BUNDLE-INSTALL(1)														 BUNDLE-INSTALL(1)

NAME

       bundle-install - Install the dependencies specified in your Gemfile

SYNOPSIS

       bundle install [--gemfile=GEMFILE]

			[--path PATH] [--system]
			[--without=GROUP1[ GROUP2...]]
			[--local] [--deployment]
			[--binstubs[=DIRECTORY]]
			[--standalone[=GROUP1[ GROUP2...]]]
			[--quiet]

DESCRIPTION

       Install	the  gems  specified  in  your	Gemfile(5).  If this is the first time you run bundle install (and a Gemfile.lock does not exist),
       bundler will fetch all remote sources, resolve dependencies and install all needed gems.

       If a Gemfile.lock does exist, and you have not updated your Gemfile(5), bundler will fetch all remote sources,  but  use  the  dependencies
       specified in the Gemfile.lock instead of resolving dependencies.

       If a Gemfile.lock does exist, and you have updated your Gemfile(5), bundler will use the dependencies in the Gemfile.lock for all gems that
       you did not update, but will re-resolve the dependencies of gems that you did update. You can  find  more  information  about  this  update
       process below under CONSERVATIVE UPDATING.

OPTIONS

       --gemfile=<gemfile>
	      The  location  of  the  Gemfile(5) that bundler should use. This defaults to a gemfile in the current working directory. In general,
	      bundler will assume that the location of the Gemfile(5) is also the project root, and  will  look  for  the  Gemfile.lock  and  ven-
	      dor/cache relative to it.

       --path=<path>
	      The  location  to  install the gems in the bundle to. This defaults to the gem home, which is the location that gem install installs
	      gems to. This means that, by default, gems installed without a --path setting will show up in gem list. This setting is a remembered
	      option.

       --system
	      Installs the gems in the bundle to the system location. This overrides any previous remembered use of --path.

       --without=<list>
	      A space-separated list of groups to skip installing. This is a remembered option.

       --local
	      Do  not  attempt to connect to rubygems.org, instead using just the gems already present in Rubygems' cache or in vendor/cache. Note
	      that if a more appropriate platform-specific gem exists on rubygems.org, it will not be found.

       --deployment
	      Switches bundler's defaults into deployment mode. Do not use this flag on development machines.

       --binstubs[=<directory>]
	      Create a directory (defaults to bin) containing an executable that runs in the context of the bundle. For instance, if the rails gem
	      comes  with  a  rails executable, this flag will create a bin/rails executable that ensures that all dependencies used come from the
	      bundled gems.

       --shebang ruby-install-name
	      Uses the ruby executable (usually ruby) provided to execute the scripts created with --binstubs. For instance, if you use --binstubs
	      with --shebang jruby, all executables will be created to use jruby instead.

       --standalone[=<list>]
	      Make  a  bundle that can work without Ruby Gems or Bundler at runtime. It takes a space separated list of groups to install. It cre-
	      ates a bundle directory and installs the bundle there. It also generates a bundle/bundler/setup.rb file  to  replace  Bundler's  own
	      setup.

DEPLOYMENT MODE

       Bundler's  defaults  are optimized for development. To switch to defaults optimized for deployment, use the --deployment flag. Do not acti-
       vate deployment mode on development machines, as it will cause in an error when the Gemfile is modified.

       1.  A Gemfile.lock is required.

	   To ensure that the same versions of the gems you developed with and tested with  are  also  used  in  deployments,  a  Gemfile.lock	is
	   required.

	   This is mainly to ensure that you remember to check your Gemfile.lock into version control.

       2.  The Gemfile.lock must be up to date

	   In development, you can modify your Gemfile(5) and re-run bundle install to conservatively update your Gemfile.lock snapshot.

	   In deployment, your Gemfile.lock should be up-to-date with changes made in your Gemfile(5).

       3.  Gems are installed to vendor/bundle not your default system location

	   In development, it's convenient to share the gems used in your application with other applications and other scripts run on the system.

	   In  deployment,  isolation  is  a  more  important  default. In addition, the user deploying the application may not have permission to
	   install gems to the system, or the web server may not have permission to read them.

	   As a result, bundle install --deployment installs gems to the vendor/bundle directory in the application. This may be overridden  using
	   the --path option.

SUDO USAGE

       By default, bundler installs gems to the same location as gem install.

       In  some  cases, that location may not be writable by your Unix user. In that case, bundler will stage everything in a temporary directory,
       then ask you for your sudo password in order to copy the gems into their system location.

       From your perspective, this is identical to installing them gems directly into the system.

       You should never use sudo bundle install. This is because several other steps in bundle install must be performed as the current user:

       o   Updating your Gemfile.lock

       o   Updating your vendor/cache, if necessary

       o   Checking out private git repositories using your user's SSH keys

       Of these three, the first two could theoretically be performed by chowning the resulting files to $SUDO_USER. The third, however, can  only
       be  performed  by  actually  invoking  the git command as the current user. Therefore, git gems are downloaded and installed into ~/.bundle
       rather than $GEM_HOME or $BUNDLE_PATH.

       As a result, you should run bundle install as the current user, and bundler will ask for your password if it is needed to put the gems into
       their final location.

INSTALLING GROUPS

       By default, bundle install will install all gems in all groups in your Gemfile(5), except those declared for a different platform.

       However,  you  can explicitly tell bundler to skip installing certain groups with the --without option. This option takes a space-separated
       list of groups.

       While the --without option will skip installing the gems in the specified groups, it will still download those gems and use them to resolve
       the dependencies of every gem in your Gemfile(5).

       This is so that installing a different set of groups on another machine (such as a production server) will not change the gems and versions
       that you have already developed and tested against.

