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< PackagingDrafts

Revision as of 13:13, 9 February 2012 by Vondruch (talk | contribs) (Patching restructure, applying patches before installation added.)

This page is a draft only
It is still under construction and content may change. Do not rely on the information on this page.

Ruby ABI

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

Requires: ruby(abi) = 1.9.1


These 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 must follow applications guidelines instead.


RubyGems 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' (.gemspec). 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 rubygems-devel package carries a macros.rubygems file with following definitions:
Macro Expanded path Usage
%{gem_dir} /usr/share/gems Top directory for the Gem structure.
%{gem_instdir} %{gem_dir}/gems/%{gem_name}-%{version} Directory with the actual content of the Gem.
%{gem_libdir} %{gem_instdir}/lib The lib folder of the Gem.
%{gem_cache} %{gem_dir}/cache/%{gem_name}-%{version}.gem The cached Gem.
%{gem_spec} %{gem_dir}/specifications/%{gem_name}-%{version}.gemspec The Gem specification file.
%{gem_docdir} %{gem_dir}/doc/%{gem_name}-%{version} The rdoc documentation of the Gem.
%{gem_extdir} %{_libdir}/gems/exts/%{gem_name}-%{version} The directory for binary Gem extensions.

  • 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}). Packager must ensure that the package works properly with its specified dependencies. Please note, that Fedora may carry different versions of Gems than those specified in Gem specification, therefore the versions required in specfile may not match the dependencies in Gem specification exactly. In that case, the Gem specification (.gemspec) file must be adjusted accordingly.
  • The %prep section should contain the local gem install similar to this (assuming that the %{gem_name}-%{version}.gem is SOURCE0):
%setup -q -c -T
mkdir -p .%{gem_dir}
gem install \
	-V \
	--local \
        --install-dir .%{gem_dir} \
	--force \
	--rdoc \
  • If the Gem contains executable files, you must ad --bindir .%{_bindir} option to the gem install command.
  • The %build section of the specfile should be empty.
  • The %install section should then be used to copy the files to appropriate directory structure under %{buildroot}, for example:
mkdir -p %{buildroot}%{gem_dir}
cp -a .%{gem_dir}/* \
  • If the Gem contains executable files, you must also add:
mkdir -p %{buildroot}%{_bindir}
cp -a .%{_bindir}/* \
  • The Gem must be installed into %{gem_dir}.
  • The package must own the following files and directories:
%dir %{gem_instdir}
%doc %{gem_docdir}
  • Since the Gem is installed using RPM, you must exclude the .gem file. This file is used typically with gem pristine command to restore the Gem into its original state, but this could be achieved by equivalent RPM command. Exclude the cached Gem like this:
%exclude %{gem_cache}
  • 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.

RubyGem with extension libraries written in C

Some Ruby Gems may contain extension libraries written in C. These Gems carry an extensions section in their Gem specification file. Their specfiles have to be slightly adjusted to reflect the presence of binary files.

  • The %prep section is the same as for pure Ruby Gem, but it must add CONFIGURE_ARGS before the gem install command:
%setup -q -c -T
mkdir -p .%{gem_dir}
export CONFIGURE_ARGS="--with-cflags='%{optflags}'"
gem install \
	-V \
	--local \
        --install-dir .%{gem_dir} \
	--force \
	--rdoc \
  • The -V option should be used with gem install to check if CFLAGS is correctly honored.
  • During the %install section all architecture specific content must be moved from the %{gem_instdir} to the %{gem_extdir}. Usage of %{gem_extdir} assures that the binary files are placed under the proper directory under /usr according to FHS.
mkdir -p %{buildroot}%{gem_dir}
mkdir -p %{buildroot}%{gem_extdir}/foo
cp -a .%{gem_dir}/* %{buildroot}%{gem_dir}/

mv %{buildroot}%{gem_instdir}/foo/ %{buildroot}%{gem_extdir}/foo/
Library placement
Please note the foo subdirectory of %{buildroot}%{gem_extdir}. The foo must be replaced by first path defined by require_paths in Gem specification. Typically, it is replaced either by lib or ext.
  • The Gem package with C extension must own the %{gem_extdir} directory.
  • Installed C codes (usually under %{gem_instdir}/ext) may be removed even if gem contents %{gem_name} reports that installed C codes should be found there.

