GEMFILE(5) GEMFILE(5)

NAME

Gemfile - A format for describing gem dependencies for Ruby programs

SYNOPSIS

A Gemfile describes the gem dependencies required to execute associated
Ruby code.

Place the Gemfile in the root of the directory containing  the  associ-
ated  code.  For instance, in a Rails application, place the Gemfile in
the same directory as the Rakefile.

SYNTAX

A Gemfile is evaluated as Ruby code, in a context which makes available
a number of methods used to describe the gem requirements.

GLOBAL SOURCES (#source)

    At the top of the Gemfile, add a line for the Rubygems source that con-
    tains the gems listed in the Gemfile.

        source "https://rubygems.org"

    It is possible, but not recommended as of Bundler 1.7, to add  multiple
    global  source  lines.  Each  of these sources MUST be a valid Rubygems
    repository.

    Sources are checked for gems  following  the  heuristics  described  in
    SOURCE  PRIORITY.  If  a  gem  is found in more than one global source,
    Bundler will print a warning after installing the gem indicating  which
    source  was used, and listing the other sources where the gem is avail-
    able. A specific source can be selected for gems that  need  to  use  a
    non-standard repository, suppressing this warning, by using the :source
    option or a source block.

CREDENTIALS (#credentials)
    Some gem sources require a username and password. Use bundle config  to
    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 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.

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

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

RUBY (#ruby)

    If your application requires a specific Ruby version or engine, specify
    your requirements using the ruby method, with the following  arguments.
    All parameters are OPTIONAL unless otherwise specified.

VERSION (required)
    The version of Ruby that your application requires. If your application
    requires an alternate Ruby engine, such  as  JRuby  or  Rubinius,  this
    should be the Ruby version that the engine is compatible with.

        ruby "1.9.3"

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

ENGINE VERSION (:engine_version)
    Each application may specify a Ruby engine version. If an  engine  ver-
    sion  is  specified, an engine must also be specified. If the engine is
    "ruby" the engine version specified must match the Ruby version.

        ruby "1.8.7", :engine => "jruby", :engine_version => "1.6.7"

PATCHLEVEL (:patchlevel)
    Each application may specify a Ruby patchlevel.

        ruby "2.0.0", :patchlevel => "247"

GEMS (#gem)

    Specify gem requirements using the gem method, with the following argu-
    ments. All parameters are OPTIONAL unless otherwise specified.

NAME (required)
    For each gem requirement, list a single gem line.

        gem "nokogiri"

VERSION
    Each gem MAY have one or more version specifiers.

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

REQUIRE AS (:require)
    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
    file  you  want  required  has 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 "debugger", :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

GROUPS (:group or :groups)
    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 just the _default_ group
        Bundler.require(:default)        # identical
        Bundler.require(:default, :test) # requires the _default_ and _test_ groups
        Bundler.require(:test)           # requires just the _test_ group

    The Bundler CLI allows you to specify a list of groups whose gems  bun-
    dle  install  should  not install with the --without option. To specify
    multiple groups to ignore, specify a list of groups separated  by  spa-
    ces.

        bundle install --without test
        bundle install --without development test

    After running bundle install --without test, bundler will remember that
    you excluded the test group in the last installation. The next time you
    run  bundle  install, without any --without option, bundler will recall
    it.

    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 obviously 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  ver-
    sions  of  the  same  gems  in  different groups. For more details, see
    Understanding Bundler http://bundler.io/rationale.html.

PLATFORMS (:platforms)
    If a gem should only be used in a particular platform or set  of  plat-
    forms,  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) or Rubinius, but NOT Windows

    ruby_18
           ruby AND version 1.8

    ruby_19
           ruby AND version 1.9

    ruby_20
           ruby AND version 2.0

    ruby_21
           ruby AND version 2.1

    ruby_22
           ruby AND version 2.2

    mri    Same as ruby, but not Rubinius

    mri_18 mri AND version 1.8

    mri_19 mri AND version 1.9

    mri_20 mri AND version 2.0

    mri_21 mri AND version 2.1

    mri_22 mri AND version 2.2

    rbx    Same as ruby, but only Rubinius (not MRI)

    jruby  JRuby

    mswin  Windows

    mingw  Windows 32 bit 'mingw32' platform (aka RubyInstaller)

    mingw_18
           mingw AND version 1.8

    mingw_19
           mingw AND version 1.9

    mingw_20
           mingw AND version 2.0

    mingw_21
           mingw AND version 2.1

    mingw_22
           mingw AND version 2.2

    x64_mingw
           Windows 64 bit 'mingw32' platform (aka RubyInstaller x64)

    x64_mingw_20
           x64_mingw AND version 2.0

    x64_mingw_21
           x64_mingw AND version 2.1

    x64_mingw_22
           x64_mingw AND version 2.2

    As with groups, you can specify one or more platforms:

        gem "weakling",   :platforms => :jruby
        gem "ruby-debug", :platforms => :mri_18
        gem "nokogiri",   :platforms => [:mri_18, :jruby]

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

SOURCE (:source)
    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  any
    global  sources  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 global sources using  the  ordering  described  in
    SOURCE PRIORITY.

