# -*- Mode:Python; indent-tabs-mode:nil; tab-width:4; encoding:utf-8 -*-
#
# Copyright 2020 Jose L. Domingo Lopez <github@24x7linux.com>
#
# This file is part of duplicity.
#
# Duplicity 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.
#
# Duplicity 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 duplicity; if not, write to the Free Software Foundation,
# Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
from __future__ import print_function
import os
import re
import subprocess
import duplicity.backend
from duplicity import util
from duplicity.errors import BackendException
from future import standard_library
standard_library.install_aliases()
[docs]class Megav3Backend(duplicity.backend.Backend):
u"""Backend for MEGA.nz cloud storage, only one that works for accounts created since Nov. 2018
See https://github.com/megous/megatools/issues/411 for more details
This MEGA backend resorts to official tools (MEGAcmd) as available at https://mega.nz/cmd
MEGAcmd works through a single binary called "mega-cmd", which keeps state (for example,
persisting a session). Multiple "mega-*" shell wrappers (ie. "mega-ls") exist as the user
interface to "mega-cmd" and MEGA API
The full MEGAcmd User Guide can be found in the software's GitHub page below :
https://github.com/meganz/MEGAcmd/blob/master/UserGuide.md"""
[docs] def __init__(self, parsed_url):
duplicity.backend.Backend.__init__(self, parsed_url)
# Sanity check : ensure all the necessary "MEGAcmd" binaries exist
self._check_binary_exists(u'mega-cmd')
self._check_binary_exists(u'mega-exec')
self._check_binary_exists(u'mega-help')
self._check_binary_exists(u'mega-get')
self._check_binary_exists(u'mega-login')
self._check_binary_exists(u'mega-logout')
self._check_binary_exists(u'mega-ls')
self._check_binary_exists(u'mega-mkdir')
self._check_binary_exists(u'mega-put')
self._check_binary_exists(u'mega-rm')
self._check_binary_exists(u'mega-whoami')
# "MEGAcmd" does not use a config file, however it is handy to keep one (with the old ".megarc" format) to
# securely store the username and password
self._hostname = parsed_url.hostname
if parsed_url.username is None:
self._megarc = os.getenv(u'HOME') + u'/.megav3rc'
try:
conf_file = open(self._megarc, u"r")
except Exception as e:
raise BackendException(
u"No password provided in URL and MEGA configuration "
u"file for duplicity does not exist as '%s'"
% (self._megarc,)
)
myvars = {}
for line in conf_file:
name, var = line.partition(u"=")[::2]
myvars[name.strip()] = str(var.strip())
conf_file.close()
self._username = myvars[u"Username"]
self._password = myvars[u"Password"]
else:
self._username = parsed_url.username
self._password = parsed_url.password
no_logout_option = parsed_url.query_args.get(u'no_logout', [])
self._no_logout = (len(no_logout_option) > 0) and (
no_logout_option[0].lower() in [u'1', u'yes', u'true']
)
self.ensure_mega_cmd_running()
# Remote folder ("MEGAcmd" no longer shows "Root/" at the top of the hierarchy)
self._folder = u'/' + parsed_url.path[1:]
# Only create the remote folder if it doesn't exist yet
self.mega_login()
cmd = [u'mega-ls', self._folder]
try:
self.subprocess_popen(cmd)
except Exception as e:
self._makedir(self._folder)
[docs] def _check_binary_exists(self, cmd):
u'Checks that a specified command exists in the running user command path'
try:
# Ignore the output, as we only need the return code
subprocess.check_output([u'which', cmd])
except Exception as e:
raise BackendException(
u"Command '%s' not found, make sure 'MEGAcmd' tools (https://mega.nz/cmd) is "
u"properly installed and in the running user command path"
% (cmd,)
)
[docs] def ensure_mega_cmd_running(self):
u'Trigger any mega command to ensure mega-cmd server is running'
try:
subprocess.run(
u"mega-help",
stdout=subprocess.DEVNULL,
stderr=subprocess.DEVNULL,
).check_returncode()
except Exception:
raise BackendException(u'Cannot execute mega command')