Packaging for Gem and non-Gem use

Stop (medium size).png
Packaging for non-Gem use is no longer needed
Originally, rubygem modules were not placed in ruby's library path, so we packaged rubygems for use with both gems and non-gems. The current rubygem module adds all gems to the ruby library path when it is require'd. So, packagers must not create non-Gem subpackages of rubygems for new packages. Since the majority of Ruby packages in Fedora are now packaged as installed gems, you may need to use require('rubygem') as early in the program as possible to ensure that these ruby components are properly found.

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-%{gem_name} must be created in the rubygem-%{gem_name} package such that

  • The subpackage must require rubygem(%gem_name) = %version
  • The subpackage must provide ruby(LIBRARY) = %{version} where LIBRARY is the same as in the general Ruby guideline above.
  • All the toplevel library files of the Gem must be symlinked into %{ruby_vendorlibdir}.
  • 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

Applying Patches

There are several cases, when you need to apply patch to your gem. The following paragraphs tries to demonstrate how to solve the most basic scenarios.

Ruby Code

If you are applying a patch to the Ruby code (which is platform independent), the only thing you need to do is just to apply it in the %prep section after the gem install command, for example:

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

pushd .%{gem_instdir}
%patch0 -p1

Binary Extensions

Sometimes, although you are able to successfully install the gem, you will later encounter some bug in its binary extension which needs patching. In this case, you first need to use the %patch macro as in the previous example and then you must recompile the extension in %build section. For example:

export CONFIGURE_ARGS="--with-cflags='%{optflags}'"
gem install \
	-V \
	--local \
        --install-dir .%{gem_dir} \
	--force \
	--rdoc \

pushd .%{gem_instdir}
%patch0 -p1

pushd .%{gem_instdir}/ext
make %{?_smp_mflags}

Binary Extension Fails to Build

Consider alternative package
If you find out that you need this approach, then probably the gem you are about to package is old and unmaintained. Please consider if there is not some more viable alternative.

If you are packaging a gem with binary extension, which is not ABI/API compatible with Ruby, the gem installation probably fails during compilation of the extension. In this case, you need to apply patch to fix this issue prior the installation. Unfortunately, there is no easy straight forward way how to achieve it ATM. Nevertheless, you can repack the gem with applied patch in %prep section and later install as always. For example:

%setup -q -c -T
pushd ..
gem unpack %{SOURCE0}

pushd %{gem_name}-%{version}
gem spec %{SOURCE0} -l --ruby > %{gem_name}.gemspec

%patch0 -p1

gem build %{gem_name}.gemspec

mkdir -p ./%{gem_dir}
export CONFIGURE_ARGS="--with-cflags='%{optflags}'"
gem install --local --install-dir ./%{gem_dir} \
	--force	../%{gem_name}-%{version}/%{gem_name}-%{version}.gem
Might help you
Please note that the unpacked gem might already contain:
  • Gem specification (.gemspec). If you like to use it, you must make sure that it is up-to-date.
  • Some upstream authors might have pre-prepared rake task, which can package the gem for you, instead of gem build command.
However, for consistency, you should to stay with the approach demonstrated by example above.

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.

Non-Gem Packages

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

Naming Guidelines

Note.png These naming guidelines only apply to non-Gem 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.

A list of the macros included in ruby-devel (file /etc/rpm/macros.ruby) package follows:

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/lib{64}/ruby/site_ruby Place for local architecture specific (e.g. *.so) files.
%{ruby_sitelibdir} /usr/local/share/ruby/site_ruby Place for local architecture independent (e.g. *.rb) files.

Site versus Vendor
Previously, %{ruby_sitelibdir} and %{ruby_sitearchdir} were used. However, as they are meant only for local installations, please use %{ruby_vendorlibdir} and %{ruby_vendorarchdir} instead.

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} (or its proper subdirectory). 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} (or its proper subdirectory). The Ruby files in such a package should be placed into %{ruby_vendorlibdir}. The specfile must use these macros.

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 into the correct folders during build, pass --vendor to extconf.rb like this:

extconf.rb --vendor

The CONFIGURE_ARGS definition applies to Ruby Gems, too.


By applications we mean:

  • programmes that provide user-level tools or
  • web applications, typically built using Rails, Sinatra or similar frameworks.

Their RPM packages should obey FHS rules, it means that they should be installed into %{_datadir}. Following macro can help you:

%global app_root %{_datadir}/%{name}

These packages typically have no "Provides" section, since no other libraries or applications depend on them.

