Add qemu-ga-client script

This is an easy-to-use QEMU guest agent client written in
Python. It simply provides commands to call guest agent
functions like ping, fsfreeze and shutdown. Additionally,
it provides extra useful commands, e.g, cat, ifconfig and
reboot, by using guet agent functions.

Examples:
  $ export QGA_CLIENT_ADDRESS=/tmp/qga.sock
  $ qemu-ga-client ping

  $ qemu-ga-client cat /etc/resolv.conf
  # Generated by NetworkManager
  nameserver 10.0.2.3

  $ qemu-ga-client fsfreeze status
  thawed
  $ qemu-ga-client fsfreeze freeze
  2 filesystems frozen

The script communicates with a guest agent by means of
qmp.QEMUMonitorProtocol. Every commands are called with
timeout (3 sec.) to avoid blocking. The script always
calls sync command prior to issuing an actual command
(except for ping which doesn't need sync).

Signed-off-by: Ryota Ozaki <ozaki.ryota@gmail.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>

1 files changed, 299 insertions, 0 deletions

diff --git a/QMP/qemu-ga-client b/QMP/qemu-ga-client
new file mode 100755
index 0000000..46676c3
--- /dev/null
+++ b/QMP/qemu-ga-client
@@ -0,0 +1,299 @@
+#!/usr/bin/python
+
+# QEMU Guest Agent Client
+#
+# Copyright (C) 2012 Ryota Ozaki <ozaki.ryota@gmail.com>
+#
+# This work is licensed under the terms of the GNU GPL, version 2.  See
+# the COPYING file in the top-level directory.
+#
+# Usage:
+#
+# Start QEMU with:
+#
+# # qemu [...] -chardev socket,path=/tmp/qga.sock,server,nowait,id=qga0 \
+#   -device virtio-serial -device virtserialport,chardev=qga0,name=org.qemu.guest_agent.0
+#
+# Run the script:
+#
+# $ qemu-ga-client --address=/tmp/qga.sock <command> [args...]
+#
+# or
+#
+# $ export QGA_CLIENT_ADDRESS=/tmp/qga.sock
+# $ qemu-ga-client <command> [args...]
+#
+# For example:
+#
+# $ qemu-ga-client cat /etc/resolv.conf
+# # Generated by NetworkManager
+# nameserver 10.0.2.3
+# $ qemu-ga-client fsfreeze status
+# thawed
+# $ qemu-ga-client fsfreeze freeze
+# 2 filesystems frozen
+#
+# See also: http://wiki.qemu.org/Features/QAPI/GuestAgent
+#
+
+import base64
+import random
+
+import qmp
+
+
+class QemuGuestAgent(qmp.QEMUMonitorProtocol):
+    def __getattr__(self, name):
+        def wrapper(**kwds):
+            return self.command('guest-' + name.replace('_', '-'), **kwds)
+        return wrapper
+
+
+class QemuGuestAgentClient:
+    error = QemuGuestAgent.error
+
+    def __init__(self, address):
+        self.qga = QemuGuestAgent(address)
+        self.qga.connect(negotiate=False)
+
+    def sync(self, timeout=3):
+        # Avoid being blocked forever
+        if not self.ping(timeout):
+            raise EnvironmentError('Agent seems not alive')
+        uid = random.randint(0, (1 << 32) - 1)
+        while True:
+            ret = self.qga.sync(id=uid)
+            if isinstance(ret, int) and int(ret) == uid:
+                break
+
+    def __file_read_all(self, handle):
+        eof = False
+        data = ''
+        while not eof:
+            ret = self.qga.file_read(handle=handle, count=1024)
+            _data = base64.b64decode(ret['buf-b64'])
+            data += _data
+            eof = ret['eof']
+        return data
+
+    def read(self, path):
+        handle = self.qga.file_open(path=path)
+        try:
+            data = self.__file_read_all(handle)
+        finally:
+            self.qga.file_close(handle=handle)
+        return data
+
+    def info(self):
+        info = self.qga.info()
+
+        msgs = []
+        msgs.append('version: ' + info['version'])
+        msgs.append('supported_commands:')
+        enabled = [c['name'] for c in info['supported_commands'] if c['enabled']]
+        msgs.append('\tenabled: ' + ', '.join(enabled))
+        disabled = [c['name'] for c in info['supported_commands'] if not c['enabled']]
+        msgs.append('\tdisabled: ' + ', '.join(disabled))
+
+        return '\n'.join(msgs)
+
+    def __gen_ipv4_netmask(self, prefixlen):
+        mask = int('1' * prefixlen + '0' * (32 - prefixlen), 2)
+        return '.'.join([str(mask >> 24),
+                         str((mask >> 16) & 0xff),
+                         str((mask >> 8) & 0xff),
+                         str(mask & 0xff)])
+
+    def ifconfig(self):
+        nifs = self.qga.network_get_interfaces()
+
+        msgs = []
+        for nif in nifs:
+            msgs.append(nif['name'] + ':')
+            if 'ip-addresses' in nif:
+                for ipaddr in nif['ip-addresses']:
+                    if ipaddr['ip-address-type'] == 'ipv4':
+                        addr = ipaddr['ip-address']
+                        mask = self.__gen_ipv4_netmask(int(ipaddr['prefix']))
+                        msgs.append("\tinet %s  netmask %s" % (addr, mask))
+                    elif ipaddr['ip-address-type'] == 'ipv6':
+                        addr = ipaddr['ip-address']