       Bundler offers a rock-solid guarantee that the third-party code you are running in development and testing is also the third-party code you
       are  running in production. You can choose to exclude some of that code in different environments, but you will never be caught flat-footed
       by different versions of third-party code being used in different environments.

       For a simple illustration, consider the following Gemfile(5):

	   source "http://rubygems.org"

	   gem "sinatra"

	   group :production do
	     gem "rack-perftools-profiler"
	   end

       In this case, sinatra depends on any version of Rack (>= 1.0, while rack-perftools-profiler depends on 1.x (~> 1.0).

       When you run bundle install --without production in development, we look at the dependencies of rack-perftools-profiler as well. That  way,
       you do not spend all your time developing against Rack 2.0, using new APIs unavailable in Rack 1.x, only to have bundler switch to Rack 1.2
       when the production group is used.

       This should not cause any problems in practice, because we do not attempt to install the gems in the excluded groups, and only evaluate	as
       part of the dependency resolution process.

       This  also means that you cannot include different versions of the same gem in different groups, because doing so would result in different
       sets of dependencies used in development and production. Because of the vagaries of the dependency resolution process, this usually affects
       more than just the gems you list in your Gemfile(5), and can (surprisingly) radically change the gems you are using.

REMEMBERED OPTIONS

       Some options (marked above in the OPTIONS section) are remembered between calls to bundle install, and by the Bundler runtime.

       For  instance,  if  you	run bundle install --without test, a subsequent call to bundle install that does not include a --without flag will
       remember your previous choice.

       In addition, a call to Bundler.setup will not attempt to make the gems in those groups available on the Ruby load path, as  they  were  not
       installed.

       The settings that are remembered are:

       --deployment
	      At runtime, this remembered setting will also result in Bundler raising an exception if the Gemfile.lock is out of date.

       --path Subsequent calls to bundle install will install gems to the directory originally passed to --path. The Bundler runtime will look for
	      gems in that location. You can revert this option by running bundle install --system.

       --binstubs
	      Bundler will update the executables every subsequent call to bundle install.

       --without
	      As described above, Bundler will skip the gems specified by --without in subsequent calls to bundle  install.  The  Bundler  runtime
	      will also not try to make the gems in the skipped groups available.

THE GEMFILE.LOCK
       When you run bundle install, Bundler will persist the full names and versions of all gems that you used (including dependencies of the gems
       specified in the Gemfile(5)) into a file called Gemfile.lock.

       Bundler uses this file in all subsequent calls to bundle install, which guarantees that you always use the same exact code,  even  as  your
       application moves across machines.

       Because	of  the way dependency resolution works, even a seemingly small change (for instance, an update to a point-release of a dependency
       of a gem in your Gemfile(5)) can result in radically different gems being needed to satisfy all dependencies.

       As a result, you SHOULD check your Gemfile.lock into version control. If you do not, every machine that checks out your repository (includ-
       ing  your production server) will resolve all dependencies again, which will result in different versions of third-party code being used if
       any of the gems in the Gemfile(5) or any of their dependencies have been updated.

CONSERVATIVE UPDATING

       When you make a change to the Gemfile(5) and then run bundle install, Bundler will update only the gems that you modified.

       In other words, if a gem that you did not modify worked before you called bundle install, it will continue to use the exact  same  versions
       of all dependencies as it used before the update.

       Let's take a look at an example. Here's your original Gemfile(5):

	   source "http://rubygems.org"

	   gem "actionpack", "2.3.8"
	   gem "activemerchant"

       In  this  case,	both  actionpack and activemerchant depend on activesupport. The actionpack gem depends on activesupport 2.3.8 and rack ~>
       1.1.0, while the activemerchant gem depends on activesupport >= 2.3.2, braintree >= 2.0.0, and builder >= 2.0.0.

       When the dependencies are first resolved, Bundler will select activesupport 2.3.8, which satisfies the requirements of both  gems  in  your
       Gemfile(5).

       Next, you modify your Gemfile(5) to:

	   source "http://rubygems.org"

	   gem "actionpack", "3.0.0.rc"
	   gem "activemerchant"

       The  actionpack	3.0.0.rc  gem has a number of new dependencies, and updates the activesupport dependency to = 3.0.0.rc and the rack depen-
       dency to ~> 1.2.1.

       When you run bundle install, Bundler notices that you changed the actionpack gem, but not the activemerchant gem.  It  evaluates  the  gems
       currently being used to satisfy its requirements:

       activesupport 2.3.8
	      also used to satisfy a dependency in activemerchant, which is not being updated

       rack ~> 1.1.0
	      not currently being used to satify another dependency

       Because	you  did  not explicitly ask to update activemerchant, you would not expect it to suddenly stop working after updating actionpack.
       However, satisfying the new activesupport 3.0.0.rc dependency of actionpack requires updating one of its dependencies.

       Even though activemerchant declares a very loose dependency that theoretically matches activesupport 3.0.0.rc, bundler treats gems in  your
       Gemfile(5) that have not changed as an atomic unit together with their dependencies. In this case, the activemerchant dependency is treated
       as activemerchant 1.7.1 + activesupport 2.3.8, so bundle install will report that it cannot update actionpack.

       To explicitly update actionpack, including its dependencies which other gems in the Gemfile(5) still depend on, run bundle  update  action-
       pack (see bundle update(1)).

       Summary:  In  general,  after  making a change to the Gemfile(5) , you should first try to run bundle install, which will guarantee that no
       other gems in the Gemfile(5) are impacted by the change. If that does not work, run bundle update(1) bundle-update.1.html.

								     June 2012							 BUNDLE-INSTALL(1)