Website rubygems.org | Operating system | |
Stable release 2.6.6 / June 22, 2016; 8 months ago (2016-06-22) | ||
RubyGems is a package manager for the Ruby programming language that provides a standard format for distributing Ruby programs and libraries (in a self-contained format called a "gem"), a tool designed to easily manage the installation of gems, and a server for distributing them.
Contents
- History
- Structure of a gem
- Working with Gems
- gem command
- gem usage
- gem package building
- Security Concerns
- References
The interface for RubyGems is a command-line tool called gem which can install libraries and manage RubyGems. RubyGems integrates with Ruby run-time loader to help find and load installed gems from standardized library folders.Though it is possible to use a private RubyGems repository, the public repository is most commonly used for gem management. There are about 123,000 gems in the public repository with over 9.8 billion downloads.
The public repository helps users find gems, resolve dependencies and install them. RubyGems is bundled with the standard Ruby package as of Ruby 1.9.
History
Development on RubyGems started in November 2003 and was released to the public on March 14, 2004, or Pi Day 2004. In 2010, the default public repository for gems moved from http://gems.rubyforge.org to http://rubygems.org, which is still in use. Also, RubyGems development was moved to GitHub in 2010. Though RubyGems has existed since Ruby 1.8, it was not a part of the standard Ruby distribution until Ruby 1.9.
Previously, compatibility with RubyGems and Ruby varied. Many versions of RubyGems are almost fully incompatible with many versions of Ruby and some versions had key features unusable. For example, Ruby 1.9 came with RubyGems 1.3.7 in its standard distribution, but RubyGems 1.4.x was not compatible with Ruby 1.9. This meant that updating RubyGems on Ruby 1.9 was not possible until RubyGems 1.5.0 was released in 2011, two years after the first stable release of Ruby 1.9. These compatibility issues led to a rapid development of RubyGems, switching to a 4-6 week release schedule. This is reflected in there being 38 releases from 2004-2010 and 117 releases from 2011-2016. 45 versions were released in 2013, which is the highest number of releases in a year for RubyGems.
Structure of a gem
Every gem contains a name, version and platform. Gems work only on ruby designed for a particular platform based on CPU architecture and operating system type and version.
Each gem consists of:
- Code
- Documentation
- Gem specification (Gemspec)
The code organization follows the following structure for a gem called gem_name:
gem_name/
├── bin/
│ └── gem_name
├── lib/
│ └── gem_name.rb
├── test/
│ └── test_gem_name.rb
├── README
├── Rakefile
└── gem_name.gemspec
Working with Gems
Gems are packages similar to Ebuilds. They contain package information along with files to install.
Gems are usually built from ".gemspec" files, which are YAML files containing information on Gems. However, Ruby code may also build Gems directly. Such a practice is usually used with Rake.
gem command
The gem command is used to build, upload, download, and install Gem packages.
gem usage
RubyGems is very similar to apt-get, portage, yum and npm in functionality.
Installation:
gem install mygemUninstallation:
gem uninstall mygemListing installed gems:
gem listListing available gems, e.g.:
gem list —rCreate RDoc documentation for all gems:
gem rdoc—allAdding a trusted certificate:
gem cert -aDownload but do not install a gem:
gem fetch mygemSearch available gems, e.g.:
gem search STRING—remotegem package building
The gem command may also be used to build and maintain .gemspec and .gem files.
Build .gem from a .gemspec file:
Security Concerns
Since ruby gems run their own code in an application it may lead to various security issues due to installation of malicious gems. The creator of malicious gems may be able to compromise the user system or server.
A number of methods have been developed to counter the security threat: