class Gem::Installer

The installer installs the files contained in the .gem into the Gem.home.

Gem::Installer does the work of putting files in all the right places on the filesystem including unpacking the gem into its gem dir, installing the gemspec in the specifications dir, storing the cached gem in the cache dir, and installing either wrappers or symlinks for executables.

The installer invokes pre and post install hooks. Hooks can be added either through a rubygems_plugin.rb file in an installed gem or via a rubygems/defaults/#{RUBY_ENGINE}.rb or rubygems/defaults/operating_system.rb file. See Gem.pre_install and Gem.post_install for details.

Constants

ENV_PATHS: Paths where env(1) might live. Some systems are broken and have it in /bin

Attributes

exec_format[W]

Overrides the executable format.

This is a sprintf format with a “%s” which will be replaced with the executable name. It is based off the ruby executable name's difference from “ruby”.

install_lock[R]

Certain aspects of the install process are not thread-safe. This lock is used to allow multiple threads to install Gems at the same time.

path_warning[RW]

True if we've warned about PATH not including Gem.bindir

bin_dir[RW]

The directory a gem's executables will be installed into

build_args[W]

Available through requiring rubygems/installer_test_case

env_shebang[W]

Available through requiring rubygems/installer_test_case

force[W]

Available through requiring rubygems/installer_test_case

format[W]

Available through requiring rubygems/installer_test_case

format_executable[W]

Available through requiring rubygems/installer_test_case

gem[R]

Filename of the gem being installed.

gem_dir[W]

Available through requiring rubygems/installer_test_case

gem_home[RW]

The gem repository the gem will be installed into

ignore_dependencies[W]

Available through requiring rubygems/installer_test_case

options[R]

The options passed when the Gem::Installer was instantiated.

security_policy[W]

Available through requiring rubygems/installer_test_case

wrappers[W]

Available through requiring rubygems/installer_test_case

Public Class Methods

at(path, options = {}) click to toggle source

Construct an installer object for the gem file located at path

# File lib/rubygems/installer.rb, line 100
def self.at path, options = {}
  security_policy = options[:security_policy]
  package = Gem::Package.new path, security_policy
  new package, options
end

exec_format() click to toggle source

Defaults to use Ruby's program prefix and suffix.

# File lib/rubygems/installer.rb, line 91
def exec_format
  @exec_format ||= Gem.default_exec_format
end

for_spec(spec, options = {}) click to toggle source

Construct an installer object for an ephemeral gem (one where we don't actually have a .gem file, just a spec)

# File lib/rubygems/installer.rb, line 132
def self.for_spec spec, options = {}
  # FIXME: we should have a real Package class for this
  new FakePackage.new(spec), options
end

new(package, options={}) click to toggle source

Constructs an Installer instance that will install the gem located at gem. options is a Hash with the following keys:

:bin_dir: Where to put a bin wrapper if needed.
:development: Whether or not development dependencies should be installed.
:env_shebang: Use /usr/bin/env in bin wrappers.
:force: Overrides all version checks and security policy checks, except for a signed-gems-only policy.
:format_executable: Format the executable the same as the Ruby executable. If your Ruby is ruby18, foo_exec will be installed as foo_exec18.
:ignore_dependencies: Don't raise if a dependency is missing.
:install_dir: The directory to install the gem into.
:security_policy: Use the specified security policy. See Gem::Security
:user_install: Indicate that the gem should be unpacked into the users personal gem directory.
:only_install_dir: Only validate dependencies against what is in the install_dir
:wrappers: Install wrappers if true, symlinks if false.
:build_args: An Array of arguments to pass to the extension builder process. If not set, then Gem::Command.build_args is used

# File lib/rubygems/installer.rb, line 160
def initialize(package, options={})
  require 'fileutils'

  @options = options
  if package.is_a? String
    security_policy = options[:security_policy]
    @package = Gem::Package.new package, security_policy
    if $VERBOSE
      warn "constructing an Installer object with a string is deprecated. Please use Gem::Installer.at (called from: #{caller.first})"
    end
  else
    @package = package
  end

  process_options

  if options[:user_install] and not options[:unpack] then
    @gem_home = Gem.user_dir
    @bin_dir = Gem.bindir gem_home unless options[:bin_dir]
    check_that_user_bin_dir_is_in_path
  end
end

Public Instance Methods

app_script_text(bin_file_name) click to toggle source

Return the text for an application file.

