BUNDLE-INSTALL(1)

NAME
bundle-install - Install the dependencies specified in your Gemfile

SYNOPSIS
bundle install [--force] [--full-index] [--gemfile=GEMFILE] [--jobs=NUMBER] [--local] [--lockfile=LOCKFILE] [--no-cache] [--no-lock] [--prefer-local] [--quiet] [--retry=NUMBER] [--standalone[=GROUP[ GROUP...]]] [--trust-policy=TRUST-POLICY] [--target-rbconfig=TARGET-RBCONFIG]

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

--force, --redownload
    Force reinstalling every gem, even if already installed.

--full-index
    Bundler will not call Rubygems' API endpoint (default) but download and cache a (currently big) index file of all gems. Performance can be improved for large bundles that seldom change by enabling this option.

--gemfile=GEMFILE
    The location of the Gemfile(5) which Bundler should use. This defaults to a Gemfile(5) in the current working directory. In general, Bundler will assume that the location of the Gemfile(5) is also the project's root and will try to find Gemfile.lock and vendor/cache relative to this location.

--jobs=<number>, -j=<number>
    The maximum number of parallel download and install jobs. The default is the number of available processors.

--local
    Do not attempt to connect to rubygems.org. Instead, Bundler will use the gems already present in Rubygems' cache or in vendor/cache. Note that if an appropriate platform-specific gem exists on rubygems.org it will not be found.

--lockfile=LOCKFILE
    The location of the lockfile which Bundler should use. This defaults to the Gemfile location with .lock appended.

--prefer-local
    Force using locally installed gems, or gems already present in Rubygems' cache or in vendor/cache, when resolving, even if newer versions are available remotely. Only attempt to connect to rubygems.org for gems that are not present locally.

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

--no-lock
    Do not create a lockfile. Useful if you want to install dependencies but not lock versions of gems. Recommended for library development, and other situations where the code is expected to work with a range of dependency versions.

    This has the same effect as using lockfile false in the Gemfile. See gemfile(5) for more information.

--quiet
    Do not print progress information to the standard output.

--retry=[<number>]
    Retry failed network or git requests for number times.

--standalone[=<list>]
    Makes a bundle that can work without depending on Rubygems or Bundler at runtime. A space separated list of groups to install can be specified. Bundler creates a directory named bundle and installs the bundle there. It also generates a bundle/bundler/setup.rb file to replace Bundler's own setup in the manner required.

--trust-policy=TRUST-POLICY
    Apply the Rubygems security policy policy, where policy is one of HighSecurity, MediumSecurity, LowSecurity, AlmostNoSecurity, or NoSecurity. For more details, please see the Rubygems signing documentation linked below in SEE ALSO.

--target-rbconfig=TARGET-RBCONFIG
    Path to rbconfig.rb for the deployment target platform.

DEPLOYMENT MODE
Bundler's defaults are optimized for development. To switch to defaults optimized for deployment and for CI, use the deployment setting. Do not activate deployment mode on development machines, as it will cause an error when the Gemfile(5) 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 that 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, when deployment is configured, bundle install installs gems to the vendor/bundle directory in the application. This may be overridden using the path setting.

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 setting. This setting takes a space-separated list of groups.

While the without setting will skip installing the gems in the specified groups, bundle install 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 configure bundle config 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 the gems you list in your Gemfile(5), and can (surprisingly) radically change the gems you are using.

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, in both applications and gems. 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.

When Bundler first shipped, the Gemfile.lock was included in the .gitignore file included with generated gems. Over time, however, it became clear that this practice forces the pain of broken dependencies onto new contributors, while leaving existing contributors potentially unaware of the problem. Since bundle install is usually the first step towards a contribution, the pain of broken dependencies would discourage new contributors from contributing. As a result, we have revised our guidance for gem authors to now recommend checking in the lock for gems.

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 satisfy 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 gem in the Gemfile(5) is impacted by the change. If that does not work, run bundle update(1) bundle-update.1.html.

SEE ALSO

•   Gem install docs https://guides.rubygems.org/rubygems-basics/#installing-gems

•   Rubygems signing docs https://guides.rubygems.org/security/