git-serve.rb

#!/usr/bin/env ruby

require 'fileutils'
require 'singleton'

class Gitster
  include Singleton
  
  def initialize
    @created_flags = []
    @repositories = []
  end
  
  def add_repository(repo)
    return unless git_repo?(repo)
    create_flag_unless_it_already_exists_for(repo)
    @repositories << File.basename(repo)
  end
  
  def serve(dir = Dir.pwd)
    if @repositories.empty?
      raise "No repositories to serve"
    end
    cmd = "git daemon --base-path=#{dir}"
    puts "Serving: #{@repositories.join(", ")}"
    `#{cmd}`
  end
  
  def cleanup
    @created_flags.each do |flag|
      File.delete(flag)
    end
  end
  
  private
  
  def git_repo?(dir)
    File.exist?(File.join(dir, ".git"))
  end
  
  def create_flag_unless_it_already_exists_for(repo)
    flag = File.join(repo, ".git", "git-daemon-export-ok")
    unless File.exist?(flag)
      FileUtils.touch(flag)
      @created_flags << flag
    end
  end
end

gitster = Gitster.instance

Signal.trap('INT') do
  puts "Cleaning up"
  gitster.cleanup
  exit 0
end

if ARGV.any?
  ARGV.each { |repo| gitster.add_repository(File.join(Dir.pwd, repo)) }
  gitster.serve
else
  gitster.add_repository(Dir.pwd)
  gitster.serve(File.expand_path(File.join(Dir.pwd, "..")))
end