bundle install

bundle-install - Install the dependencies specified in your Gemfile

bundle install [--gemfile=GEMFILE]
                 [--path PATH] [--system]
                 [--without=GROUP1[ GROUP2...]]
                 [--local] [--deployment]
                 [--binstubs[=DIRECTORY]]
                 [--standalone[=GROUP1[ GROUP2...]]]
                 [--quiet]
                 [--no-cache]

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.

--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.

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 "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 (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 "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 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).