ruby--ruby/man/gemfile.5.txt

GEMFILE(5)							    GEMFILE(5)



1mNAME0m
       1mGemfile 22m- A format for describing gem dependencies for Ruby programs

1mSYNOPSIS0m
       A 1mGemfile 22mdescribes the gem dependencies required to execute associated
       Ruby code.

       Place the 1mGemfile 22min the root of the directory containing  the  associ-
       ated  code.  For instance, in a Rails application, place the 1mGemfile 22min
       the same directory as the 1mRakefile22m.

1mSYNTAX0m
       A 1mGemfile 22mis evaluated as Ruby code, in a context which makes available
       a number of methods used to describe the gem requirements.

1mGLOBAL SOURCES0m
       At the top of the 1mGemfile22m, add a line for the 1mRubygems 22msource that con-
       tains the gems listed in the 1mGemfile22m.



	   source "https://rubygems.org"



       It is possible, but not recommended as of Bundler 1.7, to add  multiple
       global  1msource  22mlines.  Each  of these 1msource22ms 1mMUST 22mbe a valid Rubygems
       repository.

       Sources are checked for gems  following	the  heuristics  described  in
       4mSOURCE24m  4mPRIORITY24m.  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 1m:source0m
       option or a 1msource 22mblock.

   1mCREDENTIALS0m
       Some gem sources require a username and password. Use bundle  config(1)
       4mbundle-config.1.html24m  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 1mconfig22m.

1mRUBY0m
       If your application requires a specific Ruby version or engine, specify
       your  requirements using the 1mruby 22mmethod, with the following arguments.
       All parameters are 1mOPTIONAL 22munless otherwise specified.

   1mVERSION (required)0m
       The version of Ruby that your application requires. If your application
       requires  an  alternate	Ruby  engine, such as JRuby, Rubinius or Truf-
       fleRuby, this should be the Ruby version that the engine is  compatible
       with.



	   ruby "1.9.3"



   1mENGINE0m
       Each  application 4mmay24m specify a Ruby engine. If an engine is specified,
       an engine version 4mmust24m also be specified.

       What exactly is an Engine? - A Ruby engine is an implementation of  the
       Ruby language.

       o   For	background:  the  reference  or original implementation of the
	   Ruby  programming  language	is  called  Matz's  Ruby   Interpreter
	   4mhttps://en.wikipedia.org/wiki/Ruby_MRI24m,  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.

       o   Other implementations 4mhttps://www.ruby-lang.org/en/about/24m  of  Ruby
	   exist. Some of the more well-known implementations include Rubinius
	   4mhttps://rubinius.com/24m, and JRuby 4mhttp://jruby.org/24m. Rubinius is  an
	   alternative	implementation	of  Ruby  written in Ruby. JRuby is an
	   implementation of Ruby on the JVM, short for Java Virtual Machine.



   1mENGINE VERSION0m
       Each application 4mmay24m specify a Ruby engine version. If an  engine  ver-
       sion  is  specified, an engine 4mmust24m also be specified. If the engine is
       "ruby" the engine version specified 4mmust24m match the Ruby version.



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



   1mPATCHLEVEL0m
       Each application 4mmay24m specify a Ruby patchlevel.



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



1mGEMS0m
       Specify gem requirements using the 1mgem 22mmethod, with the following argu-
       ments. All parameters are 1mOPTIONAL 22munless otherwise specified.

   1mNAME (required)0m
       For each gem requirement, list a single 4mgem24m line.



	   gem "nokogiri"



   1mVERSION0m
       Each 4mgem24m 1mMAY 22mhave one or more version specifiers.



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



   1mREQUIRE AS0m
       Each  4mgem24m  1mMAY 22mspecify files that should be used when autorequiring via
       1mBundler.require22m. You may pass an array with multiple files or  1mtrue  22mif
       file  you  want	1mrequired  22mhas same name as 4mgem24m or 1mfalse 22mto 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



   1mGROUPS0m
       Each  4mgem24m  1mMAY  22mspecify  membership in one or more groups. Any 4mgem24m that
       does not specify membership in any  group  is  placed  in  the  1mdefault0m
       group.



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



       The  Bundler  runtime  allows  its  two main methods, 1mBundler.setup 22mand
       1mBundler.require22m, 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  1mbun-0m
       1mdle  install  22mshould  not install with the 1m--without 22moption. 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 1mbundle install --without test22m, bundler will remember that
       you excluded the test group in the last installation. The next time you
       run  1mbundle  install22m, without any 1m--without option22m, bundler will recall
       it.

