PackagingDrafts/Ruby

Ruby Packaging Guidelines

Each Ruby package must indicate the Ruby ABI version it depends on with a line like

Requires: ruby(abi) = 1.9.1

Ruby packages must require ruby at build time with a BuildRequires: ruby, and may indicate the minimal ruby version they need for building.

Naming Guidelines

These naming guidelines only apply to ruby packages whose main purpose is providing a Ruby library; packages that mainly provide user-level tools that happen to be written in Ruby do not need to follow these naming guidelines, and should follow the general NamingGuidelines instead.

The name of a ruby extension/library package must be of the form ruby-UPSTREAM. If the upstream name UPSTREAM contains ruby, that should be dropped from the name. For example, the SQLite database driver for ruby is called sqlite3-ruby. The corresponding Fedora package should be called ruby-sqlite3, and not ruby-sqlite3-ruby.

A ruby extension/library package must indicate what it provides with a Provides: ruby(LIBRARY) = VERSION declaration in the spec file. The string LIBRARY should be the same as what is used in the require statement in a Ruby script that uses the library. The VERSION should be the upstream version of the library, as long as upstream follows a sane versioning scheme. For example, a Ruby script using the SQLite database driver will include it with require 'sqlite3'. The specfile for the corresponding Fedora package must contain a line Provides: ruby(sqlite3) = 1.1.0, assuming the package contains version 1.1.0 of the library.

Build Architecture and File Placement

The following only affects the files that the package installs into %{_libdir}/ruby/vendor_ruby (architecture specific) and %{_datadir}/ruby/vendor_ruby (architecture independent), i.e., Ruby library files. All other files in a Ruby package must adhere to the general Fedora Extras packaging conventions.

All non-gem ruby packages must require ruby-devel package at build time with a BuildRequires: ruby-devel.

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Macro	Expanded path	Usage
%{ruby_vendorarchdir}	/usr/lib{64}/ruby/vendor_ruby	Place for architecture specific (e.g. *.so) files.
%{ruby_vendorlibdir}	/usr/share/ruby/vendor_ruby	Place for architecture independent (e.g. *.rb) files.
%{ruby_sitearchdir}	/usr/local/lib64/ruby/vendor_ruby	Place for local architecture specific (e.g. *.so) files.
%{ruby_sitelibdir}	/usr/local/share/ruby/vendor_ruby	Place for local architecture independent (e.g. *.rb) files.

Site versus Vendor
Do not use %{ruby_sitelibdir} and %{ruby_sitearchdir} for packaging, as they are under local. Use %{ruby_vendorlibdir} and %{ruby_vendorarchdir}.

Pure Ruby packages

Pure Ruby packages must be built as noarch packages.

The Ruby library files in a pure Ruby package must be placed into %{ruby_vendorlibdir}. The specfile must use this macro.

Ruby packages with binary content/shared libraries

For packages with binary content, e.g., database drivers or any other Ruby bindings to C libraries, the package must be architecture specific.

The binary files in a Ruby package with binary content must be placed into %{ruby_vendorarchdir}. The Ruby files in such a package should be placed into %{ruby_vendorlibdir}. The specfile must use that path.

For packages which create C shared libraries using extconf.rb

export CONFIGURE_ARGS="--with-cflags='%{optflags}'"

should be used to pass CFLAGS to Makefile correctly. Also, to place the files to the correct folders during build, pass --vendor to extconf.rb like this:

extconf.rb --vendor

This applies to Ruby Gems, too.

Ruby Gems

Ruby Gems are Ruby's own packaging format. Gems contain a lot of the same metadata that RPM's need, making fairly smooth interoperation between RPM and Gems possible. This guideline ensures that Gems are packaged as RPM's in a way that ensures (1) that such RPM's fit cleanly with the rest of the distribution and (2) make it possible for the end user to satisfy dependencies of a Gem by installing the appropriate RPM-packaged Gem.