A good example is the initial specfile of deltacloud-core package (shortened here):

%global app_root %{_datadir}/%{name}

Summary: Deltacloud REST API
Name: deltacloud-core
Version: 0.3.0
Release: 3%{?dist}
Group: Development/Languages
License: ASL 2.0 and MIT
Requires: rubygem(haml)
Requires(post):   chkconfig
BuildRequires: rubygem(haml)
BuildArch: noarch

The Deltacloud API is built as a service-based REST API.
You do not directly link a Deltacloud library into your program to use it.
Instead, a client speaks the Deltacloud API over HTTP to a server
which implements the REST interface.

%package doc
Summary: Documentation for %{name}
Group: Documentation
Requires:%{name} = %{version}-%{release}

%description doc
Documentation for %{name}

%setup -q -c -T 
gem unpack -V --target=%{_builddir} %{SOURCE0}


mkdir -p %{buildroot}%{app_root}
mkdir -p %{buildroot}%{_initddir}
mkdir -p %{buildroot}%{_bindir}
cp -r %{_builddir}/%{name}-%{version}/* %{buildroot}%{app_root}
mv %{buildroot}%{app_root}/support/fedora/%{name} %{buildroot}%{_initddir}
find %{buildroot}%{app_root}/lib -type f | xargs chmod -x
chmod 0755 %{buildroot}%{_initddir}/%{name}
chmod 0755 %{buildroot}%{app_root}/bin/deltacloudd
rm -rf %{buildroot}%{app_root}/support
rdoc --op %{buildroot}%{_defaultdocdir}/%{name}

# This adds the proper /etc/rc*.d links for the script
/sbin/chkconfig --add %{name}

%dir %{app_root}/

%files doc


Note, that although the source is a RubyGem, gem unpack is used instead of common gem install to extract the application and library files. These are then placed under %{_datadir}/%{name}, %{_bindir}, etc. to follow FHS and general packaging guidelines. If additional Fedora specific files (systemd .service files, configurations) are required, they should be

  • added via another %SOURCE tags
Source1: deltacloudd-fedora
  • placed into appropriate locations during %install stage
install -m 0755 %{SOURCE1} %{buildroot}%{_bindir}/deltacloudd

Running test suite

If there is test suite available for the package (even separately, for example not included in the Gem, but available in the upstream repository), you should run it. The test suite is the only tool which could assure basic functionality of package. This is helpful when mass rebuild is required for example. You could skip test suite execution only in case when not all build dependencies are met, but this must be documented in specfile. Nevertheless, the build dependencies should be imported into Fedora as soon as possible.

The tests should not be run using Rake - Rake almost always draws in some unnecessary dependencies like hoe or gemcutter.

Testing frameworks usage

Ruby community provides and supports various testing frameworks. Following paragraphs demonstrates how the test suite can be executed. Please note that the list is not exhaustive.


MiniTest is default testing framework shipped together with Ruby, however unbundled in Fedora (you must use BuildRequires: rubygem(minitest)). To run the tests using MiniTest, you can usually use something like

testrb -Ilib test


To run the tests using Test::Unit (you must use BuildRequires: rubygem(test-unit)), you can usually use something like

testrb2 -Ilib test

Note.png Please note that test suite which runs using Test::UNIT can be typically executed also by MiniTest. In that case, please prefer MiniTest.


To run the tests using RSpec >= 2 (you must use BuildRequires: rubygem(rspec-core)), you can usually use something like

rspec -Ilib spec

Test suite not included in package

Typical way of getting the tests separately from upstream follows - lets suppose you're packaging rubygem-delorean, version 1.2.0, which is hosted on Git. Tests are not included in the Gem itself, so you need to get them and adjust the specfile accordingly:

# git clone && cd delorean
# git checkout v1.2.0
# tar -czf rubygem-delorean-1.2.0-specs.tgz spec/
Source1: %{name}-%{version}-specs.tgz

# ...

pushd .%{gem_instdir}
tar xzf %{SOURCE1}

# ...

  • Make sure to include the version of the tests in the source name, so that when updating to new version, rpmbuild will fail because it won't find the proper %SOURCE1 (and this will remind you to update the tests, too).
  • Add the commands you used to get the tests into the specfile as comments. This will make it a lot easier the next time you will need to get them.
  • Run the tests as you normally would.