       Also, calling 1mBundler.setup 22mwith  no  parameters,  or  calling  1mrequire0m
       1m"bundler/setup"  22mwill setup all groups except for the ones you excluded
       via 1m--without 22m(since they are not available).

       Note that on 1mbundle install22m, 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 4mhttp://bundler.io/rationale.html24m.

   1mPLATFORMS0m
       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  1m--without  22minstall-time
       flag to exclude groups of gems for other platforms.

       There are a number of 1mGemfile 22mplatforms:

       1mruby	22mC Ruby (MRI), Rubinius or TruffleRuby, but 1mNOT 22mWindows

       1mmri	22mSame as 4mruby24m, but only C Ruby (MRI)

       1mmingw	22mWindows 32 bit 'mingw32' platform (aka RubyInstaller)

       1mx64_mingw0m
	      Windows 64 bit 'mingw32' platform (aka RubyInstaller x64)

       1mrbx	22mRubinius

       1mjruby	22mJRuby

       1mtruffleruby0m
	      TruffleRuby

       1mmswin	22mWindows

       You  can  restrict  further  by	platform and version for all platforms
       4mexcept24m for 1mrbx22m, 1mjruby22m, 1mtruffleruby 22mand 1mmswin22m.

       To specify a version in addition to a platform, append the version num-
       ber without the delimiter to the platform. For example, to specify that
       a gem should only be used on platforms with Ruby 2.3, use:



	   ruby_23



       The full list of platforms and supported versions includes:

       1mruby	22m1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5

       1mmri	22m1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5

       1mmingw	22m1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5

       1mx64_mingw0m
	      2.0, 2.1, 2.2, 2.3, 2.4, 2.5

       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 (1mbundle install  4m22mbundle-install.1.html24m,
       1mBundler.setup22m,  1mBundler.require22m)  behave  exactly  the  same  as if any
       groups not matching the current platform were explicitly excluded.

   1mSOURCE0m
       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
       4mSOURCE24m 4mPRIORITY24m.

       Selecting a specific source repository this  way  also  suppresses  the
       ambiguous gem warning described above in 4mGLOBAL24m 4mSOURCES24m 4m(#source)24m.

       Using  the  1m:source  22moption  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.

   1mGIT0m
       If necessary, you can specify that a gem is located at a particular git
       repository using the 1m:git 22mparameter. The repository can be accessed via
       several protocols:

       1mHTTP(S)0m
	      gem "rails", :git => "https://github.com/rails/rails.git"

       1mSSH	22mgem "rails", :git => "git@github.com:rails/rails.git"

       1mgit	22mgem "rails", :git => "git://github.com/rails/rails.git"

       If using SSH, the user that you use to run 1mbundle install MUST 22mhave the
       appropriate keys available in their 1m$HOME/.ssh22m.

       1mNOTE22m: 1mhttp:// 22mand 1mgit:// 22mURLs 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  1mgroup22m,  1mplatforms22m,  and  1mrequire  22moptions are available and behave
       exactly the same as they would for a normal gem.

       A git repository 1mSHOULD 22mhave at least one file,  at  the  root  of	the
       directory  containing  the  gem, with the extension 1m.gemspec22m. This file
       1mMUST 22mcontain a valid gem specification, as expected by  the  1mgem	build0m
       command.

       If  a  git repository does not have a 1m.gemspec22m, 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 1m.gemspec 22mfor the gem  you  attached  it
       to,  a version specifier, if provided, means that the git repository is
       only valid if the 1m.gemspec 22mspecifies 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 1mnot 22mhave a 1m.gemspec 22mfor the gem you attached
       it to, a version specifier 1mMUST 22mbe provided. Bundler will use this ver-
       sion in the simple 1m.gemspec 22mit creates.

       Git repositories support a number of additional options.

       1mbranch22m, 1mtag22m, and 1mref0m
	      You  1mMUST 22monly specify at most one of these options. The default
	      is 1m:branch => "master"0m

       For example:

	      git "https://github.com/rails/rails.git", :branch  =>  "5-0-sta-
	      ble" do

	      git "https://github.com/rails/rails.git", :tag => "v5.0.0" do

	      git "https://github.com/rails/rails.git", :ref => "4aded" do

       1msubmodules0m
	      For	   reference,	       a	 git	     submodule
	      4mhttps://git-scm.com/book/en/v2/Git-Tools-Submodules24m	 lets	you
	      have  another  git repository within a subfolder of your reposi-
	      tory. Specify 1m:submodules => true 22mto cause bundler to expand any
	      submodules included in the git repository

       If  a  git repository contains multiple 1m.gemspecs22m, each 1m.gemspec 22mrepre-
       sents a gem located at the same place in the file system as  the  1m.gem-0m
       1mspec22m.



	   |~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 1mgem build name.gemspec 22mand  then
       installs the resulting gem. The 1mgem build 22mcommand, which comes standard
       with Rubygems, evaluates the 1m.gemspec 22min the context of  the  directory
       in which it is located.

