[Qemu-devel] [PATCH 0/3] QEMU Backup Tool

[Qemu-devel] [PATCH 0/3] QEMU Backup Tool

[Ishani Chugh]

This patch series is intended to introduce QEMU Backup tool.
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.
This patch series contains three patches,
               1) QEMU Backup command line tool.
               2) Test for full backup.
               3) Manpage for the tool.

Ishani Chugh (3):
  backup: QEMU Backup Tool
  Test for full Backup
  Add manpage for QEMU Backup Tool

 Makefile                        |  14 +-
 contrib/backup/qemu-backup.py   | 335 ++++++++++++++++++++++++++++++++++++++++
 contrib/backup/qemu-backup.texi | 144 +++++++++++++++++
 tests/qemu-iotests/191          |  86 +++++++++++
 tests/qemu-iotests/191.out      |  35 +++++
 tests/qemu-iotests/group        |   2 +
 6 files changed, 612 insertions(+), 4 deletions(-)
 create mode 100644 contrib/backup/qemu-backup.py
 create mode 100644 contrib/backup/qemu-backup.texi
 create mode 100755 tests/qemu-iotests/191
 create mode 100644 tests/qemu-iotests/191.out

-- 
2.7.4

[Qemu-devel] [PATCH 1/3] backup: QEMU Backup Tool

[Ishani Chugh]

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.ishani@research.iiit.ac.in>
---
 contrib/backup/qemu-backup.py | 335 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 335 insertions(+)
 create mode 100644 contrib/backup/qemu-backup.py

diff --git a/contrib/backup/qemu-backup.py b/contrib/backup/qemu-backup.py
new file mode 100644
index 0000000..c8032de
--- /dev/null
+++ b/contrib/backup/qemu-backup.py
@@ -0,0 +1,335 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+#
+# Copyright (C) 2017 Ishani Chugh <chugh.ishani@research.iiit.ac.in>
+#
+# 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
+try:
+    import configparser
+except ImportError:
+    import ConfigParser as configparser
+import sys
+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=os.path.expanduser('~') +
+                 '/.config/qemu/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.dirname(self.config_file)):
+                    os.makedirs(os.path.dirname(self.config_file))
+            except:
+                print("Cannot create config directory", file=sys.stderr)
+                sys.exit(1)
+        self.config = configparser.ConfigParser()
+        self.config.read(self.config_file)
+
+    def write_config(self):
+        """
+        Writes configuration to ini 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_address(self, socket_address):
+        """
+        Return Socket address in form of string or tuple
+        """
+        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):
+        """
+        Performs full backup of guest
+        """
+        if guest_name not in self.config.sections():
+            print("Cannot find specified guest", file=sys.stderr)
+            sys.exit(1)
+
+        self.verify_guest_running(guest_name)
+        connection = QEMUMonitorProtocol(
+                                         self.get_socket_address(
+                                             self.config[guest_name]['qmp']))
+        connection.connect()
+        cmd = {"execute": "transaction", "arguments": {"actions": []}}
+        drive_list = []
+        for key in self.config[guest_name]:
+            if key.startswith("drive_"):
+                drive = key[len('drive_'):]
+                drive_list.append(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)
+        qmp_return = connection.cmd_obj(cmd)
+        if 'error' in qmp_return:
+            print(qmp_return['error']['desc'], file=sys.stderr)
+            sys.exit(1)
+        print("Backup Started")
+        while len(drive_list) != 0:
+            event = connection.pull_event(wait=True)
+            if event['event'] == 'SHUTDOWN':
+                print("The guest was SHUT DOWN", file=sys.stderr)
+                sys.exit(1)
+
+            if event['event'] == 'BLOCK_JOB_COMPLETED':
+                if event['data']['device'] in drive_list and \
+                        event['data']['type'] == 'backup':
+                        print("*" + event['data']['device'])
+                        drive_list.remove(event['data']['device'])
+
+            if event['event'] == 'BLOCK_JOB_ERROR':
+                if event['data']['device'] in drive_list and \
+                        event['data']['type'] == 'backup':
+                        print(event['data']['device'] + " Backup Failed",
+                              file=sys.stderr)
+                        drive_list.remove(event['data']['device'])
+        print("Backup Complete")
+
+    def _drive_add(self, drive_id, guest_name, target=None):
+        """
+        Adds drive for backup
+        """
+        if target is None:
+            target = os.path.abspath(drive_id)
+
+        if os.path.isdir(os.path.dirname(target)) is False:
+            print("Cannot find target directory", file=sys.stderr)
+            sys.exit(1)
+
+        if guest_name not in self.config.sections():
+            print("Cannot find specified guest", file=sys.stderr)
+            sys.exit(1)
+
+        if "drive_" + drive_id in self.config[guest_name]:
+            print("Drive already marked for backup", file=sys.stderr)
+            sys.exit(1)
+
+        self.verify_guest_running(guest_name)
+
+        connection = QEMUMonitorProtocol(
+                                         self.get_socket_address(
+                                             self.config[guest_name]['qmp']))
+        connection.connect()
+        cmd = {'execute': 'query-block'}
+        returned_json = connection.cmd_obj(cmd)
+        device_present = False
+        for device in returned_json['return']:
+            if device['device'] == drive_id:
+                device_present = True
+                break
+
+        if not device_present:
+            print("No such drive in guest", file=sys.stderr)
+            sys.exit(1)
+
+        drive_id = "drive_" + drive_id
+        for d_id in self.config[guest_name]:
+            if self.config[guest_name][d_id] == target:
+                print("Please choose different target", file=sys.stderr)
+                sys.exit(1)
+        self.config.set(guest_name, drive_id, target)
+        self.write_config()
+        print("Successfully Added Drive")
+
+    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_address(
+                                             socket_address))
+            connection.connect()
+        except socket_error:
+            if socket_error.errno != errno.ECONNREFUSED:
+                print("Connection to guest refused", file=sys.stderr)
+                sys.exit(1)
+
+    def _guest_add(self, guest_name, socket_address):
+        """
+        Adds a guest to the config file
+        """
+        if guest_name in self.config.sections():
+            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):
+        """
+        Removes a guest from config file
+        """
+        if guest_name not in self.config.sections():
+            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)
+            sys.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:")
+        print("Shut down guest")
+        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("Replace " + 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.
+        """
+        guest_name = args.guest
+        self._guest_remove(guest_name)
+        self.write_config()
+
+    def list(self, args):
+        """
+        Prints guests present in Config file
+        """
+        for guest_name in self.config.sections():
+            print(guest_name)
+
+    def guest_add_wrapper(self, args):
+        """
+        Wrapper for _quest_add method
+        """
+        self._guest_add(args.guest, args.qmp)
+
+    def drive_add_wrapper(self, args):
+        """
+        Wrapper for _drive_add method
+        """
+        self._drive_add(args.id, args.guest, args.target)
+
+    def fullbackup_wrapper(self, args):
+        """
+        Wrapper for _full_backup method
+        """
+        self._full_backup(args.guest)
+
+    def restore_wrapper(self, args):
+        """
+        Wrapper for restore
+        """
+        self._restore(args.guest)
+
+
+def main():
+    backup_tool = BackupTool()
+    parser = ArgumentParser()
+    subparsers = parser.add_subparsers(title='Subcommands',
+                                       description='Valid Subcommands',
+                                       help='Subcommand help')
+    guest_parser = subparsers.add_parser('guest', help='Adds or \
+                                                   removes and lists guest(s)')
+    guest_subparsers = guest_parser.add_subparsers(title='Guest Subparser')
+    guest_list_parser = guest_subparsers.add_parser('list',
+                                                    help='Lists all guests')
+    guest_list_parser.set_defaults(func=backup_tool.list)
+
+    guest_add_parser = guest_subparsers.add_parser('add', help='Adds a guest')
+    guest_add_parser.add_argument('--guest', action='store', type=str,
+                                  help='Name of the guest')
+    guest_add_parser.add_argument('--qmp', action='store', type=str,
+                                  help='Path of socket')
+    guest_add_parser.set_defaults(func=backup_tool.guest_add_wrapper)
+
+    guest_remove_parser = guest_subparsers.add_parser('remove',
+                                                      help='removes a guest')
+    guest_remove_parser.add_argument('--guest', action='store', type=str,
+                                     help='Name of the guest')
+    guest_remove_parser.set_defaults(func=backup_tool.guest_remove_wrapper)
+
+    drive_parser = subparsers.add_parser('drive',
+                                         help='Adds drive(s) for backup')
+    drive_subparsers = drive_parser.add_subparsers(title='Add subparser',
+                                                   description='Drive \
+                                                                subparser')
+    drive_add_parser = drive_subparsers.add_parser('add',
+                                                   help='Adds new \
+                                                         drive for backup')
+    drive_add_parser.add_argument('--guest', action='store',
+                                  type=str, help='Name of the guest')
+    drive_add_parser.add_argument('--id', action='store',
+                                  type=str, help='Drive ID')
+    drive_add_parser.add_argument('--target', nargs='?',
+                                  default=None, help='Destination path')
+    drive_add_parser.set_defaults(func=backup_tool.drive_add_wrapper)
+
+    backup_parser = subparsers.add_parser('backup', help='Creates backup')
+    backup_parser.add_argument('--guest', action='store',
+                               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)
+
+if __name__ == '__main__':
+    main()
-- 
2.7.4

[Qemu-devel] [PATCH 2/3] Test for full Backup

[Ishani Chugh]

This patch is the test for full backup implementation in Backup tool.
The test employs two basic substests:
1) Backing up an empty guest and comparing it with base image.
2) Writing a pattern to the guest, creating backup and comparing
   with the base image.


