github shorthand to specify the github username and repository name (without the trailing ".git"), separated by a slash. If both the username and repository name are the same, you can omit one.

gem "rails", github: "rails/rails"
gem "rails", github: "rails"

Are both equivalent to

gem "rails", git: "https://github.com/rails/rails.git"

Since the github method is a specialization of git_source, it accepts a :branch named argument.

You can also directly pass a pull request URL:

gem "rails", github: "https://github.com/rails/rails/pull/43753"

Which is equivalent to:

gem "rails", github: "rails/rails", branch: "refs/pull/43753/head"

If the git repository you want to use is hosted as a GitHub Gist and is public, you can use the :gist shorthand to specify the gist identifier (without the trailing ".git").

gem "the_hatch", gist: "4815162342"

Is equivalent to:

gem "the_hatch", git: "https://gist.github.com/4815162342.git"

Since the gist method is a specialization of git_source, it accepts a :branch named argument.

If the git repository you want to use is hosted on Bitbucket and is public, you can use the :bitbucket shorthand to specify the bitbucket username and repository name (without the trailing ".git"), separated by a slash. If both the username and repository name are the same, you can omit one.

gem "rails", bitbucket: "rails/rails"
gem "rails", bitbucket: "rails"

Are both equivalent to

gem "rails", git: "https://rails@bitbucket.org/rails/rails.git"

Since the bitbucket method is a specialization of git_source, it accepts a :branch named argument.

You can specify that a gem is located in a particular location on the file system. Relative paths are resolved relative to the directory containing the Gemfile.

Similar to the semantics of the :git option, the :path option requires that the directory in question either contains a .gemspec for the gem, or that you specify an explicit version that bundler should use.

Unlike :git, bundler does not compile C extensions for gems specified as paths.

gem "rails", path: "vendor/rails"

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