bundle-package - Package your needed .gem files into your application
bundle package
Copy all of the .gem files needed to run the application into the
vendor/cache directory. In the future, when running bundle install(1),
use the gems in the cache in preference to the ones on rubygems.org.
Since Bundler 1.2, the bundle package command can also package :git and
:path dependencies besides .gem files. This needs to be explicitly enabled
via the --all option. Once used, the --all option will be remembered.
When using gems that have different packages for different platforms, Bundler
1.8 and newer support caching of gems for other platforms in vendor/cache.
This needs to be enabled via the --all-platforms option. This setting will be
remembered in your local bundler configuration.
By default, if you simply run bundle install(1) after running
bundle package(1), bundler will still connect to rubygems.org
to check whether a platform-specific gem exists for any of the gems
in vendor/cache.
For instance, consider this Gemfile(5):
source "https://rubygems.org"
gem "nokogiri"
If you run bundle package under C Ruby, bundler will retrieve
the version of nokogiri for the "ruby" platform. If you deploy
to JRuby and run bundle install, bundler is forced to check to
see whether a "java" platformed nokogiri exists.
Even though the nokogiri gem for the Ruby platform is
technically acceptable on JRuby, it actually has a C extension
that does not run on JRuby. As a result, bundler will, by default,
still connect to rubygems.org to check whether it has a version
of one of your gems more specific to your platform.
This problem is also not just limited to the "java" platform.
A similar (common) problem can happen when developing on Windows
and deploying to Linux, or even when developing on OSX and
deploying to Linux.
If you know for sure that the gems packaged in vendor/cache
are appropriate for the platform you are on, you can run
bundle install --local to skip checking for more appropriate
gems, and just use the ones in vendor/cache.
One way to be sure that you have the right platformed versions
of all your gems is to run bundle package on an identical
machine and check in the gems. For instance, you can run
bundle package on an identical staging box during your
staging process, and check in the vendor/cache before
deploying to production.