# File lib/rubygems/installer.rb, line 691
  def app_script_text(bin_file_name)
    return <<-TEXT
#{shebang bin_file_name}
#
# This file was generated by RubyGems.
#
# The application '#{spec.name}' is installed as part of a gem, and
# this file is here to facilitate running it.
#

require 'rubygems'

version = "#{Gem::Requirement.default}.a"

if ARGV.first
  str = ARGV.first
  str = str.dup.force_encoding("BINARY") if str.respond_to? :force_encoding
  if str =~ /\\A_(.*)_\\z/ and Gem::Version.correct?($1) then
    version = $1
    ARGV.shift
  end
end

gem '#{spec.name}', version
load Gem.bin_path('#{spec.name}', '#{bin_file_name}', version)
TEXT
  end

build_extensions() click to toggle source

Builds extensions. Valid types of extensions are extconf.rb files, configure scripts and rakefiles or mkrf_conf files.

# File lib/rubygems/installer.rb, line 738
def build_extensions
  builder = Gem::Ext::Builder.new spec, @build_args

  builder.build_extensions
end

default_spec_file() click to toggle source

The location of the default spec file for default gems.

# File lib/rubygems/installer.rb, line 405
def default_spec_file
  File.join Gem::Specification.default_specifications_dir, "#{spec.full_name}.gemspec"
end

dir() click to toggle source

Return the target directory where the gem is to be installed. This directory is not guaranteed to be populated.

# File lib/rubygems/installer.rb, line 790
def dir
  gem_dir.to_s
end

ensure_dependency(spec, dependency) click to toggle source

Ensure that the dependency is satisfied by the current installation of gem. If it is not an exception is raised.

spec: Gem::Specification
dependency: Gem::Dependency

# File lib/rubygems/installer.rb, line 368
def ensure_dependency(spec, dependency)
  unless installation_satisfies_dependency? dependency then
    raise Gem::InstallError, "#{spec.name} requires #{dependency}"
  end
  true
end

ensure_loadable_spec() click to toggle source

Ensures the Gem::Specification written out for this gem is loadable upon installation.

# File lib/rubygems/installer.rb, line 585
def ensure_loadable_spec
  ruby = spec.to_ruby_for_cache
  ruby.untaint

  begin
    eval ruby
  rescue StandardError, SyntaxError => e
    raise Gem::InstallError,
          "The specification for #{spec.full_name} is corrupt (#{e.class})"
  end
end

extract_bin() click to toggle source

Extracts only the bin/ files from the gem into the gem directory. This is used by default gems to allow a gem-aware stub to function without the full gem installed.

# File lib/rubygems/installer.rb, line 769
def extract_bin
  @package.extract_files gem_dir, "bin/*"
end

extract_files() click to toggle source

Reads the file index and extracts each file into the gem directory.

Ensures that files can't be installed outside the gem directory.

# File lib/rubygems/installer.rb, line 760
def extract_files
  @package.extract_files gem_dir
end

formatted_program_filename(filename) click to toggle source

Prefix and suffix the program filename the same as ruby.

# File lib/rubygems/installer.rb, line 776
def formatted_program_filename(filename)
  if @format_executable then
    self.class.exec_format % File.basename(filename)
  else
    filename
  end
end

gem_dir() click to toggle source

Lazy accessor for the spec's gem directory.

# File lib/rubygems/installer.rb, line 246
def gem_dir
  @gem_dir ||= File.join(gem_home, "gems", spec.full_name)
end

generate_bin_script(filename, bindir) click to toggle source

Creates the scripts to run the applications in the gem.

# File lib/rubygems/installer.rb, line 485
def generate_bin_script(filename, bindir)
  bin_script_path = File.join bindir, formatted_program_filename(filename)

  FileUtils.rm_f bin_script_path # prior install may have been --no-wrappers

  File.open bin_script_path, 'wb', 0755 do |file|
    file.print app_script_text(filename)
  end

  verbose bin_script_path

  generate_windows_script filename, bindir
end

generate_bin_symlink(filename, bindir) click to toggle source

Creates the symlinks to run the applications in the gem. Moves the symlink if the gem being installed has a newer version.