Signed-off-by: Ishani Chugh <chugh.ishani@research.iiit.ac.in>
---
 tests/qemu-iotests/191     | 86 ++++++++++++++++++++++++++++++++++++++++++++++
 tests/qemu-iotests/191.out | 35 +++++++++++++++++++
 tests/qemu-iotests/group   |  2 ++
 3 files changed, 123 insertions(+)
 create mode 100755 tests/qemu-iotests/191
 create mode 100644 tests/qemu-iotests/191.out

diff --git a/tests/qemu-iotests/191 b/tests/qemu-iotests/191
new file mode 100755
index 0000000..16988d8
--- /dev/null
+++ b/tests/qemu-iotests/191
@@ -0,0 +1,86 @@
+#!/bin/bash
+#
+# Test full backup functionality of qemu-backup tool
+#
+# Copyright (C) 2017 Ishani Chugh <chugh.ishani@research.iiit.ac.in>
+#
+# 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/>.
+#
+
+# creator
+owner=chugh.ishani@research.iiit.ac.in
+
+seq=`basename $0`
+echo "QA output created by $seq"
+
+here=`pwd`
+status=1	# failure is the default!
+
+
+# get standard environment, filters and checks
+. ./common.rc
+. ./common.filter
+. ./common.qemu
+
+_supported_fmt generic
+_supported_proto generic
+_supported_os Linux
+
+_cleanup()
+{
+        rm -f "$TEST_DIR"/virtio0
+        rm -f "$CONFIG_FILE"
+}
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+CONFIG_FILE="$TEST_DIR"/backup-config
+SOCKET=unix:"$TEST_DIR"/backup_socket
+size=128M
+
+_make_test_img "$size"
+export QEMU_BACKUP_CONFIG="$CONFIG_FILE"
+qemu_comm_method="monitor"
+echo
+_launch_qemu -drive if=virtio,file="$TEST_IMG" -qmp "$SOCKET",server,nowait
+$PYTHON ../../contrib/backup/qemu-backup.py guest add --guest adad --qmp "$SOCKET"
+$PYTHON ../../contrib/backup/qemu-backup.py drive add --id virtio0 --guest adad --target "$TEST_DIR"/virtio0
+echo
+echo "== Creating backup =="
+$PYTHON ../../contrib/backup/qemu-backup.py backup --guest adad
+_send_qemu_cmd $QEMU_HANDLE 'quit' ''
+wait=1 _cleanup_qemu
+echo
+echo "== Comparing images =="
+$QEMU_IMG compare "$TEST_DIR"/virtio0 "$TEST_IMG"
+_cleanup
+
+_launch_qemu -drive if=virtio,id=virtio0,file="$TEST_IMG" -qmp "$SOCKET",server,nowait
+$PYTHON ../../contrib/backup/qemu-backup.py guest add --guest adad --qmp "$SOCKET"
+$PYTHON ../../contrib/backup/qemu-backup.py drive add --id virtio0 --guest adad --target "$TEST_DIR"/virtio0
+echo
+echo "== Writing Pattern =="
+_send_qemu_cmd $QEMU_HANDLE 'qemu-io virtio0 "write -P 0x22 0 1M"' "(qemu)" | _filter_qemu_io
+echo
+echo "== Creating backup =="
+$PYTHON ../../contrib/backup/qemu-backup.py backup --guest adad
+_send_qemu_cmd $QEMU_HANDLE 'quit' ''
+wait=1 _cleanup_qemu
+echo
+echo "== Comparing images =="
+$QEMU_IMG compare "$TEST_DIR"/virtio0 "$TEST_IMG"
+_cleanup
+_cleanup_test_img
+
+echo "*** done"
+status=0
\ No newline at end of file
diff --git a/tests/qemu-iotests/191.out b/tests/qemu-iotests/191.out
new file mode 100644
index 0000000..c60d47a
--- /dev/null
+++ b/tests/qemu-iotests/191.out
@@ -0,0 +1,35 @@
+QA output created by 191
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728
+
+Successfully Added Guest
+Successfully Added Drive
+
+== Creating backup ==
+Backup Started
+*virtio0
+Backup Complete
+QEMU X.Y.Z monitor - type 'help' for more information
+(qemu) Formatting 'TEST_DIR/virtio0', fmt=qcow2 size=134217728 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+quit
+
+== Comparing images ==
+Images are identical.
+Successfully Added Guest
+Successfully Added Drive
+
+== Writing Pattern ==
+QEMU X.Y.Z monitor - type 'help' for more information
+(qemu) qemu-io virtio0 "write -P 0x22 0 1M"
+
+== Creating backup ==
+Backup Started
+*virtio0
+Backup Complete
+wrote 1048576/1048576 bytes at offset 0
+1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+(qemu) Formatting 'TEST_DIR/virtio0', fmt=qcow2 size=134217728 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+quit
+
+== Comparing images ==
+Images are identical.
+*** done
diff --git a/tests/qemu-iotests/group b/tests/qemu-iotests/group
index afbdc42..66fa231 100644
--- a/tests/qemu-iotests/group
+++ b/tests/qemu-iotests/group
@@ -186,4 +186,6 @@
 188 rw auto quick
 189 rw auto
 190 rw auto quick
+191 rw auto
 192 rw auto quick
+193 rw auto
-- 
2.7.4

[Qemu-devel] [PATCH 3/3] Add manpage for QEMU Backup Tool

[Ishani Chugh]

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 following commit is an
initial implementation of manpage listing the commands which the 
backup tool will support. The manpage wil be build along with other
docs when configure is provided with --enable-docs flag in the 
location contrib/backup in build directory.


Signed-off-by: Ishani Chugh <chugh.ishani@research.iiit.ac.in>
---
 Makefile                        |  14 ++--
 contrib/backup/qemu-backup.texi | 144 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 154 insertions(+), 4 deletions(-)
 create mode 100644 contrib/backup/qemu-backup.texi

diff --git a/Makefile b/Makefile
index 81447b1..ba1574d 100644
--- a/Makefile
+++ b/Makefile
@@ -209,6 +209,7 @@ ifdef BUILD_DOCS
 DOCS=qemu-doc.html qemu-doc.txt qemu.1 qemu-img.1 qemu-nbd.8 qemu-ga.8
 DOCS+=docs/interop/qemu-qmp-ref.html docs/interop/qemu-qmp-ref.txt docs/interop/qemu-qmp-ref.7
 DOCS+=docs/interop/qemu-ga-ref.html docs/interop/qemu-ga-ref.txt docs/interop/qemu-ga-ref.7
+DOCS+=contrib/backup/qemu-backup.html contrib/backup/qemu-backup.txt
 ifdef CONFIG_VIRTFS
 DOCS+=fsdev/virtfs-proxy-helper.1
 endif
@@ -508,6 +509,8 @@ VERSION ?= $(shell cat VERSION)
 
 dist: qemu-$(VERSION).tar.bz2
 
+qemu-backup.8: contrib/backup/qemu-backup.texi
+
 qemu-%.tar.bz2:
 	$(SRC_PATH)/scripts/make-release "$(SRC_PATH)" "$(patsubst qemu-%.tar.bz2,%,$@)"
 
@@ -719,16 +722,19 @@ fsdev/virtfs-proxy-helper.1: fsdev/virtfs-proxy-helper.texi
 qemu-nbd.8: qemu-nbd.texi qemu-option-trace.texi
 qemu-ga.8: qemu-ga.texi
 
-html: qemu-doc.html docs/interop/qemu-qmp-ref.html docs/interop/qemu-ga-ref.html
-info: qemu-doc.info docs/interop/qemu-qmp-ref.info docs/interop/qemu-ga-ref.info
-pdf: qemu-doc.pdf docs/interop/qemu-qmp-ref.pdf docs/interop/qemu-ga-ref.pdf
-txt: qemu-doc.txt docs/interop/qemu-qmp-ref.txt docs/interop/qemu-ga-ref.txt
+html: qemu-doc.html docs/interop/qemu-qmp-ref.html docs/interop/qemu-ga-ref.html contrib/backup/qemu-backup.html
+info: qemu-doc.info docs/interop/qemu-qmp-ref.info docs/interop/qemu-ga-ref.info contrib/backup/qemu-backup.info
+pdf: qemu-doc.pdf docs/interop/qemu-qmp-ref.pdf docs/interop/qemu-ga-ref.pdf contrib/backup/qemu-backup.pdf
+txt: qemu-doc.txt docs/interop/qemu-qmp-ref.txt docs/interop/qemu-ga-ref.txt contrib/backup/qemu-backup.txt
 
 qemu-doc.html qemu-doc.info qemu-doc.pdf qemu-doc.txt: \
 	qemu-img.texi qemu-nbd.texi qemu-options.texi qemu-option-trace.texi \
 	qemu-monitor.texi qemu-img-cmds.texi qemu-ga.texi \
 	qemu-monitor-info.texi
 
