RSync snapshot

rsync-snapshot.rb

#!/usr/bin/env ruby
require 'fileutils'

load '/etc/rsync-snapshot.conf'

def protect
	if File.exists? LOCK_FILE
		print "#{$0} already running\n"
		exit -1
	end
	File.new LOCK_FILE, 'w'
	%w(INT TERM QUIT).each { |s| Signal.trap(s) { deprotect } }
end

def deprotect
	File.delete LOCK_FILE if File.exists? LOCK_FILE
end

def rsync(from, to)
	cmd = %w(/usr/bin/rsync -auxHhEAX --delete --ignore-errors)
	exclude = File.join from, EXCLUDE_FILE
	cmd += ['--exclude-from', exclude] if File.exists? exclude
	cmd += [from, to]
	system *cmd
end

def save(name, folder)
	directory = File.join SNAPSHOT_DIR, name
	FileUtils.makedirs directory unless Dir.exists? directory
	
	to = File.join directory, Time.new.strftime('%Y-%m-%d')
	FileUtils.remove_dir to if Dir.exists? to
	
	old = Dir.entries(directory).reject { |name| %w(. ..).include? name }.sort
	until old.size < SIZE
		first = old.shift
		FileUtils.remove_dir File.join directory, first
	end
	
	last = old.pop
	system '/bin/cp', '-al', File.join(directory, last), to unless last.nil?
	
# 	rsync folder, to
end

unless Dir.exists? SNAPSHOT_DIR
	print "#{SNAPSHOT_DIR} not existing\n"
	exit -1
end

protect

processes = []
BACKUP.each do |name, folder|
	p name, folder
	if Dir.exists? folder
		processes << Thread.new { save name, folder }
	end
end

processes.each { |p| p.join }

deprotect

rsync-snapshot.conf

SNAPSHOT_DIR = '/mnt/backup/snapshots'
LOCK_FILE = "#{SNAPSHOT_DIR}/rsync-snapshot.lock"

SIZE = 52

EXCLUDE_FILE = '.rsync-snapshot.ignore';

BACKUP = {
	'aeris' => '/home/aeris/'
}