# File lib/rubygems/installer.rb, line 503
def generate_bin_symlink(filename, bindir)
  if Gem.win_platform? then
    alert_warning "Unable to use symlinks on Windows, installing wrapper"
    generate_bin_script filename, bindir
    return
  end

  src = File.join gem_dir, spec.bindir, filename
  dst = File.join bindir, formatted_program_filename(filename)

  if File.exist? dst then
    if File.symlink? dst then
      link = File.readlink(dst).split File::SEPARATOR
      cur_version = Gem::Version.create(link[-3].sub(/^.*-/, ''))
      return if spec.version < cur_version
    end
    File.unlink dst
  end

  FileUtils.symlink src, dst, :verbose => Gem.configuration.really_verbose
end

generate_windows_script(filename, bindir) click to toggle source

Creates windows .bat files for easy running of commands

# File lib/rubygems/installer.rb, line 436
def generate_windows_script(filename, bindir)
  if Gem.win_platform? then
    script_name = filename + ".bat"
    script_path = File.join bindir, File.basename(script_name)
    File.open script_path, 'w' do |file|
      file.puts windows_stub_script(bindir, filename)
    end

    verbose script_path
  end
end

install() click to toggle source

Installs the gem and returns a loaded Gem::Specification for the installed gem.

The gem will be installed with the following structure:

@gem_home/
  cache/<gem-version>.gem #=> a cached copy of the installed gem
  gems/<gem-version>/... #=> extracted files
  specifications/<gem-version>.gemspec #=> the Gem::Specification

# File lib/rubygems/installer.rb, line 270
def install
  pre_install_checks

  FileUtils.rm_f File.join gem_home, 'specifications', spec.spec_name

  run_pre_install_hooks

  # Completely remove any previous gem files
  FileUtils.rm_rf gem_dir

  FileUtils.mkdir_p gem_dir

  if @options[:install_as_default]
    spec.loaded_from = default_spec_file
    extract_bin
    write_default_spec
  else
    spec.loaded_from = spec_file
    extract_files

    build_extensions
    write_build_info_file
    run_post_build_hooks

    generate_bin
    write_spec
    write_cache_file
  end

  say spec.post_install_message unless spec.post_install_message.nil?

  Gem::Installer.install_lock.synchronize { Gem::Specification.reset }

  run_post_install_hooks

  spec

# TODO This rescue is in the wrong place. What is raising this exception?
# move this rescue to around the code that actually might raise it.
rescue Zlib::GzipFile::Error
  raise Gem::InstallError, "gzip error installing #{gem}"
end

installation_satisfies_dependency?(dependency) click to toggle source

True if the gems in the system satisfy dependency.

# File lib/rubygems/installer.rb, line 378
def installation_satisfies_dependency?(dependency)
  return true if @options[:development] and dependency.type == :development
  return true if installed_specs.detect { |s| dependency.matches_spec? s }
  return false if @only_install_dir
  not dependency.matching_specs.empty?
end

installed_specs() click to toggle source

Return an Array of Specifications contained within the #gem_home we'll be installing into.

# File lib/rubygems/installer.rb, line 348
def installed_specs
  @specs ||= begin
    specs = []

    Dir[File.join(gem_home, "specifications", "*.gemspec")].each do |path|
      spec = Gem::Specification.load path.untaint
      specs << spec if spec
    end

    specs
  end
end

pre_install_checks() click to toggle source

Performs various checks before installing the gem such as the install repository is writable and its directories exist, required Ruby and rubygems versions are met and that dependencies are installed.

Version and dependency checks are skipped if this install is forced.

The dependent check will be skipped this install is ignoring dependencies.

# File lib/rubygems/installer.rb, line 803
def pre_install_checks
  verify_gem_home options[:unpack]

  ensure_loadable_spec

  if options[:install_as_default]
    Gem.ensure_default_gem_subdirectories gem_home
  else
    Gem.ensure_gem_subdirectories gem_home
  end

  return true if @force

  ensure_required_ruby_version_met
  ensure_required_rubygems_version_met
  ensure_dependencies_met unless @ignore_dependencies

  true
end

shebang(bin_file_name) click to toggle source

Generates a #! line for bin_file_name's wrapper copying arguments if necessary.

If the :custom_shebang config is set, then it is used as a template for how to create the shebang used for to run a gem's executables.