+contrib/backup/qemu-backup.html contrib/backup/qemu-backup.pdf contrib/backup/qemu-backup.txt contrib/backup/qemu-backup.info: \
+	contrib/backup/qemu-backup.texi
+
 docs/interop/qemu-ga-ref.dvi docs/interop/qemu-ga-ref.html \
     docs/interop/qemu-ga-ref.info docs/interop/qemu-ga-ref.pdf \
     docs/interop/qemu-ga-ref.txt docs/interop/qemu-ga-ref.7: \
diff --git a/contrib/backup/qemu-backup.texi b/contrib/backup/qemu-backup.texi
new file mode 100644
index 0000000..68e7231
--- /dev/null
+++ b/contrib/backup/qemu-backup.texi
@@ -0,0 +1,144 @@
+\input texinfo
+@setfilename qemu-backup
+
+@documentlanguage en
+@documentencoding UTF-8
+
+@settitle QEMU Backup Tool
+@copying
+
+Copyright @copyright{} 2017 The QEMU Project developers
+@end copying
+@ifinfo
+@direntry
+* QEMU: (QEMU-backup).    Man page for QEMU Backup Tool.
+@end direntry
+@end ifinfo
+@iftex
+@titlepage
+@sp 7
+@center @titlefont{QEMU Backup Tool}
+@sp 1
+@sp 3
+@end titlepage
+@end iftex
+@ifnottex
+@node Top
+@top Short Sample
+
+@menu
+* Name::
+* Synopsis::
+* List of Commands::
+* Command Parameters::
+* Command Descriptions::
+* License::
+@end menu
+
+@end ifnottex
+
+@node Name
+@chapter Name
+
+QEMU disk backup tool.
+
+@node Synopsis
+@chapter Synopsis
+
+qemu-backup command [command options].
+
+@node  List of Commands
+@chapter  List of Commands
+@itemize
+@item qemu-backup guest add --guest guestname --qmp socketpath
+@item qemu-backup guest list
+@item qemu-backup drive add --id driveid --guest guestname --target target
+@item qemu-backup drive add --all --guest guestname --target target
+@item qemu-backup drive list --guest guestname
+@item qemu-backup backup [--inc] --guest guestname
+@item qemu-backup restore --guest guestname
+@item qemu-backup guest remove --guest guestname
+@item qemu-backup drive remove --guest guestname --id driveid
+@end itemize
+@node  Command Parameters
+@chapter  Command Parameters
+@itemize
+@item --all: Add all the drives present in a guest which are suitable for backup.
+@item --guest: Name of the guest.
+@item --id: id of guest or drive.
+@item --inc: (Optional) For incremental backup.
+@item --qmp: Path of qmp socket.
+@item --target: Destination path on which you want your backup to be made.
+@end itemize
+
+@node  Command Descriptions
+@chapter  Command Descriptions
+@itemize
+@item qemu-backup guest add --guest guestname --qmp socketpath
+This command adds a guest to the configuration file given its path to qmp socket.
+
+example:
+qemu-backup guest add --id=fedora --qmp=unix:/var/run/qemu/fedora.sock
+
+qemu-backup guest add --id=fedora --qmp=tcp:localhost:4444
+
+@item qemu-backup guest list
+This commands lists the names of guests which are added to configuration file.
+
+@item qemu-backup drive add --guest guestname --id driveid --target target
+This command adds different drives for backup in a particular guest by giving the name of drive to be backed up and target imagefile in which we want to store the drive backup.
+
+example: qemu-backup drive add --guest=fedora --id=root --target=/backup/root.img
+
+@item qemu-backup drive add --all --guest guestname --destination destination
+This command adds all the drives of the guest for backup other than CDROM drive and read-only drives. Here all the backup drives will have the same names as original drives and target will be the destination folder.
+
+example: qemu-backup drive add --all --guest fedora --destination =/backup/fedora/
+
+@item qemu-backup drive list --guest guestname
+This commands gives the names of the drive present in a guest which are added for backup.
+
+example: qemu-backup drive list --guest=fedora
+
+@item qemu-backup backup --guest guestname
+
+This command makes the backup of the drives, in their respective given destinations. The ids of drive and their destinations are taken from the configuration file.
+
+example: qemu-backup backup --guest=fedora
+
+@item qemu-backup restore --guest guestname
+This command is needed if we want to restore the backup. It will list the commands to be run for performing the same but will not perform any action.
+
+example: qemu-backup restore --guest=fedora
+
+@item qemu-backup guest remove --guest guestname
+This command removes the guest from the configuration file.
+
+example: qemu-backup guest remove --guest=fedora
+
+@item qemu-backup drive remove --guest guestname --id driveid
+This command helps remove a drive which is set for backup in configuration of given host.
+
+example: drive remove --guest=fedora --id=root
+
+@item A full backup can be performed by following the given steps:
+
+Perform a full backup of 'vm001', which has one drive:
+
+qemu-backup guest add --guest vm001 --qmp /path/to/vm001.sock
+
+qemu-backup add --id drive0 --guest vm001 --target /backups/vm001-drive0.img
+
+qemu-backup backup --guest vm001
+
+
+@end itemize
+
+@node License
+@appendix License
+QEMU is a trademark of Fabrice Bellard.
+QEMU is released under the
+@url{https://www.gnu.org/licenses/gpl-2.0.txt,GNU General Public License},
+version 2. Parts of QEMU have specific licenses, see file
+@url{http://git.qemu.org/?p=qemu.git;a=blob_plain;f=LICENSE,LICENSE}.
+@bye
-- 
2.7.4

Re: [Qemu-devel] [PATCH v? 0/3] QEMU Backup Tool

[Eric Blake]

[-- Attachment #1: Type: text/plain, Size: 1002 bytes --]

On 08/29/2017 10:50 AM, Ishani Chugh wrote:
> This patch series is intended to introduce QEMU Backup tool.
> 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.
> This patch series contains three patches,
>                1) QEMU Backup command line tool.
>                2) Test for full backup.
>                3) Manpage for the tool.
> 
> Ishani Chugh (3):
>   backup: QEMU Backup Tool
>   Test for full Backup
>   Add manpage for QEMU Backup Tool

So, which version is this series up to?  We REALLY need the vNNN
designator in the subject line, so that we aren't wasting review time on
a stale version of the series that you have now sent multiple times.

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 619 bytes --]

[Qemu-devel] [PATCH 0/3] QEMU Backup Tool

[Ishani Chugh]

This patch series is intended to introduce QEMU Backup tool.
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.
This patch series contains three patches,
               1) QEMU Backup command line tool.
               2) Test for full backup.
               3) Manpage for the tool.

Ishani Chugh (3):
  backup: QEMU Backup Tool
  Test for full Backup
  Add manpage for QEMU Backup Tool

 Makefile                        |  14 +-
 contrib/backup/qemu-backup.py   | 339 ++++++++++++++++++++++++++++++++++++++++
 contrib/backup/qemu-backup.texi | 144 +++++++++++++++++
 tests/qemu-iotests/191          |  86 ++++++++++
 tests/qemu-iotests/191.out      |  35 +++++
 tests/qemu-iotests/group        |   2 +
 6 files changed, 616 insertions(+), 4 deletions(-)
 create mode 100644 contrib/backup/qemu-backup.py
 create mode 100644 contrib/backup/qemu-backup.texi
 create mode 100755 tests/qemu-iotests/191
 create mode 100644 tests/qemu-iotests/191.out

-- 
2.7.4

[Qemu-devel] [PATCH 1/3] backup: QEMU Backup Tool

[Ishani Chugh]

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.ishani@research.iiit.ac.in>
---
 contrib/backup/qemu-backup.py | 339 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 339 insertions(+)
 create mode 100644 contrib/backup/qemu-backup.py