Both RPM's and Gems use similar terminology --- there are specfiles, package names, dependencies etc. for both. To keep confusion to a minimum, whenever the term from the Gem world is meant, it is explicitly called the 'Gem specification'. An unqualified 'package' in the following always means an RPM.

• Spec files must contain definition of %{gem_name}, which is the name from the Gem's specification.
• Packages that contain Ruby Gems must be called rubygem-%{gem_name}.
• The Source of the package must be the full URL to the released Gem archive; the version of the package must be the Gem's version
• The package must have a Requires on ruby(rubygems) and a BuildRequires on rubygems-devel
• The package must provide rubygem(%{gem_name}) where gem_name is the name from the Gem's specification. For every dependency on a Gem named gemdep, the package must contain a Requires on rubygem(%{gemdep}) with the same version constraints as the Gem
• The %prep section should contain the local gem install similar to this (assuming that the %{gem_name}-%{version}.gem is SOURCE0):

gem install \
	-V \
	--local \
        --install-dir .%{gem_dir} \
	--force \
	--rdoc \
	%{SOURCE0}

• The %build section of the specfile should be empty.
• The Gem must be installed into %{gem_dir}.
• If the Gem has a binary extension, it must be installed under %{gem_extdir} directory.
• The package must own the following files and directories:

%{gem_instdir}
%{gem_cache}
%{gem_spec}
%doc %{gem_docdir}

• If the Gem only contains pure Ruby code, it must be marked as BuildArch: noarch. If the Gem contains binary content (e.g., for a database driver), it must be marked as architecture specific, and all architecture specific content must be moved from the %{gem_instdir} to the %{gem_extdir} during %install

Ruby Gem with extension libraries written in C

When a Ruby Gem contains extension libraries written in C,

• First, %prep stage must contain %setup -q -c -T to create the directory where C libraries are compiled.
• Then at %build stage the Ruby Gem must be installed under the directory created at %prep stage to get C libraries compiled under there.
• When gem install is used to install Gem file, using -V option is recommend to check if CFLAGS is correctly honored.
• Finally at %install stage the whole tree under the directory created at %prep stage should be copied (not moved) to under %{buildroot}%{gemdir}.
  • When all tree under the directory created at %prep stage is moved to under %{buildroot}, find_debuginfo.sh will complain that the corresponding source files are missing.
• Installed C codes (usually under %{geminstdir}/etc) may be removed even if gem contents %{gemname} reports that installed C codes should be found there.

Note

The current guideline

If the Gem contains binary content (e.g., for a database driver), it must be marked 
as architecture specific, and all architecture specific content must be moved 
from the %{gemdir} to the [#ruby_sitearch %{ruby_sitearch} directory] during %install

must still apply.

Packaging for Gem and non-Gem use

If the same Ruby library is to be packaged for use as a Gem and as a straight Ruby library without Gem support, it must be packaged as a Gem first. To make it available to code that does not use Ruby Gems, a subpackage called ruby-%{gemname} must be created in the rubygem-%{gemname} package such that

• The subpackage must require rubygem(%gemname) = %version
• The subpackage must provide ruby(LIBRARY) = %version where LIBRARY is the same as in the [#ruby_naming general Ruby guideline] above.
• All the toplevel library files of the Gem must be symlinked into ruby_sitelib.
• The subpackage must own these symbolic links.

As an example, for activesupport, the rubygem-activesupport package would have a subpackge ruby-activesupport:

%package -n ruby-activesupport
...
Requires: rubygem(activesupport) = %version
Provides: ruby(active_support) = %version  # The underscore is intentional, not a typo
...
%files -n ruby-activesupport
%{ruby_sitelib}/active_support
%{ruby_sitelib}/active_support.rb

Tips for Packagers

Gems carry a lot of metadata; gem2rpm is a tool to generate an initial specfile and/or source RPM from a Gem. The generated specfile still needs some hand-editing, but conforms to 90% with this guideline.