    Selecting  a  specific  source  repository this way also suppresses the
    ambiguous gem warning described above in GLOBAL SOURCES (#source).

GIT (:git)
    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  prop-
    erly 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 ver-
    sion 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"

    submodules
           Specify  :submodules => true to cause bundler to expand any sub-
           modules included in the git repository

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

        |~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.

GIT SOURCE (:git_source)
    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"

GITHUB (:github)
    NOTE: This shorthand should be avoided until Bundler 2.0, since it cur-
    rently expands to an insecure git:// URL. This allows a man-in-the-mid-
    dle attacker to compromise your system.

    If  the  git repository you want to use is hosted on GitHub and is pub-
    lic, you can use the :github shorthand to specify just the github user-
    name  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 => "git://github.com/rails/rails.git"

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

GIST (:gist)
    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 just the gist iden-
    tifier (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.

BITBUCKET (:bitbucket)
    If  the  git  repository  you want to use is hosted on Bitbucket and is
    public, you can use the :bitbucket shorthand to specify just  the  bit-
    bucket username and repository name (without the trailing ".git"), sep-
    arated 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.

PATH (:path)
    You can specify that a gem is located in a particular location  on  the
    file system. Relative paths are resolved relative to the directory con-
    taining 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 filesys-
    tem, 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

BLOCK FORM OF SOURCE, GIT, PATH, GROUP and PLATFORMS

The :source, :git, :path, :group, and :platforms options may be applied
to a group of gems by using block form.

    source "https://gems.example.com" do
      gem "some_internal_gem"
      gem "another_internal_gem"
    end

    git "https://github.com/rails/rails.git" do
      gem "activesupport"
      gem "actionpack"
    end

    platforms :ruby do
      gem "ruby-debug"
      gem "sqlite3"
    end

    group :development, :optional => true do
      gem "wirble"
      gem "faker"
    end

In  the  case of the group block form the :optional option can be given
to prevent a group from being installed unless  listed  in  the  --with
option given to the bundle install command.

In  the  case of the git block form, the :ref, :branch, :tag, and :sub-
modules options may be passed to the git method, and all  gems  in  the
block will inherit those options.

INSTALL_IF (#install_if)

The  install_if  method  allows gems to be installed based on a proc or
lambda. This is especially useful for optional gems that  can  only  be
used if certain software is installed or some other conditions are met.

    install_if -> { RUBY_PLATFORM =~ /darwin/ } do
      gem "pasteboard"
    end

GEMSPEC (#gemspec)

If you wish to use Bundler to help install dependencies for a gem while
it  is being developed, use the gemspec method to pull in the dependen-
cies listed in the .gemspec file.

The gemspec method adds any runtime dependencies as gem requirements in
the  default  group.  It  also  adds  development  dependencies  as gem
requirements in the development group. Finally, it adds a gem  require-
ment on your project (:path => '.'). In conjunction with Bundler.setup,
this allows you to require project files in your test code as you would
if  the  project  were  installed as a gem; you need not manipulate the
load path manually or require project files via relative paths.

The gemspec method supports optional :path, :glob, :name, and :develop-
ment_group options, which control where bundler looks for the .gemspec,
the glob it uses to look for the  gemspec  (defaults  to:  "{,,/*}.gem-
spec"),  what named .gemspec it uses (if more than one is present), and
which group development dependencies are included in.

SOURCE PRIORITY

When attempting to locate a gem to satisfy a gem  requirement,  bundler
uses the following priority order:

1.  The source explicitly attached to the gem (using :source, :path, or
    :git)

2.  For implicit gems (dependencies of explicit gems), any source, git,
    or  path repository declared on the parent. This results in bundler
    prioritizing the ActiveSupport gem from the  Rails  git  repository
    over ones from rubygems.org

3.  The  sources  specified  via  global  source  lines, searching each
    source in your Gemfile from last added to first added.

                            July 2015                        GEMFILE(5)