diff --git a/contrib/backup/qemu-backup.py b/contrib/backup/qemu-backup.py
new file mode 100644
index 0000000..8c17486
--- /dev/null
+++ b/contrib/backup/qemu-backup.py
@@ -0,0 +1,339 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+#
+# Copyright (C) 2017 Ishani Chugh <chugh.ishani@research.iiit.ac.in>
+#
+# 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
+try:
+    import configparser
+except ImportError:
+    import ConfigParser as configparser
+import sys
+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=os.path.expanduser('~') +
+                 '/.config/qemu/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.dirname(self.config_file)):
+                    os.makedirs(os.path.dirname(self.config_file))
+            except:
+                print("Cannot create config directory", file=sys.stderr)
+                sys.exit(1)
+        self.config = configparser.ConfigParser()
+        self.config.read(self.config_file)
+
+    def write_config(self):
+        """
+        Writes configuration to ini 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_address(self, socket_address):
+        """
+        Return Socket address in form of string or tuple
+        """
+        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):
+        """
+        Performs full backup of guest
+        """
+        if guest_name not in self.config.sections():
+            print("Cannot find specified guest", file=sys.stderr)
+            sys.exit(1)
+
+        self.verify_guest_running(guest_name)
+        connection = QEMUMonitorProtocol(
+                                         self.get_socket_address(
+                                             self.config[guest_name]['qmp']))
+        connection.connect()
+        cmd = {"execute": "transaction", "arguments": {"actions": []}}
+        drive_list = []
+        for key in self.config[guest_name]:
+            if key.startswith("drive_"):
+                drive = key[len('drive_'):]
+                drive_list.append(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)
+        qmp_return = connection.cmd_obj(cmd)
+        if 'error' in qmp_return:
+            print(qmp_return['error']['desc'], file=sys.stderr)
+            sys.exit(1)
+        print("Backup Started")
+        while len(drive_list) != 0:
+            event = connection.pull_event(wait=True)
+            if event['event'] == 'SHUTDOWN':
+                print("The guest was SHUT DOWN", file=sys.stderr)
+                sys.exit(1)
+
+            if event['event'] == 'RESET':
+                print("The guest was Rebooted", file=sys.stderr)
+                sys.exit(1)
+
+            if event['event'] == 'BLOCK_JOB_COMPLETED':
+                if event['data']['device'] in drive_list and \
+                        event['data']['type'] == 'backup':
+                        print("*" + event['data']['device'])
+                        drive_list.remove(event['data']['device'])
+
+            if event['event'] == 'BLOCK_JOB_ERROR':
+                if event['data']['device'] in drive_list and \
+                        event['data']['type'] == 'backup':
+                        print(event['data']['device'] + " Backup Failed",
+                              file=sys.stderr)
+                        drive_list.remove(event['data']['device'])
+        print("Backup Complete")
+
+    def _drive_add(self, drive_id, guest_name, target=None):
+        """
+        Adds drive for backup
+        """
+        if target is None:
+            target = os.path.abspath(drive_id)
+
+        if os.path.isdir(os.path.dirname(target)) is False:
+            print("Cannot find target directory", file=sys.stderr)
+            sys.exit(1)
+
+        if guest_name not in self.config.sections():
+            print("Cannot find specified guest", file=sys.stderr)
+            sys.exit(1)
+
+        if "drive_" + drive_id in self.config[guest_name]:
+            print("Drive already marked for backup", file=sys.stderr)
+            sys.exit(1)
+
+        self.verify_guest_running(guest_name)
+
+        connection = QEMUMonitorProtocol(
+                                         self.get_socket_address(
+                                             self.config[guest_name]['qmp']))
+        connection.connect()
+        cmd = {'execute': 'query-block'}
+        returned_json = connection.cmd_obj(cmd)
+        device_present = False
+        for device in returned_json['return']:
+            if device['device'] == drive_id:
+                device_present = True
+                break
+
+        if not device_present:
+            print("No such drive in guest", file=sys.stderr)
+            sys.exit(1)
+
+        drive_id = "drive_" + drive_id
+        for d_id in self.config[guest_name]:
+            if self.config[guest_name][d_id] == target:
+                print("Please choose different target", file=sys.stderr)
+                sys.exit(1)
+        self.config.set(guest_name, drive_id, target)
+        self.write_config()
+        print("Successfully Added Drive")
+
+    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_address(
+                                             socket_address))
+            connection.connect()
+        except socket_error:
+            if socket_error.errno != errno.ECONNREFUSED:
+                print("Connection to guest refused", file=sys.stderr)
+                sys.exit(1)
+
+    def _guest_add(self, guest_name, socket_address):
+        """
+        Adds a guest to the config file
+        """
+        if guest_name in self.config.sections():
+            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):
+        """
+        Removes a guest from config file
+        """
+        if guest_name not in self.config.sections():
+            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)
+            sys.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:")
+        print("Shut down guest")
+        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("Replace " + 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.
+        """
+        guest_name = args.guest
+        self._guest_remove(guest_name)
+        self.write_config()
+
+    def list(self, args):
+        """
+        Prints guests present in Config file
+        """
+        for guest_name in self.config.sections():
+            print(guest_name)
+
+    def guest_add_wrapper(self, args):
+        """
+        Wrapper for _quest_add method
+        """
+        self._guest_add(args.guest, args.qmp)
+
+    def drive_add_wrapper(self, args):
+        """
+        Wrapper for _drive_add method
+        """
+        self._drive_add(args.id, args.guest, args.target)
+
+    def fullbackup_wrapper(self, args):
+        """
+        Wrapper for _full_backup method
+        """
+        self._full_backup(args.guest)
+
+    def restore_wrapper(self, args):
+        """
+        Wrapper for restore
+        """
+        self._restore(args.guest)
+
+
+def main():
+    backup_tool = BackupTool()
+    parser = ArgumentParser()
+    subparsers = parser.add_subparsers(title='Subcommands',
+                                       description='Valid Subcommands',
+                                       help='Subcommand help')
+    guest_parser = subparsers.add_parser('guest', help='Adds or \
+                                                   removes and lists guest(s)')
+    guest_subparsers = guest_parser.add_subparsers(title='Guest Subparser')
+    guest_list_parser = guest_subparsers.add_parser('list',
+                                                    help='Lists all guests')
+    guest_list_parser.set_defaults(func=backup_tool.list)
+
+    guest_add_parser = guest_subparsers.add_parser('add', help='Adds a guest')
+    guest_add_parser.add_argument('--guest', action='store', type=str,
+                                  help='Name of the guest')
+    guest_add_parser.add_argument('--qmp', action='store', type=str,
+                                  help='Path of socket')
+    guest_add_parser.set_defaults(func=backup_tool.guest_add_wrapper)
+
+    guest_remove_parser = guest_subparsers.add_parser('remove',
+                                                      help='removes a guest')
+    guest_remove_parser.add_argument('--guest', action='store', type=str,
+                                     help='Name of the guest')
+    guest_remove_parser.set_defaults(func=backup_tool.guest_remove_wrapper)
+
+    drive_parser = subparsers.add_parser('drive',
+                                         help='Adds drive(s) for backup')
+    drive_subparsers = drive_parser.add_subparsers(title='Add subparser',
+                                                   description='Drive \
+                                                                subparser')
+    drive_add_parser = drive_subparsers.add_parser('add',
+                                                   help='Adds new \
+                                                         drive for backup')
+    drive_add_parser.add_argument('--guest', action='store',
+                                  type=str, help='Name of the guest')
+    drive_add_parser.add_argument('--id', action='store',
+                                  type=str, help='Drive ID')
+    drive_add_parser.add_argument('--target', nargs='?',
+                                  default=None, help='Destination path')
+    drive_add_parser.set_defaults(func=backup_tool.drive_add_wrapper)
+
+    backup_parser = subparsers.add_parser('backup', help='Creates backup')
+    backup_parser.add_argument('--guest', action='store',
+                               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)
+
+if __name__ == '__main__':
+    main()
-- 
2.7.4

[Qemu-devel] [PATCH 0/3] QEMU Backup Tool

[Ishani Chugh]

This patch series is intended to introduce QEMU Backup tool.
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.
This patch series contains three patches,
               1) QEMU Backup command line tool.
               2) Test for full backup.
               3) Manpage for the tool.

Ishani Chugh (3):
  backup: QEMU Backup Tool
  Test for full Backup
  Add manpage for QEMU Backup Tool

 Makefile                        |  14 +-
 contrib/backup/qemu-backup.py   | 338 ++++++++++++++++++++++++++++++++++++++++
 contrib/backup/qemu-backup.texi | 144 +++++++++++++++++
 tests/qemu-iotests/191          |  78 ++++++++++
 tests/qemu-iotests/191.out      |  33 ++++
 tests/qemu-iotests/group        |   1 +
 6 files changed, 604 insertions(+), 4 deletions(-)
 create mode 100644 contrib/backup/qemu-backup.py
 create mode 100644 contrib/backup/qemu-backup.texi
 create mode 100755 tests/qemu-iotests/191
 create mode 100644 tests/qemu-iotests/191.out

-- 
2.7.4

[Qemu-devel] [PATCH 1/3] backup: QEMU Backup Tool

[Ishani Chugh]

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.ishani@research.iiit.ac.in>
---
 contrib/backup/qemu-backup.py | 338 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 338 insertions(+)
 create mode 100644 contrib/backup/qemu-backup.py

