Gem::Server and allows users to serve gems for consumption by `gem --remote-install`.
gem_server starts an HTTP server on the given port and serves the following:
“/” - Browsing of gem spec files for installed gems
“/specs.#{Gem.marshal_version}.gz” - specs name/version/platform index
“/latest_specs.#{Gem.marshal_version}.gz” - latest specs name/version/platform index
“/quick/” - Individual gemspecs
“/gems” - Direct access to download the installable gems
“/rdoc?q=” - Search for installed rdoc documentation
gem_server = Gem::Server.new Gem.dir, 8089, false gem_server.run
CSS is copy & paste from rdoc-style.css, RDoc V1.0.1 - 20041108
 
               # File rubygems/server.rb, line 432
def initialize(gem_dirs, port, daemon, launch = nil, addresses = nil)
  Gem::RDoc.load_rdoc
  Socket.do_not_reverse_lookup = true
  @gem_dirs  = Array gem_dirs
  @port      = port
  @daemon    = daemon
  @launch    = launch
  @addresses = addresses
  logger  = WEBrick::Log.new nil, WEBrick::BasicLog::FATAL
  @server = WEBrick::HTTPServer.new :DoNotListen => true, :Logger => logger
  @spec_dirs = @gem_dirs.map { |gem_dir| File.join gem_dir, 'specifications' }
  @spec_dirs.reject! { |spec_dir| !File.directory? spec_dir }
  reset_gems
  @have_rdoc_4_plus = nil
end
             
             
               # File rubygems/server.rb, line 453
def add_date(res)
  res['date'] = @spec_dirs.map do |spec_dir|
    File.stat(spec_dir).mtime
  end.max
end
             
             
               # File rubygems/server.rb, line 465
def doc_root(gem_name)
  if have_rdoc_4_plus?
    "/doc_root/#{u gem_name}/"
  else
    "/doc_root/#{u gem_name}/rdoc/index.html"
  end
end
             
             
               # File rubygems/server.rb, line 473
def have_rdoc_4_plus?
  @have_rdoc_4_plus ||=
    Gem::Requirement.new('>= 4.0.0.preview2').satisfied_by? Gem::RDoc.rdoc_version
end
             
             
               # File rubygems/server.rb, line 478
def latest_specs(req, res)
  reset_gems
  res['content-type'] = 'application/x-gzip'
  add_date res
  latest_specs = Gem::Specification.latest_specs
  specs = latest_specs.sort.map do |spec|
    platform = spec.original_platform || Gem::Platform::RUBY
    [spec.name, spec.version, platform]
  end
  specs = Marshal.dump specs
  if req.path =~ /\.gz$/
    specs = Gem::Util.gzip specs
    res['content-type'] = 'application/x-gzip'
  else
    res['content-type'] = 'application/octet-stream'
  end
  if req.request_method == 'HEAD'
    res['content-length'] = specs.length
  else
    res.body << specs
  end
end
             
             
               # File rubygems/server.rb, line 868
def launch
  listeners = @server.listeners.map{|l| l.addr[2] }
  # TODO: 0.0.0.0 == any, not localhost.
  host = listeners.any?{|l| l == '0.0.0.0'} ? 'localhost' : listeners.first
  say "Launching browser to http://#{host}:#{@port}"
  system("#{@launch} http://#{host}:#{@port}")
end
             
            Creates server sockets based on the addresses option. If no addresses were given a server socket for all interfaces is created.
 
               # File rubygems/server.rb, line 512
def listen(addresses = @addresses)
  addresses = [nil] unless addresses
  listeners = 0
  addresses.each do |address|
    begin
      @server.listen address, @port
      @server.listeners[listeners..-1].each do |listener|
        host, port = listener.addr.values_at 2, 1
        host = "[#{host}]" if host =~ /:/ # we don't reverse lookup
        say "Server started at http://#{host}:#{port}"
      end
      listeners = @server.listeners.length
    rescue SystemCallError
      next
    end
  end
  if @server.listeners.empty?
    say "Unable to start a server."
    say "Check for running servers or your --bind and --port arguments"
    terminate_interaction 1
  end
end
             
             
               # File rubygems/server.rb, line 539
def prerelease_specs(req, res)
  reset_gems
  res['content-type'] = 'application/x-gzip'
  add_date res
  specs = Gem::Specification.select do |spec|
    spec.version.prerelease?
  end.sort.map do |spec|
    platform = spec.original_platform || Gem::Platform::RUBY
    [spec.name, spec.version, platform]
  end
  specs = Marshal.dump specs
  if req.path =~ /\.gz$/
    specs = Gem::Util.gzip specs
    res['content-type'] = 'application/x-gzip'
  else
    res['content-type'] = 'application/octet-stream'
  end
  if req.request_method == 'HEAD'
    res['content-length'] = specs.length
  else
    res.body << specs
  end
end
             