   1mGIT SOURCE0m
       A  custom  git source can be defined via the 1mgit_source 22mmethod. 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"



   1mGITHUB0m
       1mNOTE22m: This shorthand should be avoided until Bundler 2.0, since it cur-
       rently expands to an insecure 1mgit:// 22mURL. 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 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 => "git://github.com/rails/rails.git"



       Since the 1mgithub 22mmethod is a specialization of 1mgit_source22m, it accepts a
       1m:branch 22mnamed argument.

   1mGIST0m
       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  1mgist 22mmethod is a specialization of 1mgit_source22m, it accepts a
       1m:branch 22mnamed argument.

   1mBITBUCKET0m
       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 1mbitbucket  22mmethod  is  a	specialization	of  1mgit_source22m,  it
       accepts a 1m:branch 22mnamed argument.

   1mPATH0m
       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 1mGemfile22m.

       Similar	to the semantics of the 1m:git 22moption, the 1m:path 22moption requires
       that the directory in question either contains a 1m.gemspec 22mfor the  gem,
       or that you specify an explicit version that bundler should use.

       Unlike  1m:git22m,  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 1mpath 22moption 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



1mBLOCK FORM OF SOURCE, GIT, PATH, GROUP and PLATFORMS0m
       The 1m:source22m, 1m:git22m, 1m:path22m, 1m:group22m, and 1m:platforms 22moptions 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	1m--with0m
       option given to the 1mbundle install 22mcommand.

       In  the	case of the 1mgit 22mblock form, the 1m:ref22m, 1m:branch22m, 1m:tag22m, and 1m:sub-0m
       1mmodules 22moptions may be passed to the 1mgit 22mmethod, and all  gems  in  the
       block will inherit those options.

       The  presence  of  a  1msource  22mblock in a Gemfile also makes that source
       available as a possible global source for any other gems which  do  not
       specify explicit sources. Thus, when defining source blocks, it is rec-
       ommended that you also ensure all other gems in the Gemfile  are  using
       explicit  sources,  either  via	source blocks or 1m:source 22mdirectives on
       individual gems.

1mINSTALL_IF0m
       The 1minstall_if 22mmethod 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



1mGEMSPEC0m
       The 1m.gemspec  4m22mhttp://guides.rubygems.org/specification-reference/24m  file
       is where you provide metadata about your gem to Rubygems. Some required
       Gemspec attributes include the name, description, and homepage of  your
       gem.  This is also where you specify the dependencies your gem needs to
       run.

       If you wish to use Bundler to help install dependencies for a gem while
       it  is being developed, use the 1mgemspec 22mmethod to pull in the dependen-
       cies listed in the 1m.gemspec 22mfile.

       The 1mgemspec 22mmethod adds any runtime dependencies as gem requirements in
       the  default  group.  It  also  adds  development  dependencies	as gem
       requirements in the 1mdevelopment 22mgroup. Finally, it adds a gem  require-
       ment on your project (1m:path => '.'22m). In conjunction with 1mBundler.setup22m,
       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 1mgemspec 22mmethod supports optional 1m:path22m, 1m:glob22m, 1m:name22m, and 1m:develop-0m
       1mment_group 22moptions, which control where bundler looks for the 1m.gemspec22m,
       the glob it uses to look for the  gemspec  (defaults  to:  "{,4m,24m/*}.gem-
       spec"),	what named 1m.gemspec 22mit uses (if more than one is present), and
       which group development dependencies are included in.

       When a 1mgemspec 22mdependency encounters version conflicts  during  resolu-
       tion,  the  local  version under development will always be selected --
       even if there are remote versions that better match other  requirements
       for the 1mgemspec 22mgem.

1mSOURCE PRIORITY0m
       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 1m:source22m, 1m:path22m, or
	   1m:git22m)

       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 1mrubygems.org0m

       3.  The sources specified  via  global  1msource  22mlines,  searching  each
	   source in your 1mGemfile 22mfrom last added to first added.






				 November 2018			    GEMFILE(5)