diff --git a/contrib/backup/qemu-backup.py b/contrib/backup/qemu-backup.py
new file mode 100644
index 0000000..b4a9efd
--- /dev/null
+++ b/contrib/backup/qemu-backup.py
@@ -0,0 +1,338 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+#
+# Copyright (C) 2017 Ishani Chugh <chugh.ishani@research.iiit.ac.in>
+#
+# 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
+try:
+    import configparser
+except ImportError:
+    import ConfigParser as configparser
+import sys
+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=os.path.expanduser('~') +
+                 '/.config/qemu/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.dirname(self.config_file)):
+                    os.makedirs(os.path.dirname(self.config_file))
+            except:
+                print("Cannot create config directory", file=sys.stderr)
+                sys.exit(1)
+        self.config = configparser.ConfigParser()
+        self.config.read(self.config_file)
+
+    def write_config(self):
+        """
+        Writes configuration to ini 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_address(self, socket_address):
+        """
+        Return Socket address in form of string or tuple
+        """
+        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):
+        """
+        Performs full backup of guest
+        """
+        if guest_name not in self.config.sections():
+            print("Cannot find specified guest", file=sys.stderr)
+            sys.exit(1)
+
+        self.verify_guest_running(guest_name)
+        connection = QEMUMonitorProtocol(
+                                         self.get_socket_address(
+                                             self.config[guest_name]['qmp']))
+        connection.connect()
+        cmd = {"execute": "transaction", "arguments": {"actions": []}}
+        drive_list = []
+        for key in self.config[guest_name]:
+            if key.startswith("drive_"):
+                drive = key[len('drive_'):]
+                drive_list.append(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)
+        qmp_return = connection.cmd_obj(cmd)
+        if 'error' in qmp_return:
+            print(qmp_return['error']['desc'], file=sys.stderr)
+            sys.exit(1)
+        print("Backup Started")
+        while len(drive_list) != 0:
+            event = connection.pull_event(wait=True)
+            print(event)
+            if event['event'] == 'SHUTDOWN':
+                print("The guest was SHUT DOWN", file=sys.stderr)
+                sys.exit(1)
+
+            if event['event'] == 'RESET':
+                print("The guest was Rebooted", file=sys.stderr)
+                sys.exit(1)
+
+            if event['event'] == 'BLOCK_JOB_COMPLETED':
+                if event['data']['device'] in drive_list and \
+                        event['data']['type'] == 'backup':
+                        print("*"+event['data']['device'])
+                        drive_list.remove(event['data']['device'])
+
+            if event['event'] == 'BLOCK_JOB_ERROR':
+                if event['data']['device'] in drive_list and \
+                        event['data']['type'] == 'backup':
+                        print(event['data']['device']+" Backup Failed", file=sys.stderr)
+        print("Backup Complete")
+
+    def _drive_add(self, drive_id, guest_name, target=None):
+        """
+        Adds drive for backup
+        """
+        if target is None:
+            target = os.path.abspath(drive_id)
+
+        if os.path.isdir(os.path.dirname(target)) is False:
+            print("Cannot find target directory", file=sys.stderr)
+            sys.exit(1)
+
+        if guest_name not in self.config.sections():
+            print("Cannot find specified guest", file=sys.stderr)
+            sys.exit(1)
+
+        if "drive_"+drive_id in self.config[guest_name]:
+            print("Drive already marked for backup", file=sys.stderr)
+            sys.exit(1)
+
+        self.verify_guest_running(guest_name)
+
+        connection = QEMUMonitorProtocol(
+                                         self.get_socket_address(
+                                             self.config[guest_name]['qmp']))
+        connection.connect()
+        cmd = {'execute': 'query-block'}
+        returned_json = connection.cmd_obj(cmd)
+        device_present = False
+        for device in returned_json['return']:
+            if device['device'] == drive_id:
+                device_present = True
+                break
+
+        if not device_present:
+            print("No such drive in guest", file=sys.stderr)
+            sys.exit(1)
+
+        drive_id = "drive_" + drive_id
+        for d_id in self.config[guest_name]:
+            if self.config[guest_name][d_id] == target:
+                print("Please choose different target", file=sys.stderr)
+                sys.exit(1)
+        self.config.set(guest_name, drive_id, target)
+        self.write_config()
+        print("Successfully Added Drive")
+
+    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_address(
+                                             socket_address))
+            connection.connect()
+        except socket_error:
+            if socket_error.errno != errno.ECONNREFUSED:
+                print("Connection to guest refused", file=sys.stderr)
+                sys.exit(1)
+
+    def _guest_add(self, guest_name, socket_address):
+        """
+        Adds a guest to the config file
+        """
+        if guest_name in self.config.sections():
+            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):
+        """
+        Removes a guest from config file
+        """
+        if guest_name not in self.config.sections():
+            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)
+            sys.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:")
+        print("Shut down guest")
+        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("Replace "+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.
+        """
+        guest_name = args.guest
+        self._guest_remove(guest_name)
+        self.write_config()
+
+    def list(self, args):
+        """
+        Prints guests present in Config file
+        """
+        for guest_name in self.config.sections():
+            print(guest_name)
+
+    def guest_add_wrapper(self, args):
+        """
+        Wrapper for _quest_add method
+        """
+        self._guest_add(args.guest, args.qmp)
+
+    def drive_add_wrapper(self, args):
+        """
+        Wrapper for _drive_add method
+        """
+        self._drive_add(args.id, args.guest, args.target)
+
+    def fullbackup_wrapper(self, args):
+        """
+        Wrapper for _full_backup method
+        """
+        self._full_backup(args.guest)
+
+    def restore_wrapper(self, args):
+        """
+        Wrapper for restore
+        """
+        self._restore(args.guest)
+
+
+def main():
+    backup_tool = BackupTool()
+    parser = ArgumentParser()
+    subparsers = parser.add_subparsers(title='Subcommands',
+                                       description='Valid Subcommands',
+                                       help='Subcommand help')
+    guest_parser = subparsers.add_parser('guest', help='Adds or \
+                                                   removes and lists guest(s)')
+    guest_subparsers = guest_parser.add_subparsers(title='Guest Subparser')
+    guest_list_parser = guest_subparsers.add_parser('list',
+                                                    help='Lists all guests')
+    guest_list_parser.set_defaults(func=backup_tool.list)
+
+    guest_add_parser = guest_subparsers.add_parser('add', help='Adds a guest')
+    guest_add_parser.add_argument('--guest', action='store', type=str,
+                                  help='Name of the guest')
+    guest_add_parser.add_argument('--qmp', action='store', type=str,
+                                  help='Path of socket')
+    guest_add_parser.set_defaults(func=backup_tool.guest_add_wrapper)
+
+    guest_remove_parser = guest_subparsers.add_parser('remove',
+                                                      help='removes a guest')
+    guest_remove_parser.add_argument('--guest', action='store', type=str,
+                                     help='Name of the guest')
+    guest_remove_parser.set_defaults(func=backup_tool.guest_remove_wrapper)
+
+    drive_parser = subparsers.add_parser('drive',
+                                         help='Adds drive(s) for backup')
+    drive_subparsers = drive_parser.add_subparsers(title='Add subparser',
+                                                   description='Drive \
+                                                                subparser')
+    drive_add_parser = drive_subparsers.add_parser('add',
+                                                   help='Adds new \
+                                                         drive for backup')
+    drive_add_parser.add_argument('--guest', action='store',
+                                  type=str, help='Name of the guest')
+    drive_add_parser.add_argument('--id', action='store',
+                                  type=str, help='Drive ID')
+    drive_add_parser.add_argument('--target', nargs='?',
+                                  default=None, help='Destination path')
+    drive_add_parser.set_defaults(func=backup_tool.drive_add_wrapper)
+
+    backup_parser = subparsers.add_parser('backup', help='Creates backup')
+    backup_parser.add_argument('--guest', action='store',
+                               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)
+
+if __name__ == '__main__':
+    main()
-- 
2.7.4

Re: [Qemu-devel] [PATCH 1/3] backup: QEMU Backup Tool

[Stefan Hajnoczi]

On Wed, Aug 23, 2017 at 06:34:38PM +0530, Ishani Chugh wrote:
> +    def write_config(self):
> +        """
> +        Writes configuration to ini file.
> +        """
> +        config_file = open(self.config_file+".tmp", 'w')

Please use whitespace around arithmetic operators:

  self.config_file + ".tmp"

> +        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)

self.config_file + ".tmp"

> +
> +    def get_socket_address(self, socket_address):
> +        """
> +        Return Socket address in form of string or tuple
> +        """
> +        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):
> +        """
> +        Performs full backup of guest
> +        """
> +        if guest_name not in self.config.sections():
> +            print("Cannot find specified guest", file=sys.stderr)
> +            sys.exit(1)
> +
> +        self.verify_guest_running(guest_name)
> +        connection = QEMUMonitorProtocol(
> +                                         self.get_socket_address(
> +                                             self.config[guest_name]['qmp']))
> +        connection.connect()
> +        cmd = {"execute": "transaction", "arguments": {"actions": []}}
> +        drive_list = []
> +        for key in self.config[guest_name]:
> +            if key.startswith("drive_"):
> +                drive = key[len('drive_'):]
> +                drive_list.append(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)
> +        qmp_return = connection.cmd_obj(cmd)
> +        if 'error' in qmp_return:
> +            print(qmp_return['error']['desc'], file=sys.stderr)
> +            sys.exit(1)
> +        print("Backup Started")
> +        while len(drive_list) != 0:

PEP8 says:

  For sequences, (strings, lists, tuples), use the fact that empty sequences are false.

  Yes: if not seq:
       if seq:

  No: if len(seq):
      if not len(seq):

This statement should be:

  while drive_list:

> +            event = connection.pull_event(wait=True)
> +            print(event)

Please remove debugging or add a --verbose command-line option that
makes the print statement conditional:

  if verbose:
      print(event)

> +            if event['event'] == 'SHUTDOWN':
> +                print("The guest was SHUT DOWN", file=sys.stderr)
> +                sys.exit(1)
> +
> +            if event['event'] == 'RESET':
> +                print("The guest was Rebooted", file=sys.stderr)
> +                sys.exit(1)

I think you found this is a soft reset and the blockjob is still
running.  There is no need to exit.  You can ignore this event.

> +
> +            if event['event'] == 'BLOCK_JOB_COMPLETED':
> +                if event['data']['device'] in drive_list and \
> +                        event['data']['type'] == 'backup':
> +                        print("*"+event['data']['device'])

Please use whitespace around arithmetic operators:

  print("*" + event['data']['device'])

> +                        drive_list.remove(event['data']['device'])
> +
> +            if event['event'] == 'BLOCK_JOB_ERROR':
> +                if event['data']['device'] in drive_list and \
> +                        event['data']['type'] == 'backup':
> +                        print(event['data']['device']+" Backup Failed", file=sys.stderr)

The drive was not removed from drive_list so the loop never terminates.

sys.exit(1)?

[Qemu-devel] [PATCH 0/3] QEMU Backup Tool

[Ishani Chugh]

This patch series is intended to introduce QEMU Backup tool.
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.
This patch series contains three patches,
	       1) QEMU Backup command line tool.
	       2) Test for full backup.
	       3) Manpage for the tool.

