#!/usr/bin/python # -*- coding: utf-8 -*- # Copyright (C) 2007 Ivan Krstić # Copyright (C) 2007 Tomeu Vizoso # Copyright (C) 2007 One Laptop per Child # # This program is free software; you can redistribute it and/or modify # it under the terms of version 2 of the GNU General Public License (and # no other version) as published by the Free Software Foundation. # # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License # along with this program; if not, write to the Free Software # Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA import os, re, sys, tempfile, glob, time import urllib2 from urllib2 import URLError, HTTPError import subprocess from subprocess import Popen, PIPE, call from sugar import env from sugar import profile class BackupError(Exception): pass class ProtocolVersionError(BackupError): pass class RefusedByServerError(BackupError): pass class ServerTooBusyError(BackupError): pass class TransferError(BackupError): pass class NoPriorBackups(BackupError): pass class BulkRestoreUnavailable(BackupError): pass def check_server_available(server, xo_serial): try: ret = urllib2.urlopen(server + '/available/%s' % xo_serial).read() return 200 except HTTPError, e: # server is there, did not fullfull req # expect 404, 403, 503 as e[1] return e.code except URLError, e: # log it? # print e.reason return -1 def rsync_to_xs(from_path, backup_host, keyfile, user): to_path = backup_host + ':datastore-current' # add a trailing slash to ensure # that we don't generate a subdir # at the remote end. rsync oddities... if not re.compile('/$').search(from_path): from_path = from_path + '/' ssh_shellcmd = '/usr/bin/ssh -F /dev/null -o "PasswordAuthentication no" -o "StrictHostKeyChecking no" -i "%s" -l "%s"' \ % (keyfile, user) rsync_cmd = ['/usr/bin/rsync', '-z', '-rlt', '--partial', '--delete', '--timeout=160', '-e', ssh_shellcmd, from_path, to_path] #print rsync rsync_exit = call(rsync_cmd) # TODO: we could track progress with a # for line in pipe: # (an earlier version had it) if rsync_exit != 0: # TODO: retry a couple of times # if rsync_exit is 30 (Timeout in data send/receive) raise TransferError('rsync error code %s' % rsync_exit) # Transfer an empty file marking completion # so the XS can see we are done. # Note: the dest dir on the XS is watched via # inotify - so we avoid creating tempfiles there. tmpfile = tempfile.mkstemp() rsync_cmd = ['/usr/bin/rsync', '-z', '-rlt', '--timeout', '10', '-T', '/tmp', '-e', ssh_shellcmd, tmpfile[1], backup_host + ':/var/lib/ds-backup/completion/'+user] rsync_exit = call(rsync_cmd) if rsync_exit != 0: # TODO: retry a couple of times # if rsync_exit is 30 (Timeout in data send/receive) raise TransferError('rsync error code %s.' % rsync_exit) def get_sn(): if have_ofw_tree(): return read_ofw('mfg-data/SN') # on SoaS try gconf, 'identifiers' sn = gconf_get_string('/desktop/sugar/soas_serial') if sn: return sn sn = identifier_get_string('sn') if sn: return sn return 'SHF00000000' def get_backup_url(): bu = gconf_get_string('/desktop/sugar/backup_url') if bu: return bu try: # pre-gconf from iniparse import INIConfig conf = INIConfig(open(os.path.expanduser('~')+'/.sugar/default/config')) # this access mode throws an exception if the value # does not exist bu = conf['Server']['backup1'] except: pass if bu: return bu bu = identifier_get_string('backup_url') if bu: return bu return '' def gconf_get_string(key): """We cannot use python gconf from cron scripts, but cli gconftool-2 does the trick. Will throw subprocess.Popen exceptions""" try: value = Popen(['gconftool-2', '-g', key], stdout=PIPE).communicate()[0] return value except: return '' def identifier_get_string(key): """This is a config method used by some versions of Sugar -- in use in some SoaS""" try: fpath = os.path.expanduser('~')+'/.sugar/default/identifiers/'+key fh = open(fpath, 'r') value = fh.read().rstrip('\0\n') fh.close() return value except: return '' def have_ofw_tree(): return os.path.exists('/ofw') def read_ofw(path): path = os.path.join('/ofw', path) if not os.path.exists(path): return None fh = open(path, 'r') data = fh.read().rstrip('\0\n') fh.close() return data # if run directly as script if __name__ == "__main__": backup_host = '' # host backup_url = '' # target rsync url - set at reg time backup_ctrl_url = '' # http address for control proto ## idmgr (on XS 0.6 and earlier) ## sets backup_url at regtime to ## username@fqdn:backup - but expects the ## rsync cmd to go to username@fqdn:datastore-current ## -- so we only read the FQDN from the value. backup_url = get_backup_url() if not backup_url: # not registered, nothing to do! # (normally caught in ds-backup.sh) exit(0) # matches the host part in # - user@host:path # - host:path m = re.match('(\w+\@)?(\w|.+?):', backup_url) if not m or not m.group(2): sys.stderr.write("Cannot extract backup host from %s\n" % backup_url) exit(1) backup_host = m.group(2) backup_ctrl_url = 'http://' + backup_host + '/backup/1' sn = get_sn() ds_path = env.get_profile_path('datastore') pk_path = os.path.join(env.get_profile_path(), 'owner.key') # Check backup server availability. # On 503 ("too busy") apply exponential back-off # over 10 attempts. Combined with the staggered sleep # in ds-backup.sh, this should keep thundering herds # under control. We are also holding a flock to prevent # local races. # With range(1,7) we sleep up to 64 minutes. for n in range(1,7): sstatus = check_server_available(backup_ctrl_url, sn) if (sstatus == 200): # cleared to run rsync_to_xs(ds_path, backup_host, pk_path, sn) # this marks success to the controlling script... os.system('touch ~/.sugar/default/ds-backup-done') exit(0) elif (sstatus == 503): # exponenxtial backoff time.sleep(60 * 2**n) elif (sstatus == -1): # could not connect - XS is not there exit(1) else: # 500, 404, 403, or other unexpected value exit(sstatus)