The template supports 4 expansions:

$env    the path to the unix env utility
$ruby   the path to the currently running ruby interpreter
$exec   the path to the gem's executable
$name   the name of the gem the executable is for

# File lib/rubygems/installer.rb, line 540
def shebang(bin_file_name)
  ruby_name = RbConfig::CONFIG['ruby_install_name'] if @env_shebang
  path = File.join gem_dir, spec.bindir, bin_file_name
  first_line = File.open(path, "rb") {|file| file.gets}

  if /\A#!/ =~ first_line then
    # Preserve extra words on shebang line, like "-w".  Thanks RPA.
    shebang = first_line.sub(/\A\#!.*?ruby\S*((\s+\S+)+)/, "#!#{Gem.ruby}")
    opts = $1
    shebang.strip! # Avoid nasty ^M issues.
  end

  if which = Gem.configuration[:custom_shebang]
    # replace bin_file_name with "ruby" to avoid endless loops
    which = which.gsub(/ #{bin_file_name}$/," #{RbConfig::CONFIG['ruby_install_name']}")

    which = which.gsub(/\$(\w+)/) do
      case $1
      when "env"
        @env_path ||= ENV_PATHS.find {|env_path| File.executable? env_path }
      when "ruby"
        "#{Gem.ruby}#{opts}"
      when "exec"
        bin_file_name
      when "name"
        spec.name
      end
    end

    "#!#{which}"
  elsif not ruby_name then
    "#!#{Gem.ruby}#{opts}"
  elsif opts then
    "#!/bin/sh\n'exec' #{ruby_name.dump} '-x' \"$0\" \"$@\"\n#{shebang}"
  else
    # Create a plain shebang line.
    @env_path ||= ENV_PATHS.find {|env_path| File.executable? env_path }
    "#!#{@env_path} #{ruby_name}"
  end
end

spec() click to toggle source

Lazy accessor for the installer's spec.

# File lib/rubygems/installer.rb, line 253
def spec
  @package.spec
rescue Gem::Package::Error => e
  raise Gem::InstallError, "invalid gem: #{e.message}"
end

spec_file() click to toggle source

The location of the spec file that is installed.

# File lib/rubygems/installer.rb, line 397
def spec_file
  File.join gem_home, "specifications", "#{spec.full_name}.gemspec"
end

unpack(directory) click to toggle source

Unpacks the gem into the given directory.

# File lib/rubygems/installer.rb, line 388
def unpack(directory)
  @gem_dir = directory
  extract_files
end

windows_stub_script(bindir, bin_file_name) click to toggle source

return the stub script text used to launch the true Ruby script

# File lib/rubygems/installer.rb, line 722
  def windows_stub_script(bindir, bin_file_name)
    ruby = Gem.ruby.gsub(/^\"|\"$/, "").tr(File::SEPARATOR, "\\")
    return <<-TEXT
@ECHO OFF
IF NOT "%~f0" == "~f0" GOTO :WinNT
@"#{ruby}" "#{File.join(bindir, bin_file_name)}" %1 %2 %3 %4 %5 %6 %7 %8 %9
GOTO :EOF
:WinNT
@"#{ruby}" "%~dpn0" %*
TEXT
  end

write_build_info_file() click to toggle source

Writes the file containing the arguments for building this gem's extensions.

# File lib/rubygems/installer.rb, line 827
def write_build_info_file
  return if @build_args.empty?

  build_info_dir = File.join gem_home, 'build_info'

  FileUtils.mkdir_p build_info_dir

  build_info_file = File.join build_info_dir, "#{spec.full_name}.info"

  open build_info_file, 'w' do |io|
    @build_args.each do |arg|
      io.puts arg
    end
  end
end

write_cache_file() click to toggle source

Writes the .gem file to the cache directory

# File lib/rubygems/installer.rb, line 846
def write_cache_file
  cache_file = File.join gem_home, 'cache', spec.file_name
  @package.copy_to cache_file
end

write_default_spec() click to toggle source

Writes the full .gemspec specification (in Ruby) to the gem home's specifications/default directory.

# File lib/rubygems/installer.rb, line 427
def write_default_spec
  File.open(default_spec_file, "w") do |file|
    file.puts spec.to_ruby
  end
end

write_spec() click to toggle source

Writes the .gemspec specification (in Ruby) to the gem home's specifications directory.

# File lib/rubygems/installer.rb, line 413
def write_spec
  open spec_file, 'w' do |file|
    spec.installed_by_version = Gem.rubygems_version

    file.puts spec.to_ruby_for_cache

    file.fsync rescue nil # for filesystems without fsync(2)
  end
end