Ishani Chugh (3):
  backup: QEMU Backup Tool
  Test for full Backup
  Add manpage for QEMU Backup Tool

 Makefile                        |  14 +-
 contrib/backup/qemu-backup.py   | 334 ++++++++++++++++++++++++++++++++++++++++
 contrib/backup/qemu-backup.texi | 134 ++++++++++++++++
 tests/qemu-iotests/191          |  78 ++++++++++
 tests/qemu-iotests/191.out      |  33 ++++
 tests/qemu-iotests/group        |   1 +
 6 files changed, 590 insertions(+), 4 deletions(-)
 create mode 100644 contrib/backup/qemu-backup.py
 create mode 100644 contrib/backup/qemu-backup.texi
 create mode 100755 tests/qemu-iotests/191
 create mode 100644 tests/qemu-iotests/191.out

--
2.7.4

[Qemu-devel] [PATCH 1/3] backup: QEMU Backup Tool

[Ishani Chugh]

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.ishani@research.iiit.ac.in>
---
 contrib/backup/qemu-backup.py | 334 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 334 insertions(+)
 create mode 100644 contrib/backup/qemu-backup.py

diff --git a/contrib/backup/qemu-backup.py b/contrib/backup/qemu-backup.py
new file mode 100644
index 0000000..08570f7
--- /dev/null
+++ b/contrib/backup/qemu-backup.py
@@ -0,0 +1,334 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+#
+# Copyright (C) 2017 Ishani Chugh <chugh.ishani@research.iiit.ac.in>
+#
+# 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
+try:
+    import configparser
+except ImportError:
+    import ConfigParser as configparser
+import sys
+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=os.path.expanduser('~') +
+                 '/.config/qemu/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.dirname(self.config_file)):
+                    os.makedirs(os.path.dirname(self.config_file))
+            except:
+                print("Cannot create config directory", file=sys.stderr)
+                sys.exit(1)
+        self.config = configparser.ConfigParser()
+        self.config.read(self.config_file)
+
+    def write_config(self):
+        """
+        Writes configuration to ini 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_address(self, socket_address):
+        """
+        Return Socket address in form of string or tuple
+        """
+        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):
+        """
+        Performs full backup of guest
+        """
+        if guest_name not in self.config.sections():
+            print("Cannot find specified guest", file=sys.stderr)
+            sys.exit(1)
+
+        self.verify_guest_running(guest_name)
+        connection = QEMUMonitorProtocol(
+                                         self.get_socket_address(
+                                             self.config[guest_name]['qmp']))
+        connection.connect()
+        cmd = {"execute": "transaction", "arguments": {"actions": []}}
+        drive_list = []
+        for key in self.config[guest_name]:
+            if key.startswith("drive_"):
+                drive = key[len('drive_'):]
+                drive_list.append(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)
+        qmp_return = connection.cmd_obj(cmd)
+        if 'error' in qmp_return:
+            print(qmp_return['error']['desc'], file=sys.stderr)
+            sys.exit(1)
+        print("Backup Started")
+        while len(drive_list) != 0:
+            event = connection.pull_event(wait=True)
+            if event['event'] == 'SHUTDOWN':
+                print("The guest was SHUT DOWN", file=sys.stderr)
+                sys.exit(1)
+
+            if event['event'] == 'RESET':
+                print("The guest was Rebooted", file=sys.stderr)
+                sys.exit(1)
+
+            if event['data']['device'] in drive_list and \
+                    event['data']['type'] == 'backup':
+                if event['event'] == 'BLOCK_JOB_COMPLETED':
+                    print("*"+event['data']['device'])
+                    drive_list.remove(event['data']['device'])
+                elif event['event'] == 'BLOCK_JOB_ERROR':
+                    print("Cannot Complete Backup", file=sys.stderr)
+                    sys.exit(1)
+        print("Backup Complete")
+
+    def _drive_add(self, drive_id, guest_name, target=None):
+        """
+        Adds drive for backup
+        """
+        if target is None:
+            target = os.path.abspath(drive_id)
+
+        if os.path.isdir(os.path.dirname(target)) is False:
+            print("Cannot find target directory", file=sys.stderr)
+            sys.exit(1)
+
+        if guest_name not in self.config.sections():
+            print("Cannot find specified guest", file=sys.stderr)
+            sys.exit(1)
+
+        if "drive_"+drive_id in self.config[guest_name]:
+            print("Drive already marked for backup", file=sys.stderr)
+            sys.exit(1)
+
+        self.verify_guest_running(guest_name)
+
+        connection = QEMUMonitorProtocol(
+                                         self.get_socket_address(
+                                             self.config[guest_name]['qmp']))
+        connection.connect()
+        cmd = {'execute': 'query-block'}
+        returned_json = connection.cmd_obj(cmd)
+        device_present = False
+        for device in returned_json['return']:
+            if device['device'] == drive_id:
+                device_present = True
+                break
+
+        if not device_present:
+            print("No such drive in guest", file=sys.stderr)
+            sys.exit(1)
+
+        drive_id = "drive_" + drive_id
+        for d_id in self.config[guest_name]:
+            if self.config[guest_name][d_id] == target:
+                print("Please choose different target", file=sys.stderr)
+                sys.exit(1)
+        self.config.set(guest_name, drive_id, target)
+        self.write_config()
+        print("Successfully Added Drive")
+
+    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_address(
+                                             socket_address))
+            connection.connect()
+        except socket_error:
+            if socket_error.errno != errno.ECONNREFUSED:
+                print("Connection to guest refused", file=sys.stderr)
+                sys.exit(1)
+
+    def _guest_add(self, guest_name, socket_address):
+        """
+        Adds a guest to the config file
+        """
+        if guest_name in self.config.sections():
+            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):
+        """
+        Removes a guest from config file
+        """
+        if guest_name not in self.config.sections():
+            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)
+            sys.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.
+        """
+        guest_name = args.guest
+        self._guest_remove(guest_name)
+        self.write_config()
+
+    def list(self, args):
+        """
+        Prints guests present in Config file
+        """
+        for guest_name in self.config.sections():
+            print(guest_name)
+
+    def guest_add_wrapper(self, args):
+        """
+        Wrapper for _quest_add method
+        """
+        self._guest_add(args.guest, args.qmp)
+
+    def drive_add_wrapper(self, args):
+        """
+        Wrapper for _drive_add method
+        """
+        self._drive_add(args.id, args.guest, args.target)
+
+    def fullbackup_wrapper(self, args):
+        """
+        Wrapper for _full_backup method
+        """
+        self._full_backup(args.guest)
+
+    def restore_wrapper(self, args):
+        """
+        Wrapper for restore
+        """
+        self._restore(args.guest)
+
+
+def main():
+    backup_tool = BackupTool()
+    parser = ArgumentParser()
+    subparsers = parser.add_subparsers(title='Subcommands',
+                                       description='Valid Subcommands',
+                                       help='Subcommand help')
+    guest_parser = subparsers.add_parser('guest', help='Adds or \
+                                                   removes and lists guest(s)')
+    guest_subparsers = guest_parser.add_subparsers(title='Guest Subparser')
+    guest_list_parser = guest_subparsers.add_parser('list',
+                                                    help='Lists all guests')
+    guest_list_parser.set_defaults(func=backup_tool.list)
+
+    guest_add_parser = guest_subparsers.add_parser('add', help='Adds a guest')
+    guest_add_parser.add_argument('--guest', action='store', type=str,
+                                  help='Name of the guest')
+    guest_add_parser.add_argument('--qmp', action='store', type=str,
+                                  help='Path of socket')
+    guest_add_parser.set_defaults(func=backup_tool.guest_add_wrapper)
+
+    guest_remove_parser = guest_subparsers.add_parser('remove',
+                                                      help='removes a guest')
+    guest_remove_parser.add_argument('--guest', action='store', type=str,
+                                     help='Name of the guest')
+    guest_remove_parser.set_defaults(func=backup_tool.guest_remove_wrapper)
+
+    drive_parser = subparsers.add_parser('drive',
+                                         help='Adds drive(s) for backup')
+    drive_subparsers = drive_parser.add_subparsers(title='Add subparser',
+                                                   description='Drive \
+                                                                subparser')
+    drive_add_parser = drive_subparsers.add_parser('add',
+                                                   help='Adds new \
+                                                         drive for backup')
+    drive_add_parser.add_argument('--guest', action='store',
+                                  type=str, help='Name of the guest')
+    drive_add_parser.add_argument('--id', action='store',
+                                  type=str, help='Drive ID')
+    drive_add_parser.add_argument('--target', nargs='?',
+                                  default=None, help='Destination path')
+    drive_add_parser.set_defaults(func=backup_tool.drive_add_wrapper)
+
+    backup_parser = subparsers.add_parser('backup', help='Creates backup')
+    backup_parser.add_argument('--guest', action='store',
+                               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)
+
+if __name__ == '__main__':
+    main()
-- 
2.7.4

Re: [Qemu-devel] [PATCH 1/3] backup: QEMU Backup Tool

[Stefan Hajnoczi]