[docs] def _makedir(self, path):
u'Creates a remote directory (recursively if necessary)'
self.mega_login()
cmd = [u'mega-mkdir', u'-p', path]
try:
self.subprocess_popen(cmd)
except Exception as e:
error_str = str(e)
if u"Folder already exists" in error_str:
raise BackendException(
u"Folder '%s' could not be created on MEGA because it already exists. "
u"Use another path or remove the folder in MEGA manually"
% (path,)
)
else:
raise BackendException(
u"Folder '%s' could not be created, reason : '%s'"
% (path, e)
)
[docs] def _put(self, source_path, remote_filename):
u"""Uploads file to the specified remote folder (tries to delete it first to make
sure the new one can be uploaded)"""
try:
self.delete(remote_filename.decode())
except Exception:
pass
self.upload(
local_file=source_path.get_canonical().decode(),
remote_file=remote_filename.decode(),
)
[docs] def _get(self, remote_filename, local_path):
u'Downloads file from the specified remote path'
self.download(
remote_file=remote_filename.decode(),
local_file=local_path.name.decode(),
)
[docs] def _list(self):
u'Lists files in the specified remote path'
return self.folder_contents(files_only=True)
[docs] def _delete(self, filename):
u'Deletes file from the specified remote path'
self.delete(remote_file=filename.decode())
[docs] def _close(self):
u'Function called when backend is done being used'
if not self._no_logout:
cmd = [u'mega-logout']
self.subprocess_popen(cmd)
cmd = [u'mega-exec', u'exit']
self.subprocess_popen(cmd)
[docs] def mega_login(self):
u"""Helper function to check existing session exists"""
# Abort if command doesn't return in a reasonable time (somehow "mega-session" sometimes
# doesn't return), and create session if one doesn't exist yet
try:
result = subprocess.run(
u'mega-whoami',
timeout=30,
capture_output=True,
)
result.check_returncode()
current_username = result.stdout.decode().split(u':')[-1].strip()
if current_username != self._username:
raise Exception(u"Username is not match")
except subprocess.TimeoutExpired:
self._close()
raise BackendException(
u"Timed out while trying to determine if a MEGA session exists"
)
except Exception as e:
if self._password is None:
self._password = self.get_password()
cmd = [u'mega-login', self._username, self._password]
try:
subprocess.run(
cmd,
stderr=subprocess.DEVNULL,
).check_returncode()
except Exception as e:
self._close()
raise BackendException(
u"Could not log in to MEGA, error : '%s'" % (e,)
)
[docs] def folder_contents(self, files_only=False):
u'Lists contents of a remote MEGA path, optionally ignoring subdirectories'
cmd = [u'mega-ls', u'-l', self._folder]
self.mega_login()
files = subprocess.check_output(cmd)
files = files.decode().split(u'\n')
# Optionally ignore directories
if files_only:
files = [f.split()[5] for f in files if re.search(u'^-', f)]
return files
[docs] def download(self, remote_file, local_file):
u'Downloads a file from a remote MEGA path'
cmd = [u'mega-get', self._folder + u'/' + remote_file, local_file]
self.mega_login()
self.subprocess_popen(cmd)
[docs] def upload(self, local_file, remote_file):
u'Uploads a file to a remote MEGA path'
cmd = [u'mega-put', local_file, self._folder + u'/' + remote_file]
self.mega_login()
try:
self.subprocess_popen(cmd)
except Exception as e:
error_str = str(e)
if u"Reached storage quota" in error_str:
raise BackendException(
u"MEGA account over quota, could not write file : '%s' . "
u"Upgrade your storage at https://mega.nz/pro or remove some data."
% (remote_file,)
)
else:
raise BackendException(
u"Failed writing file '%s' to MEGA, reason : '%s'"
% (remote_file, e)
)
[docs] def delete(self, remote_file):
u'Deletes a file from a remote MEGA path'
cmd = [u'mega-rm', u'-f', self._folder + u'/' + remote_file]
self.mega_login()
self.subprocess_popen(cmd)
duplicity.backend.register_backend(u'megav3', Megav3Backend)
duplicity.backend.uses_netloc.extend([u'megav3'])