Ubuntu Manpage: bundle-install - Install the dependencies specified in your Gemfile

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...]]]
                        [--trust-policy=POLICY]
                        [--no-cache]
                        [--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
vendor/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 creates a bundle directory and
installs the bundle there. It also generates a bundle/bundler/setup.rb file to
replace Bundler´s own setup.

--trust-policy=[<policy>]
Apply the Rubygems security policy named policy, where policy is one of
HighSecurity, MediumSecurity, LowSecurity, or NoSecurity. For more detail, see the
Rubygems signing documentation, linked below in SEE ALSO.

--no-cache
Do not update the cache in vendor/cache with the newly bundled gems. This does not
remove any existing cached gems, only stops the newly bundled gems from being
cached during the install.

--quiet
Do not print progress information to stdout. Instead, communicate the success of
the install operation via exit status code.

DEPLOYMENT MODE

Bundler´s defaults are optimized for development. To switch to defaults optimized for
deployment, use the --deployment flag. Do not activate 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:

       •   Updating your Gemfile.lock

       •   Updating your vendor/cache, if necessary

       •   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 "https://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 (including 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 "https://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 "https://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 dependency 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 actionpack (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.