On Mon, Aug 21, 2017 at 04:40:37PM +0530, Ishani Chugh wrote:
> 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.ishani@research.iiit.ac.in>
> ---
>  contrib/backup/qemu-backup.py | 334 ++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 334 insertions(+)
>  create mode 100644 contrib/backup/qemu-backup.py
> 
> diff --git a/contrib/backup/qemu-backup.py b/contrib/backup/qemu-backup.py
> new file mode 100644
> index 0000000..08570f7
> --- /dev/null
> +++ b/contrib/backup/qemu-backup.py
> @@ -0,0 +1,334 @@
> +#!/usr/bin/python
> +# -*- coding: utf-8 -*-
> +#
> +# Copyright (C) 2017 Ishani Chugh <chugh.ishani@research.iiit.ac.in>
> +#
> +# 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
> +try:
> +    import configparser
> +except ImportError:
> +    import ConfigParser as configparser
> +import sys
> +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=os.path.expanduser('~') +
> +                 '/.config/qemu/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.dirname(self.config_file)):
> +                    os.makedirs(os.path.dirname(self.config_file))
> +            except:
> +                print("Cannot create config directory", file=sys.stderr)
> +                sys.exit(1)
> +        self.config = configparser.ConfigParser()
> +        self.config.read(self.config_file)
> +
> +    def write_config(self):
> +        """
> +        Writes configuration to ini 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_address(self, socket_address):
> +        """
> +        Return Socket address in form of string or tuple
> +        """
> +        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):
> +        """
> +        Performs full backup of guest
> +        """
> +        if guest_name not in self.config.sections():
> +            print("Cannot find specified guest", file=sys.stderr)
> +            sys.exit(1)
> +
> +        self.verify_guest_running(guest_name)
> +        connection = QEMUMonitorProtocol(
> +                                         self.get_socket_address(
> +                                             self.config[guest_name]['qmp']))
> +        connection.connect()
> +        cmd = {"execute": "transaction", "arguments": {"actions": []}}
> +        drive_list = []
> +        for key in self.config[guest_name]:
> +            if key.startswith("drive_"):
> +                drive = key[len('drive_'):]
> +                drive_list.append(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)
> +        qmp_return = connection.cmd_obj(cmd)
> +        if 'error' in qmp_return:
> +            print(qmp_return['error']['desc'], file=sys.stderr)
> +            sys.exit(1)
> +        print("Backup Started")
> +        while len(drive_list) != 0:
> +            event = connection.pull_event(wait=True)
> +            if event['event'] == 'SHUTDOWN':
> +                print("The guest was SHUT DOWN", file=sys.stderr)
> +                sys.exit(1)
> +
> +            if event['event'] == 'RESET':
> +                print("The guest was Rebooted", file=sys.stderr)
> +                sys.exit(1)
> +
> +            if event['data']['device'] in drive_list and \
> +                    event['data']['type'] == 'backup':

At this point the event[] dict might be a non-BLOCK_JOB_* event.
Therefore event['data']['device'] will raise a KeyError exception.

You must check event['event'] before assuming it contains certain
fields.

> +                if event['event'] == 'BLOCK_JOB_COMPLETED':
> +                    print("*"+event['data']['device'])
> +                    drive_list.remove(event['data']['device'])
> +                elif event['event'] == 'BLOCK_JOB_ERROR':
> +                    print("Cannot Complete Backup", file=sys.stderr)
> +                    sys.exit(1)
> +        print("Backup Complete")
> +
> +    def _drive_add(self, drive_id, guest_name, target=None):
> +        """
> +        Adds drive for backup
> +        """
> +        if target is None:
> +            target = os.path.abspath(drive_id)
> +
> +        if os.path.isdir(os.path.dirname(target)) is False:
> +            print("Cannot find target directory", file=sys.stderr)
> +            sys.exit(1)
> +
> +        if guest_name not in self.config.sections():
> +            print("Cannot find specified guest", file=sys.stderr)
> +            sys.exit(1)
> +
> +        if "drive_"+drive_id in self.config[guest_name]:
> +            print("Drive already marked for backup", file=sys.stderr)
> +            sys.exit(1)
> +
> +        self.verify_guest_running(guest_name)
> +
> +        connection = QEMUMonitorProtocol(
> +                                         self.get_socket_address(
> +                                             self.config[guest_name]['qmp']))
> +        connection.connect()
> +        cmd = {'execute': 'query-block'}
> +        returned_json = connection.cmd_obj(cmd)
> +        device_present = False
> +        for device in returned_json['return']:
> +            if device['device'] == drive_id:
> +                device_present = True
> +                break
> +
> +        if not device_present:
> +            print("No such drive in guest", file=sys.stderr)
> +            sys.exit(1)
> +
> +        drive_id = "drive_" + drive_id
> +        for d_id in self.config[guest_name]:
> +            if self.config[guest_name][d_id] == target:
> +                print("Please choose different target", file=sys.stderr)
> +                sys.exit(1)
> +        self.config.set(guest_name, drive_id, target)
> +        self.write_config()
> +        print("Successfully Added Drive")
> +
> +    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_address(
> +                                             socket_address))
> +            connection.connect()
> +        except socket_error:
> +            if socket_error.errno != errno.ECONNREFUSED:
> +                print("Connection to guest refused", file=sys.stderr)
> +                sys.exit(1)
> +
> +    def _guest_add(self, guest_name, socket_address):
> +        """
> +        Adds a guest to the config file
> +        """
> +        if guest_name in self.config.sections():
> +            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):
> +        """
> +        Removes a guest from config file
> +        """
> +        if guest_name not in self.config.sections():
> +            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)
> +            sys.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)

I suggest print('Replace ' + location + ' with ' + target) for a
slightly clearer message.

> +
> +                if not device_present:
> +                    print("No such drive in guest", file=sys.stderr)
> +                    sys.exit(1)

Since the command itself requires the guest to be running
users are very likely to manipulate the disk image files while the guest
is running.

This command must prompt the user to shut down the guest before
restoring.

> +
> +    def guest_remove_wrapper(self, args):
> +        """
> +        Wrapper for _guest_remove method.
> +        """
> +        guest_name = args.guest
> +        self._guest_remove(guest_name)
> +        self.write_config()
> +
> +    def list(self, args):
> +        """
> +        Prints guests present in Config file
> +        """
> +        for guest_name in self.config.sections():
> +            print(guest_name)
> +
> +    def guest_add_wrapper(self, args):
> +        """
> +        Wrapper for _quest_add method
> +        """
> +        self._guest_add(args.guest, args.qmp)
> +
> +    def drive_add_wrapper(self, args):
> +        """
> +        Wrapper for _drive_add method
> +        """
> +        self._drive_add(args.id, args.guest, args.target)
> +
> +    def fullbackup_wrapper(self, args):
> +        """
> +        Wrapper for _full_backup method
> +        """
> +        self._full_backup(args.guest)
> +
> +    def restore_wrapper(self, args):
> +        """
> +        Wrapper for restore
> +        """
> +        self._restore(args.guest)
> +
> +
> +def main():
> +    backup_tool = BackupTool()
> +    parser = ArgumentParser()
> +    subparsers = parser.add_subparsers(title='Subcommands',
> +                                       description='Valid Subcommands',
> +                                       help='Subcommand help')
> +    guest_parser = subparsers.add_parser('guest', help='Adds or \
> +                                                   removes and lists guest(s)')
> +    guest_subparsers = guest_parser.add_subparsers(title='Guest Subparser')
> +    guest_list_parser = guest_subparsers.add_parser('list',
> +                                                    help='Lists all guests')
> +    guest_list_parser.set_defaults(func=backup_tool.list)
> +
> +    guest_add_parser = guest_subparsers.add_parser('add', help='Adds a guest')
> +    guest_add_parser.add_argument('--guest', action='store', type=str,
> +                                  help='Name of the guest')
> +    guest_add_parser.add_argument('--qmp', action='store', type=str,
> +                                  help='Path of socket')
> +    guest_add_parser.set_defaults(func=backup_tool.guest_add_wrapper)
> +
> +    guest_remove_parser = guest_subparsers.add_parser('remove',
> +                                                      help='removes a guest')
> +    guest_remove_parser.add_argument('--guest', action='store', type=str,
> +                                     help='Name of the guest')
> +    guest_remove_parser.set_defaults(func=backup_tool.guest_remove_wrapper)
> +
> +    drive_parser = subparsers.add_parser('drive',
> +                                         help='Adds drive(s) for backup')
> +    drive_subparsers = drive_parser.add_subparsers(title='Add subparser',
> +                                                   description='Drive \
> +                                                                subparser')
> +    drive_add_parser = drive_subparsers.add_parser('add',
> +                                                   help='Adds new \
> +                                                         drive for backup')
> +    drive_add_parser.add_argument('--guest', action='store',
> +                                  type=str, help='Name of the guest')
> +    drive_add_parser.add_argument('--id', action='store',
> +                                  type=str, help='Drive ID')
> +    drive_add_parser.add_argument('--target', nargs='?',
> +                                  default=None, help='Destination path')
> +    drive_add_parser.set_defaults(func=backup_tool.drive_add_wrapper)
> +
> +    backup_parser = subparsers.add_parser('backup', help='Creates backup')
> +    backup_parser.add_argument('--guest', action='store',
> +                               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)
> +
> +if __name__ == '__main__':
> +    main()
> -- 
> 2.7.4
> 

Re: [Qemu-devel] [PATCH 1/3] backup: QEMU Backup Tool

[Ishani]

----- On Aug 22, 2017, at 7:43 PM, stefanha stefanha@redhat.com wrote:

