qemu-backup will be a command-line tool for performing full and incremental disk backups on running VMs. It is intended as a reference implementation for management stack and backup developers to see QEMU's backup features in action. The tool writes details of guest in a configuration file and the data is retrieved from the file while creating a backup. The location of config file can be set as an environment variable QEMU_BACKUP_CONFIG. The usage is as follows:
Add a guest python qemu-backup.py guest add --guest <guest_name> --qmp <socket_path> Add a drive for backup in a specified guest python qemu-backup.py drive add --guest <guest_name> --id <drive_id> [--target <target_file_path>] Create backup of the added drives: python qemu-backup.py backup --guest <guest_name> List all guest configs in configuration file: python qemu-backup.py guest list Restore operation python qemu-backup.py restore --guest <guest-name> Remove a guest python qemu-backup.py guest remove --guest <guest_name> Signed-off-by: Ishani Chugh <chugh.ish...@research.iiit.ac.in> --- contrib/backup/qemu-backup.py | 217 +++++++++++++++++++++++++++--------------- 1 file changed, 141 insertions(+), 76 deletions(-) diff --git a/contrib/backup/qemu-backup.py b/contrib/backup/qemu-backup.py index 9c3dc53..9bbbdb7 100644 --- a/contrib/backup/qemu-backup.py +++ b/contrib/backup/qemu-backup.py @@ -1,22 +1,54 @@ #!/usr/bin/python # -*- coding: utf-8 -*- +# +# Copyright (C) 2013 Red Hat, Inc. +# +# 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 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, see <http://www.gnu.org/licenses/>. +# + """ This file is an implementation of backup tool """ +from __future__ import print_function from argparse import ArgumentParser import os import errno from socket import error as socket_error -import configparser +try: + import configparser +except ImportError: + import ConfigParser as configparser import sys -sys.path.append('../../scripts/qmp') +sys.path.append(os.path.join(os.path.dirname(__file__), '..', '..', + 'scripts', 'qmp')) from qmp import QEMUMonitorProtocol class BackupTool(object): """BackupTool Class""" - def __init__(self, config_file='backup.ini'): - self.config_file = config_file + def __init__(self, + config_file=os.path.expanduser('~')+'/.qemu/backup/config'): + if "QEMU_BACKUP_CONFIG" in os.environ: + self.config_file = os.environ["QEMU_BACKUP_CONFIG"] + else: + self.config_file = config_file + try: + if not os.path.isdir(os.path.expanduser('~')+'/.qemu/backup'): + os.makedirs(os.path.expanduser('~')+'/.qemu/backup') + except: + print("Cannot find the config file", file=sys.stderr) + exit(1) self.config = configparser.ConfigParser() self.config.read(self.config_file) @@ -24,66 +56,70 @@ class BackupTool(object): """ Writes configuration to ini file. """ - with open(self.config_file, 'w') as config_file: - self.config.write(config_file) + config_file = open(self.config_file+".tmp", 'w') + self.config.write(config_file) + config_file.flush() + os.fsync(config_file.fileno()) + config_file.close() + os.rename(self.config_file+".tmp", self.config_file) - def get_socket_path(self, socket_path, tcp): + def get_socket_address(self, socket_address): """ Return Socket address in form of string or tuple """ - if tcp is False: - return os.path.abspath(socket_path) - return (socket_path.split(':')[0], int(socket_path.split(':')[1])) + if socket_address.startswith('tcp'): + return (socket_address.split(':')[1], + int(socket_address.split(':')[2])) + return socket_address.split(':',2)[1] - def __full_backup(self, guest_name): + def _full_backup(self, guest_name): """ Performs full backup of guest """ if guest_name not in self.config.sections(): - print ("Cannot find specified guest") - return - if self.is_guest_running(guest_name, self.config[guest_name]['qmp'], - self.config[guest_name]['tcp']) is False: - return + print ("Cannot find specified guest", file=sys.stderr) + exit(1) + + self.verify_guest_running(guest_name) connection = QEMUMonitorProtocol( - self.get_socket_path( - self.config[guest_name]['qmp'], - self.config[guest_name]['tcp'])) + self.get_socket_address( + self.config[guest_name]['qmp'])) connection.connect() cmd = {"execute": "transaction", "arguments": {"actions": []}} for key in self.config[guest_name]: if key.startswith("drive_"): - drive = key[key.index('_')+1:] + drive = key[len('drive_'):] target = self.config[guest_name][key] sub_cmd = {"type": "drive-backup", "data": {"device": drive, "target": target, "sync": "full"}} cmd['arguments']['actions'].append(sub_cmd) - print (connection.cmd_obj(cmd)) + connection.cmd_obj(cmd) + if connection.pull_event(wait=True)['event'] == 'BLOCK_JOB_COMPLETED': + print("Backup Complete") + else: + print("Cannot complete backup", file=sys.stderr) - def __drive_add(self, drive_id, guest_name, target=None): + def _drive_add(self, drive_id, guest_name, target=None): """ Adds drive for backup """ if target is None: - target = os.path.abspath(drive_id) + ".img" + target = os.path.abspath(drive_id) if guest_name not in self.config.sections(): - print ("Cannot find specified guest") - return + print ("Cannot find specified guest", file=sys.stderr) + exit(1) if "drive_"+drive_id in self.config[guest_name]: - print ("Drive already marked for backup") - return + print ("Drive already marked for backup", file=sys.stderr) + exit(1) - if self.is_guest_running(guest_name, self.config[guest_name]['qmp'], - self.config[guest_name]['tcp']) is False: - return + self.verify_guest_running(guest_name) connection = QEMUMonitorProtocol( - self.get_socket_path( - self.config[guest_name]['qmp'], - self.config[guest_name]['tcp'])) + self.get_socket_address( + self.config[guest_name]['qmp'])) connection.connect() cmd = {'execute': 'query-block'} returned_json = connection.cmd_obj(cmd) @@ -93,69 +129,93 @@ class BackupTool(object): device_present = True break - if device_present is False: - print ("No such drive in guest") - return + if not device_present: + print ("No such drive in guest", file=sys.stderr) + sys.exit(1) drive_id = "drive_" + drive_id - for id in self.config[guest_name]: - if self.config[guest_name][id] == target: - print ("Please choose different target") - return + for d_id in self.config[guest_name]: + if self.config[guest_name][d_id] == target: + print ("Please choose different target", file=sys.stderr) + exit(1) self.config.set(guest_name, drive_id, target) self.write_config() print("Successfully Added Drive") - def is_guest_running(self, guest_name, socket_path, tcp): + def verify_guest_running(self, guest_name): """ Checks whether specified guest is running or not """ + socket_address = self.config.get(guest_name, 'qmp') try: - connection = QEMUMonitorProtocol( - self.get_socket_path( - socket_path, tcp)) + connection = QEMUMonitorProtocol(self.get_socket_address( + socket_address)) connection.connect() except socket_error: if socket_error.errno != errno.ECONNREFUSED: - print ("Connection to guest refused") - return False - except: - print ("Unable to connect to guest") - return False - return True + print ("Connection to guest refused", file=sys.stderr) + sys.exit(1) - def __guest_add(self, guest_name, socket_path, tcp): + def _guest_add(self, guest_name, socket_address): """ Adds a guest to the config file """ - if self.is_guest_running(guest_name, socket_path, tcp) is False: - return - if guest_name in self.config.sections(): - print ("ID already exists. Please choose a different guestname") - return - - self.config[guest_name] = {'qmp': socket_path} - self.config.set(guest_name, 'tcp', str(tcp)) + print ("ID already exists. Please choose a different guestname", + file=sys.stderr) + sys.exit(1) + self.config[guest_name] = {'qmp': socket_address} + self.verify_guest_running(guest_name) self.write_config() print("Successfully Added Guest") - def __guest_remove(self, guest_name): + def _guest_remove(self, guest_name): """ Removes a guest from config file """ if guest_name not in self.config.sections(): - print("Guest Not present") - return + print("Guest Not present", file=sys.stderr) + sys.exit(1) self.config.remove_section(guest_name) print("Guest successfully deleted") + def _restore(self, guest_name): + """ + Prints Steps to perform restore operation + """ + if guest_name not in self.config.sections(): + print ("Cannot find specified guest", file=sys.stderr) + exit(1) + + self.verify_guest_running(guest_name) + connection = QEMUMonitorProtocol( + self.get_socket_address( + self.config[guest_name]['qmp'])) + connection.connect() + print("To perform restore, replace:") + for key in self.config[guest_name]: + if key.startswith("drive_"): + drive = key[len('drive_'):] + target = self.config[guest_name][key] + cmd = {'execute': 'query-block'} + returned_json = connection.cmd_obj(cmd) + device_present = False + for device in returned_json['return']: + if device['device'] == drive: + device_present = True + location = device['inserted']['image']['filename'] + print(location+" By "+target) + + if not device_present: + print ("No such drive in guest", file=sys.stderr) + sys.exit(1) + def guest_remove_wrapper(self, args): """ - Wrapper for __guest_remove method. + Wrapper for _guest_remove method. """ guest_name = args.guest - self.__guest_remove(guest_name) + self._guest_remove(guest_name) self.write_config() def list(self, args): @@ -167,24 +227,27 @@ class BackupTool(object): def guest_add_wrapper(self, args): """ - Wrapper for __quest_add method + Wrapper for _quest_add method """ - if args.tcp is False: - self.__guest_add(args.guest, args.qmp, False) - else: - self.__guest_add(args.guest, args.qmp, True) + self._guest_add(args.guest, args.qmp) def drive_add_wrapper(self, args): """ - Wrapper for __drive_add method + Wrapper for _drive_add method """ - self.__drive_add(args.id, args.guest, args.target) + self._drive_add(args.id, args.guest, args.target) def fullbackup_wrapper(self, args): """ - Wrapper for __full_backup method + Wrapper for _full_backup method """ - self.__full_backup(args.guest) + self._full_backup(args.guest) + + def restore_wrapper(self, args): + """ + Wrapper for restore + """ + self._restore(args.guest) def main(): @@ -205,9 +268,6 @@ def main(): help='Name of the guest') guest_add_parser.add_argument('--qmp', action='store', type=str, help='Path of socket') - guest_add_parser.add_argument('--tcp', nargs='?', type=bool, - default=False, - help='Specify if socket is tcp') guest_add_parser.set_defaults(func=backup_tool.guest_add_wrapper) guest_remove_parser = guest_subparsers.add_parser('remove', @@ -237,6 +297,11 @@ def main(): type=str, help='Name of the guest') backup_parser.set_defaults(func=backup_tool.fullbackup_wrapper) + backup_parser = subparsers.add_parser('restore', help='Restores drives') + backup_parser.add_argument('--guest', action='store', + type=str, help='Name of the guest') + backup_parser.set_defaults(func=backup_tool.restore_wrapper) + args = parser.parse_args() args.func(args) -- 2.7.4
