Watch a local folder and synchronize it with a remote folder over SCP

watch.rb

#!/usr/bin/env ruby

require 'rubygems'
require 'rb-fsevent'
require 'optparse'
require 'net/ssh'
require 'net/sftp'

def watch_directory(sftp, watch_dir, target_dir)
  fsevent = FSEvent.new
  fsevent.watch [watch_dir] do |directories|
    directories.each do |dir|
      unless dir.include? ".git"
        sync_directory sftp, dir, dir.gsub(watch_dir, target_dir)
      end
    end
  end

  fsevent.run
end

def sync_directory(sftp, local_dir, remote_dir)
  remote_files = {}

  # collect remote mtimes
  sftp.dir.foreach remote_dir do |f| 
    remote_files[f.name] = f.attributes.mtime
  end

  # check local mtimes
  Dir.foreach(local_dir) do |local_file|
    f = "#{local_dir}#{local_file}"

    if File.file?(f) and (!remote_files.key? local_file or remote_files[local_file] < File.mtime(f).to_i)
      print "#{f} changed, sending... "
      timer = Time.now

      begin
        sftp.upload! f, "#{remote_dir}#{local_file}"
        puts " done in #{(Time.now - timer)*1000}ms"
      rescue Exception => e
        puts " failed! #{e.message}"
      end
    end
  end
end

options = { :verbose=>false, :git=>false }

OptionParser.new do |opts|
  opts.banner = "Usage: watch.rb user@host:path [options]"

  opts.on("-v", "--[no-]verbose", "Run verbosely") do |v|
    options[:verbose] = v
  end

  opts.on("-g", "--git", "Sync the remote side to the current git HEAD") do |g|
    options[:git] = g
  end
end.parse!

remote_user = ARGV[0].split('@').first
remote_host = ARGV[0].split('@').last.split(':').first
watch_dir = File.expand_path(ARGV[0].split('@').last.split(':').last)
remote_dir = "/home/#{remote_user}/"+File.basename(watch_dir)

Net::SSH.start(remote_host, remote_user) do |session|
  if options[:git] 
    branch = `cd #{watch_dir}; git name-rev --name-only HEAD`.chomp
    sha1 = `cd #{watch_dir}; git rev-parse HEAD`.chomp

    puts "Cleaning remote repo"
    session.exec! "git clean -d #{remote_dir}"

    puts "Synchronizing remote to #{branch}@#{sha1}"
    ["git fetch", "git checkout #{branch}", "git reset --hard #{sha1}", "git submodule update --init"].each do |c|
       session.exec! "cd #{remote_dir}; #{c}"
    end

    puts "Sending changed files from local repo"
    puts `cd #{watch_dir}; git status -s -u --ignore-submodules`.chomp

  end

  puts "Listening for changes in #{watch_dir}"
  watch_directory session.sftp, watch_dir, remote_dir
end