> On Mon, Aug 21, 2017 at 04:40:37PM +0530, Ishani Chugh wrote:
>> 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.ishani@research.iiit.ac.in>
>> ---
>>  contrib/backup/qemu-backup.py | 334 ++++++++++++++++++++++++++++++++++++++++++
>>  1 file changed, 334 insertions(+)
>>  create mode 100644 contrib/backup/qemu-backup.py
>> 
>> diff --git a/contrib/backup/qemu-backup.py b/contrib/backup/qemu-backup.py
>> new file mode 100644
>> index 0000000..08570f7
>> --- /dev/null
>> +++ b/contrib/backup/qemu-backup.py
>> @@ -0,0 +1,334 @@
>> +#!/usr/bin/python
>> +# -*- coding: utf-8 -*-
>> +#
>> +# Copyright (C) 2017 Ishani Chugh <chugh.ishani@research.iiit.ac.in>
>> +#
>> +# 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
>> +try:
>> +    import configparser
>> +except ImportError:
>> +    import ConfigParser as configparser
>> +import sys
>> +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=os.path.expanduser('~') +
>> +                 '/.config/qemu/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.dirname(self.config_file)):
>> +                    os.makedirs(os.path.dirname(self.config_file))
>> +            except:
>> +                print("Cannot create config directory", file=sys.stderr)
>> +                sys.exit(1)
>> +        self.config = configparser.ConfigParser()
>> +        self.config.read(self.config_file)
>> +
>> +    def write_config(self):
>> +        """
>> +        Writes configuration to ini 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_address(self, socket_address):
>> +        """
>> +        Return Socket address in form of string or tuple
>> +        """
>> +        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):
>> +        """
>> +        Performs full backup of guest
>> +        """
>> +        if guest_name not in self.config.sections():
>> +            print("Cannot find specified guest", file=sys.stderr)
>> +            sys.exit(1)
>> +
>> +        self.verify_guest_running(guest_name)
>> +        connection = QEMUMonitorProtocol(
>> +                                         self.get_socket_address(
>> +                                             self.config[guest_name]['qmp']))
>> +        connection.connect()
>> +        cmd = {"execute": "transaction", "arguments": {"actions": []}}
>> +        drive_list = []
>> +        for key in self.config[guest_name]:
>> +            if key.startswith("drive_"):
>> +                drive = key[len('drive_'):]
>> +                drive_list.append(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)
>> +        qmp_return = connection.cmd_obj(cmd)
>> +        if 'error' in qmp_return:
>> +            print(qmp_return['error']['desc'], file=sys.stderr)
>> +            sys.exit(1)
>> +        print("Backup Started")
>> +        while len(drive_list) != 0:
>> +            event = connection.pull_event(wait=True)
>> +            if event['event'] == 'SHUTDOWN':
>> +                print("The guest was SHUT DOWN", file=sys.stderr)
>> +                sys.exit(1)
>> +
>> +            if event['event'] == 'RESET':
>> +                print("The guest was Rebooted", file=sys.stderr)
>> +                sys.exit(1)
>> +
>> +            if event['data']['device'] in drive_list and \
>> +                    event['data']['type'] == 'backup':
> 
> At this point the event[] dict might be a non-BLOCK_JOB_* event.
> Therefore event['data']['device'] will raise a KeyError exception.
> 
> You must check event['event'] before assuming it contains certain
> fields.

Agreed. Will fix in next revision.
 
>> +                if event['event'] == 'BLOCK_JOB_COMPLETED':
>> +                    print("*"+event['data']['device'])
>> +                    drive_list.remove(event['data']['device'])
>> +                elif event['event'] == 'BLOCK_JOB_ERROR':
>> +                    print("Cannot Complete Backup", file=sys.stderr)
>> +                    sys.exit(1)
>> +        print("Backup Complete")
>> +
>> +    def _drive_add(self, drive_id, guest_name, target=None):
>> +        """
>> +        Adds drive for backup
>> +        """
>> +        if target is None:
>> +            target = os.path.abspath(drive_id)
>> +
>> +        if os.path.isdir(os.path.dirname(target)) is False:
>> +            print("Cannot find target directory", file=sys.stderr)
>> +            sys.exit(1)
>> +
>> +        if guest_name not in self.config.sections():
>> +            print("Cannot find specified guest", file=sys.stderr)
>> +            sys.exit(1)
>> +
>> +        if "drive_"+drive_id in self.config[guest_name]:
>> +            print("Drive already marked for backup", file=sys.stderr)
>> +            sys.exit(1)
>> +
>> +        self.verify_guest_running(guest_name)
>> +
>> +        connection = QEMUMonitorProtocol(
>> +                                         self.get_socket_address(
>> +                                             self.config[guest_name]['qmp']))
>> +        connection.connect()
>> +        cmd = {'execute': 'query-block'}
>> +        returned_json = connection.cmd_obj(cmd)
>> +        device_present = False
>> +        for device in returned_json['return']:
>> +            if device['device'] == drive_id:
>> +                device_present = True
>> +                break
>> +
>> +        if not device_present:
>> +            print("No such drive in guest", file=sys.stderr)
>> +            sys.exit(1)
>> +
>> +        drive_id = "drive_" + drive_id
>> +        for d_id in self.config[guest_name]:
>> +            if self.config[guest_name][d_id] == target:
>> +                print("Please choose different target", file=sys.stderr)
>> +                sys.exit(1)
>> +        self.config.set(guest_name, drive_id, target)
>> +        self.write_config()
>> +        print("Successfully Added Drive")
>> +
>> +    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_address(
>> +                                             socket_address))
>> +            connection.connect()
>> +        except socket_error:
>> +            if socket_error.errno != errno.ECONNREFUSED:
>> +                print("Connection to guest refused", file=sys.stderr)
>> +                sys.exit(1)
>> +
>> +    def _guest_add(self, guest_name, socket_address):
>> +        """
>> +        Adds a guest to the config file
>> +        """
>> +        if guest_name in self.config.sections():
>> +            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):
>> +        """
>> +        Removes a guest from config file
>> +        """
>> +        if guest_name not in self.config.sections():
>> +            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)
>> +            sys.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)
> 
> I suggest print('Replace ' + location + ' with ' + target) for a
> slightly clearer message.

Will fix in next revision.

>> +
>> +                if not device_present:
>> +                    print("No such drive in guest", file=sys.stderr)
>> +                    sys.exit(1)
> 
> Since the command itself requires the guest to be running
> users are very likely to manipulate the disk image files while the guest
> is running.
> 
> This command must prompt the user to shut down the guest before
> restoring.

The intention behind this condition is the case where user may have detached
a disk from the guest(and have rerun the guest). I will put up the message to
shut down the guest. 

>> +
>> +    def guest_remove_wrapper(self, args):
>> +        """
>> +        Wrapper for _guest_remove method.
>> +        """
>> +        guest_name = args.guest
>> +        self._guest_remove(guest_name)
>> +        self.write_config()
>> +
>> +    def list(self, args):
>> +        """
>> +        Prints guests present in Config file
>> +        """
>> +        for guest_name in self.config.sections():
>> +            print(guest_name)
>> +
>> +    def guest_add_wrapper(self, args):
>> +        """
>> +        Wrapper for _quest_add method
>> +        """
>> +        self._guest_add(args.guest, args.qmp)
>> +
>> +    def drive_add_wrapper(self, args):
>> +        """
>> +        Wrapper for _drive_add method
>> +        """
>> +        self._drive_add(args.id, args.guest, args.target)
>> +
>> +    def fullbackup_wrapper(self, args):
>> +        """
>> +        Wrapper for _full_backup method
>> +        """
>> +        self._full_backup(args.guest)
>> +
>> +    def restore_wrapper(self, args):
>> +        """
>> +        Wrapper for restore
>> +        """
>> +        self._restore(args.guest)
>> +
>> +
>> +def main():
>> +    backup_tool = BackupTool()
>> +    parser = ArgumentParser()
>> +    subparsers = parser.add_subparsers(title='Subcommands',
>> +                                       description='Valid Subcommands',
>> +                                       help='Subcommand help')
>> +    guest_parser = subparsers.add_parser('guest', help='Adds or \
>> +                                                   removes and lists guest(s)')
>> +    guest_subparsers = guest_parser.add_subparsers(title='Guest Subparser')
>> +    guest_list_parser = guest_subparsers.add_parser('list',
>> +                                                    help='Lists all guests')
>> +    guest_list_parser.set_defaults(func=backup_tool.list)
>> +
>> +    guest_add_parser = guest_subparsers.add_parser('add', help='Adds a guest')
>> +    guest_add_parser.add_argument('--guest', action='store', type=str,
>> +                                  help='Name of the guest')
>> +    guest_add_parser.add_argument('--qmp', action='store', type=str,
>> +                                  help='Path of socket')
>> +    guest_add_parser.set_defaults(func=backup_tool.guest_add_wrapper)
>> +
>> +    guest_remove_parser = guest_subparsers.add_parser('remove',
>> +                                                      help='removes a guest')
>> +    guest_remove_parser.add_argument('--guest', action='store', type=str,
>> +                                     help='Name of the guest')
>> +    guest_remove_parser.set_defaults(func=backup_tool.guest_remove_wrapper)
>> +
>> +    drive_parser = subparsers.add_parser('drive',
>> +                                         help='Adds drive(s) for backup')
>> +    drive_subparsers = drive_parser.add_subparsers(title='Add subparser',
>> +                                                   description='Drive \
>> +                                                                subparser')
>> +    drive_add_parser = drive_subparsers.add_parser('add',
>> +                                                   help='Adds new \
>> +                                                         drive for backup')
>> +    drive_add_parser.add_argument('--guest', action='store',
>> +                                  type=str, help='Name of the guest')
>> +    drive_add_parser.add_argument('--id', action='store',
>> +                                  type=str, help='Drive ID')
>> +    drive_add_parser.add_argument('--target', nargs='?',
>> +                                  default=None, help='Destination path')
>> +    drive_add_parser.set_defaults(func=backup_tool.drive_add_wrapper)
>> +
>> +    backup_parser = subparsers.add_parser('backup', help='Creates backup')
>> +    backup_parser.add_argument('--guest', action='store',
>> +                               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)
>> +
>> +if __name__ == '__main__':
>> +    main()
>> --
>> 2.7.4

Thanks for review.