+                        prefix = ipaddr['prefix']
+                        msgs.append("\tinet6 %s  prefixlen %s" % (addr, prefix))
+            if nif['hardware-address'] != '00:00:00:00:00:00':
+                msgs.append("\tether " + nif['hardware-address'])
+
+        return '\n'.join(msgs)
+
+    def ping(self, timeout):
+        self.qga.settimeout(timeout)
+        try:
+            self.qga.ping()
+        except self.qga.timeout:
+            return False
+        return True
+
+    def fsfreeze(self, cmd):
+        if cmd not in ['status', 'freeze', 'thaw']:
+            raise StandardError('Invalid command: ' + cmd)
+
+        return getattr(self.qga, 'fsfreeze' + '_' + cmd)()
+
+    def fstrim(self, minimum=0):
+        return getattr(self.qga, 'fstrim')(minimum=minimum)
+
+    def suspend(self, mode):
+        if mode not in ['disk', 'ram', 'hybrid']:
+            raise StandardError('Invalid mode: ' + mode)
+
+        try:
+            getattr(self.qga, 'suspend' + '_' + mode)()
+            # On error exception will raise
+        except self.qga.timeout:
+            # On success command will timed out
+            return
+
+    def shutdown(self, mode='powerdown'):
+        if mode not in ['powerdown', 'halt', 'reboot']:
+            raise StandardError('Invalid mode: ' + mode)
+
+        try:
+            self.qga.shutdown(mode=mode)
+        except self.qga.timeout:
+            return
+
+
+def _cmd_cat(client, args):
+    if len(args) != 1:
+        print('Invalid argument')
+        print('Usage: cat <file>')
+        sys.exit(1)
+    print(client.read(args[0]))
+
+
+def _cmd_fsfreeze(client, args):
+    usage = 'Usage: fsfreeze status|freeze|thaw'
+    if len(args) != 1:
+        print('Invalid argument')
+        print(usage)
+        sys.exit(1)
+    if args[0] not in ['status', 'freeze', 'thaw']:
+        print('Invalid command: ' + args[0])
+        print(usage)
+        sys.exit(1)
+    cmd = args[0]
+    ret = client.fsfreeze(cmd)
+    if cmd == 'status':
+        print(ret)
+    elif cmd == 'freeze':
+        print("%d filesystems frozen" % ret)
+    else:
+        print("%d filesystems thawed" % ret)
+
+
+def _cmd_fstrim(client, args):
+    if len(args) == 0:
+        minimum = 0
+    else:
+        minimum = int(args[0])
+    print(client.fstrim(minimum))
+
+
+def _cmd_ifconfig(client, args):
+    print(client.ifconfig())
+
+
+def _cmd_info(client, args):
+    print(client.info())
+
+
+def _cmd_ping(client, args):
+    if len(args) == 0:
+        timeout = 3
+    else:
+        timeout = float(args[0])
+    alive = client.ping(timeout)
+    if not alive:
+        print("Not responded in %s sec" % args[0])
+        sys.exit(1)
+
+
+def _cmd_suspend(client, args):
+    usage = 'Usage: suspend disk|ram|hybrid'
+    if len(args) != 1:
+        print('Less argument')
+        print(usage)
+        sys.exit(1)
+    if args[0] not in ['disk', 'ram', 'hybrid']:
+        print('Invalid command: ' + args[0])
+        print(usage)
+        sys.exit(1)
+    client.suspend(args[0])
+
+
+def _cmd_shutdown(client, args):
+    client.shutdown()
+_cmd_powerdown = _cmd_shutdown
+
+
+def _cmd_halt(client, args):
+    client.shutdown('halt')
+
+
+def _cmd_reboot(client, args):
+    client.shutdown('reboot')
+
+
+commands = [m.replace('_cmd_', '') for m in dir() if '_cmd_' in m]
+
+
+def main(address, cmd, args):
+    if not os.path.exists(address):
+        print('%s not found' % address)
+        sys.exit(1)
+
+    if cmd not in commands:
+        print('Invalid command: ' + cmd)
+        print('Available commands: ' + ', '.join(commands))
+        sys.exit(1)
+
+    try:
+        client = QemuGuestAgentClient(address)
+    except QemuGuestAgent.error, e:
+        import errno
+
+        print(e)
+        if e.errno == errno.ECONNREFUSED:
+            print('Hint: qemu is not running?')
+        sys.exit(1)
+
+    if cmd != 'ping':
+        client.sync()
+
+    globals()['_cmd_' + cmd](client, args)
+
+
+if __name__ == '__main__':
+    import sys
+    import os
+    import optparse
+
+    address = os.environ['QGA_CLIENT_ADDRESS'] if 'QGA_CLIENT_ADDRESS' in os.environ else None
+
+    usage = "%prog [--address=<unix_path>|<ipv4_address>] <command> [args...]\n"
+    usage += '<command>: ' + ', '.join(commands)
+    parser = optparse.OptionParser(usage=usage)
+    parser.add_option('--address', action='store', type='string',
+                      default=address, help='Specify a ip:port pair or a unix socket path')
+    options, args = parser.parse_args()
+
+    address = options.address
+    if address is None:
+        parser.error('address is not specified')
+        sys.exit(1)
+
+    if len(args) == 0:
+        parser.error('Less argument')
+        sys.exit(1)
+
+    main(address, args[0], args[1:])