             
               # File rubygems/server.rb, line 569
def quick(req, res)
  reset_gems
  res['content-type'] = 'text/plain'
  add_date res
  case req.request_uri.path
  when %r|^/quick/(Marshal.#{Regexp.escape Gem.marshal_version}/)?(.*?)\.gemspec\.rz$| then
    marshal_format, full_name = $1, $2
    specs = Gem::Specification.find_all_by_full_name(full_name)
    selector = full_name.inspect
    if specs.empty?
      res.status = 404
      res.body = "No gems found matching #{selector}"
    elsif specs.length > 1
      res.status = 500
      res.body = "Multiple gems found matching #{selector}"
    elsif marshal_format
      res['content-type'] = 'application/x-deflate'
      res.body << Gem.deflate(Marshal.dump(specs.first))
    end
  else
    raise WEBrick::HTTPStatus::NotFound, "`#{req.path}' not found."
  end
end
             
            Can be used for quick navigation to the rdoc documentation. You can then define a search shortcut for your browser. E.g. in Firefox connect ‘shortcut:rdoc’ to localhost:8808/rdoc?q=%s template. Then you can directly open the ActionPack documentation by typing ‘rdoc actionp’. If there are multiple hits for the search term, they are presented as a list with links.
Search algorithm aims for an intuitive search:
first try to find the gems and documentation folders which name starts with the search term
search for entries, that contain the search term
show all the gems
If there is only one search hit, user is immediately redirected to the documentation for the particular gem, otherwise a list with results is shown.
Note: please adjust paths accordingly use for example ‘locate yaml.rb’ and ‘gem environment’ to identify directories, that are specific for your local installation
install Ruby sources
cd /usr/src sudo apt-get source ruby
generate documentation
rdoc -o /usr/lib/ruby/gems/1.8/doc/core/rdoc \ /usr/lib/ruby/1.8 ruby1.8-1.8.7.72
By typing ‘rdoc core’ you can now access the core documentation
 
               # File rubygems/server.rb, line 730
def rdoc(req, res)
  query = req.query['q']
  show_rdoc_for_pattern("#{query}*", res) && return
  show_rdoc_for_pattern("*#{query}*", res) && return
  template = ERB.new RDOC_NO_DOCUMENTATION
  res['content-type'] = 'text/html'
  res.body = template.result binding
end
             
             
               # File rubygems/server.rb, line 597
def root(req, res)
  reset_gems
  add_date res
  raise WEBrick::HTTPStatus::NotFound, "`#{req.path}' not found." unless
    req.path == '/'
  specs = []
  total_file_count = 0
  Gem::Specification.each do |spec|
    total_file_count += spec.files.size
    deps = spec.dependencies.map do |dep|
      {
        "name"    => dep.name,
        "type"    => dep.type,
        "version" => dep.requirement.to_s,
      }
    end
    deps = deps.sort_by { |dep| [dep["name"].downcase, dep["version"]] }
    deps.last["is_last"] = true unless deps.empty?
    # executables
    executables = spec.executables.sort.collect { |exec| {"executable" => exec} }
    executables = nil if executables.empty?
    executables.last["is_last"] = true if executables
    # Pre-process spec homepage for safety reasons
    begin
      homepage_uri = URI.parse(spec.homepage)
      if [URI::HTTP, URI::HTTPS].member? homepage_uri.class
        homepage_uri = spec.homepage
      else
        homepage_uri = "."
      end
    rescue URI::InvalidURIError
      homepage_uri = "."
    end
    specs << {
      "authors"             => spec.authors.sort.join(", "),
      "date"                => spec.date.to_s,
      "dependencies"        => deps,
      "doc_path"            => doc_root(spec.full_name),
      "executables"         => executables,
      "only_one_executable" => (executables && executables.size == 1),
      "full_name"           => spec.full_name,
      "has_deps"            => !deps.empty?,
      "homepage"            => homepage_uri,
      "name"                => spec.name,
      "rdoc_installed"      => Gem::RDoc.new(spec).rdoc_installed?,
      "ri_installed"        => Gem::RDoc.new(spec).ri_installed?,
      "summary"             => spec.summary,
      "version"             => spec.version.to_s,
    }
  end
  specs << {
    "authors" => "Chad Fowler, Rich Kilmer, Jim Weirich, Eric Hodel and others",
    "dependencies" => [],
    "doc_path" => doc_root("rubygems-#{Gem::VERSION}"),
    "executables" => [{"executable" => 'gem', "is_last" => true}],
    "only_one_executable" => true,
    "full_name" => "rubygems-#{Gem::VERSION}",
    "has_deps" => false,
    "homepage" => "https://guides.rubygems.org/",
    "name" => 'rubygems',
    "ri_installed" => true,
    "summary" => "RubyGems itself",
    "version" => Gem::VERSION,
  }
  specs = specs.sort_by { |spec| [spec["name"].downcase, spec["version"]] }
  specs.last["is_last"] = true
  # tag all specs with first_name_entry
  last_spec = nil
  specs.each do |spec|
    is_first = last_spec.nil? || (last_spec["name"].downcase != spec["name"].downcase)
    spec["first_name_entry"] = is_first
    last_spec = spec
  end
  # create page from template
  template = ERB.new(DOC_TEMPLATE)
  res['content-type'] = 'text/html'
  values = { "gem_count" => specs.size.to_s, "specs" => specs,
             "total_file_count" => total_file_count.to_s }
  # suppress 1.9.3dev warning about unused variable
  values = values
  result = template.result binding
  res.body = result
end
             
