snapshot-clean: cleanup old snapshot for zfs

snapshot-clean.rb

#!/usr/local/bin/ruby18
#
# snapshot-clean: cleanup old snapshot for zfs
#
# Usage:
#   snapshot-clean
#
# Copyright(C) 2010 Munechika Sumikawa <[email protected]>, All rights reserved.
# This is free software with ABSOLUTELY NO WARRANTY.
#
# This program was derived from pdumpfs-clean
# Copyright (C) 2003 Taku YASUI <[email protected]>
#
# You can redistribute it and/or modify it under the terms of 
# the GNU General Public License version 2.
#

require 'getoptlong'
require 'date'
require 'ftools'

DEFAULT = { 'year' => 2,
	    'month' => 6,
	    'week' => 6,
	    'day' => 7 }

def parse_options
  options = Hash.new
  parser = GetoptLong.new
  parser.set_options(['--help',          '-h', GetoptLong::NO_ARGUMENT],
		     ['--no-act',	 '-n', GetoptLong::NO_ARGUMENT],
		     ['--verbose',	 '-v', GetoptLong::NO_ARGUMENT],
		     ['--version',	 '-V', GetoptLong::NO_ARGUMENT],
		     ['--keep',		 '-k', GetoptLong::REQUIRED_ARGUMENT])
  parser.each_option {|name, arg|
    options[name.sub(/^--/, "")] = arg
  }
  show_version if options['version']
  show_usage if options['help']
  return options
end

def parse_keep(keep)
  ch_tables = { 'year' => /(\d+)Y/,
  		'month' => /(\d+)M/,
		'week' => /(\d+)W/,
		'day' => /(\d+)D/ }
  ret = {}
  ch_tables.each do |key, regex|
    ret[key] = DEFAULT[key]
    ret[key] = $1.to_i if ( regex.match(keep) )
    ret[key] -= 1
  end
  return ret
end

def create_keepdirs(keep)
  nowdate = Date.new(Time.now.year, Time.now.month, Time.now.day)
  ret = []
  # year
  keep['year'].downto(0) do |i|
    ret.push("#{Time.now.year-i}0101")
  end
  # month  
  keep['month'].downto(0) do |i|
    date = nowdate << i
    ret.push("#{date.year}#{sprintf("%02d", date.month)}01")
  end
  # week
  keep['week'].downto(0) do |i|
  date = nowdate - nowdate.cwday - 7 * i
    ret.push("#{date.year}#{sprintf("%02d", date.month)}#{sprintf("%02d", date.day)}")
  end
  # day
  keep['day'].downto(0) do |i|
    date = nowdate - i
    ret.push("#{date.year}#{sprintf("%02d", date.month)}#{sprintf("%02d", date.day)}")
  end
  ret.sort.uniq
end 

def show_usage
  print <<_EOT
Usage: snapshot-clean [OPTIONS]
OPTIONS:
  --help,              -h: show this help
  --keep KEEPARGS,     -k: use KEEPARGS to decide delete directories
  --no-act,            -n: run command but don't do it
  --verbose,           -v: verbose output
  --version,           -V: show software version
KEEPARGS: [digitY][digitM][digitW][digitD]
  ex: --keep 2Y6M6W7D (2years, 6months, 6weeks, 7days, default)
_EOT
  exit
end

def show_version
  print <<_EOT
snapshot-clean
Copyright (C) 2010 Munechika Sumikawa <[email protected]>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or (at
your option) any later version.

This program was derived from pdumpfs-clean
Copyright (C) 2003 Taku YASUI <[email protected]>
_EOT
  exit
end

def main

  opts = parse_options
  keepdirs = create_keepdirs(parse_keep(opts['keep']))
  keeped = []

  open "| /sbin/zfs list -t snapshot | awk '{print $1}' | grep -v '^NAME'" do |snapshot|
   snapshot.each_line do |line|
    line =~ /([\w\/]+)@([0-9][0-9][0-9][0-9][0-1][0-9][0-3][0-9])/
      if ( $2 == nil or keepdirs.index($2))
        keeped.push(line)
        next
      end
      print "Deleting ", line.chop, " ..." if ( opts['verbose'] )
      system('/sbin/zfs', 'destroy', line.chop) if ( ! opts['no-act'] )
      print " done.\n" if ( opts['verbose'] )
    end
  end
  if ( opts['verbose'] )
    puts "Keep snapshots:"
    keeped.each do |dir|
      puts dir
    end
  end

end

main if __FILE__ == $0