             
               # File rubygems/server.rb, line 787
def run
  listen
  WEBrick::Daemon.start if @daemon
  @server.mount_proc "/specs.#{Gem.marshal_version}", method(:specs)
  @server.mount_proc "/specs.#{Gem.marshal_version}.gz", method(:specs)
  @server.mount_proc "/latest_specs.#{Gem.marshal_version}",
                     method(:latest_specs)
  @server.mount_proc "/latest_specs.#{Gem.marshal_version}.gz",
                     method(:latest_specs)
  @server.mount_proc "/prerelease_specs.#{Gem.marshal_version}",
                     method(:prerelease_specs)
  @server.mount_proc "/prerelease_specs.#{Gem.marshal_version}.gz",
                     method(:prerelease_specs)
  @server.mount_proc "/quick/", method(:quick)
  @server.mount_proc("/gem-server-rdoc-style.css") do |req, res|
    res['content-type'] = 'text/css'
    add_date res
    res.body << RDOC_CSS
  end
  @server.mount_proc "/", method(:root)
  @server.mount_proc "/rdoc", method(:rdoc)
  file_handlers = {
    '/gems' => '/cache/',
  }
  if have_rdoc_4_plus?
    @server.mount '/doc_root', RDoc::Servlet, '/doc_root'
  else
    file_handlers['/doc_root'] = '/doc/'
  end
  @gem_dirs.each do |gem_dir|
    file_handlers.each do |mount_point, mount_dir|
      @server.mount(mount_point, WEBrick::HTTPServlet::FileHandler,
                    File.join(gem_dir, mount_dir), true)
    end
  end
  trap("INT") { @server.shutdown; exit! }
  trap("TERM") { @server.shutdown; exit! }
  launch if @launch
  @server.start
end
             
            Returns true and prepares http response, if rdoc for the requested gem name pattern was found.
The search is based on the file system content, not on the gems metadata. This allows additional documentation folders like ‘core’ for the Ruby core documentation - just put it underneath the main doc folder.
 
               # File rubygems/server.rb, line 756
def show_rdoc_for_pattern(pattern, res)
  found_gems = Dir.glob("{#{@gem_dirs.join ','}}/doc/#{pattern}").select do |path|
    File.exist? File.join(path, 'rdoc/index.html')
  end
  case found_gems.length
  when 0
    return false
  when 1
    new_path = File.basename(found_gems[0])
    res.status = 302
    res['Location'] = doc_root new_path
    return true
  else
    doc_items = []
    found_gems.each do |file_name|
      base_name = File.basename(file_name)
      doc_items << {
        :name    => base_name,
        :url     => doc_root(new_path),
        :summary => ''
      }
    end
    template = ERB.new(RDOC_SEARCH_TEMPLATE)
    res['content-type'] = 'text/html'
    result = template.result binding
    res.body = result
    return true
  end
end
             
             
               # File rubygems/server.rb, line 842
def specs(req, res)
  reset_gems
  add_date res
  specs = Gem::Specification.sort_by(&:sort_obj).map do |spec|
    platform = spec.original_platform || Gem::Platform::RUBY
    [spec.name, spec.version, platform]
  end
  specs = Marshal.dump specs
  if req.path =~ /\.gz$/
    specs = Gem::Util.gzip specs
    res['content-type'] = 'application/x-gzip'
  else
    res['content-type'] = 'application/octet-stream'
  end
  if req.request_method == 'HEAD'
    res['content-length'] = specs.length
  else
    res.body << specs
  end
end