virt-manager/virt-xml
Cole Robinson 53f075ab76 virt-xml: Warn if libvirt discards our defined changes
This can happen if we try to remove a default device, like
 a ps2 mouse on x86, but it can happen for many other reasons as well

https://bugzilla.redhat.com/show_bug.cgi?id=1405263
2019-06-16 17:08:59 -04:00

574 lines
18 KiB
Python
Executable File

#!/usr/bin/env python3
#
# Copyright 2013-2014 Red Hat, Inc.
#
# This work is licensed under the GNU GPLv2 or later.
# See the COPYING file in the top-level directory.
import difflib
import logging
import re
import sys
import libvirt
import virtinst
from virtinst import cli
from virtinst import xmlutil
from virtinst.cli import fail, print_stdout, print_stderr
###################
# Utility helpers #
###################
def prompt_yes_or_no(msg):
while 1:
printmsg = msg + " (y/n): "
sys.stdout.write(printmsg)
sys.stdout.flush()
inp = sys.stdin.readline().lower().strip()
if inp in ["y", "yes"]:
return True
elif inp in ["n", "no"]:
return False
else:
print_stdout(_("Please enter 'yes' or 'no'."))
def get_diff(origxml, newxml):
ret = "".join(difflib.unified_diff(origxml.splitlines(1),
newxml.splitlines(1),
fromfile="Original XML",
tofile="Altered XML"))
if ret:
logging.debug("XML diff:\n%s", ret)
else:
logging.debug("No XML diff, didn't generate any change.")
return ret
def set_os_variant(options, guest):
if options.os_variant is None:
return
osdata = cli.parse_os_variant(options.os_variant)
if osdata.name:
guest.set_os_name(osdata.name)
def get_xmldesc(domain, inactive=False):
flags = libvirt.VIR_DOMAIN_XML_SECURE
if inactive:
flags |= libvirt.VIR_DOMAIN_XML_INACTIVE
return domain.XMLDesc(flags)
def get_domain_and_guest(conn, domstr):
try:
int(domstr)
isint = True
except ValueError:
isint = False
uuidre = "[a-fA-F0-9]{8}[-]([a-fA-F0-9]{4}[-]){3}[a-fA-F0-9]{12}$"
isuuid = bool(re.match(uuidre, domstr))
try:
domain = None
try:
domain = conn.lookupByName(domstr)
except Exception:
# In case the VM has a UUID or ID for a name
logging.debug("Error looking up domain by name", exc_info=True)
if isint:
domain = conn.lookupByID(int(domstr))
elif isuuid:
domain = conn.lookupByUUIDString(domstr)
else:
raise
except libvirt.libvirtError as e:
fail(_("Could not find domain '%s': %s") % (domstr, e))
state = domain.info()[0]
active_xmlobj = None
inactive_xmlobj = virtinst.Guest(conn, parsexml=get_xmldesc(domain))
if state != libvirt.VIR_DOMAIN_SHUTOFF:
active_xmlobj = inactive_xmlobj
inactive_xmlobj = virtinst.Guest(conn,
parsexml=get_xmldesc(domain, inactive=True))
return (domain, inactive_xmlobj, active_xmlobj)
def defined_xml_is_unchanged(conn, domain, original_xml):
rawxml = get_xmldesc(domain, inactive=True)
new_xml = virtinst.Guest(conn, parsexml=rawxml)
return new_xml != original_xml
################
# Change logic #
################
def _find_objects_to_edit(guest, action_name, editval, parserclass):
objlist = xmlutil.listify(parserclass.lookup_prop(guest))
idx = None
if editval is None:
idx = 1
elif (editval.isdigit() or
editval.startswith("-") and editval[1:].isdigit()):
idx = int(editval)
if idx is not None:
# Edit device by index
if idx == 0:
fail(_("Invalid --edit option '%s'") % editval)
if not objlist:
fail(_("No --%s objects found in the XML") %
parserclass.cli_arg_name)
if len(objlist) < abs(idx):
fail(_("--edit %s requested but there's only %s "
"--%s object in the XML") %
(idx, len(objlist), parserclass.cli_arg_name))
if idx > 0:
idx -= 1
inst = objlist[idx]
elif editval == "all":
# Edit 'all' devices
inst = objlist[:]
else:
# Lookup device by the passed prop string
parserobj = parserclass(editval, guest=guest)
inst = parserobj.lookup_child_from_option_string()
if not inst:
fail(_("No matching objects found for --%s %s") %
(action_name, editval))
return inst
def check_action_collision(options):
actions = ["edit", "add-device", "remove-device", "build-xml"]
collisions = []
for cliname in actions:
optname = cliname.replace("-", "_")
if getattr(options, optname) not in [False, -1]:
collisions.append(cliname)
if len(collisions) == 0:
fail(_("One of %s must be specified.") %
", ".join(["--" + c for c in actions]))
if len(collisions) > 1:
fail(_("Conflicting options %s") %
", ".join(["--" + c for c in collisions]))
def check_xmlopt_collision(options):
collisions = []
for parserclass in cli.VIRT_PARSERS:
if getattr(options, parserclass.cli_arg_name):
collisions.append(parserclass)
if len(collisions) == 0:
fail(_("No change specified."))
if len(collisions) != 1:
fail(_("Only one change operation may be specified "
"(conflicting options %s)") %
[c.cli_flag_name() for c in collisions])
return collisions[0]
def action_edit(guest, options, parserclass):
if parserclass.guest_propname:
inst = _find_objects_to_edit(guest, "edit", options.edit, parserclass)
else:
inst = guest
if options.edit and options.edit != '1' and options.edit != 'all':
fail(_("'--edit %s' doesn't make sense with --%s, "
"just use empty '--edit'") %
(options.edit, parserclass.cli_arg_name))
if options.os_variant is not None:
fail(_("--os-variant is not supported with --edit"))
return cli.parse_option_strings(options, guest, inst, editing=True)
def action_add_device(guest, options, parserclass):
if not parserclass.prop_is_list(guest):
fail(_("Cannot use --add-device with --%s") % parserclass.cli_arg_name)
set_os_variant(options, guest)
devs = cli.parse_option_strings(options, guest, None)
devs = xmlutil.listify(devs)
for dev in devs:
dev.set_defaults(guest)
return devs
def action_remove_device(guest, options, parserclass):
if not parserclass.prop_is_list(guest):
fail(_("Cannot use --remove-device with --%s") %
parserclass.cli_arg_name)
if options.os_variant is not None:
fail(_("--os-variant is not supported with --remove-device"))
devs = _find_objects_to_edit(guest, "remove-device",
getattr(options, parserclass.cli_arg_name)[-1], parserclass)
devs = xmlutil.listify(devs)
for dev in devs:
guest.remove_device(dev)
return devs
def action_build_xml(conn, options, parserclass, guest):
if not parserclass.guest_propname:
fail(_("--build-xml not supported for --%s") %
parserclass.cli_arg_name)
if options.os_variant is not None:
fail(_("--os-variant is not supported with --build-xml"))
inst = parserclass.lookup_prop(guest)
if parserclass.prop_is_list(guest):
inst = inst.new()
else:
inst = inst.__class__(conn)
devs = cli.parse_option_strings(options, guest, inst)
devs = xmlutil.listify(devs)
for dev in devs:
dev.set_defaults(guest)
return devs
def setup_device(dev):
if getattr(dev, "DEVICE_TYPE", None) != "disk":
return
logging.debug("Doing setup for disk=%s", dev)
dev.build_storage(cli.get_meter())
def define_changes(conn, inactive_xmlobj, devs, action, confirm):
if confirm:
if not prompt_yes_or_no(
_("Define '%s' with the changed XML?") % inactive_xmlobj.name):
return False
if action == "hotplug":
for dev in devs:
setup_device(dev)
dom = conn.defineXML(inactive_xmlobj.get_xml())
print_stdout(_("Domain '%s' defined successfully.") % inactive_xmlobj.name)
return dom
def start_domain_transient(conn, xmlobj, devs, action, confirm):
if confirm:
if not prompt_yes_or_no(
_("Start '%s' with the changed XML?") % xmlobj.name):
return False
if action == "hotplug":
for dev in devs:
setup_device(dev)
try:
dom = conn.createXML(xmlobj.get_xml())
except libvirt.libvirtError as e:
fail(_("Failed starting domain '%s': %s") % (xmlobj.name, e))
else:
print_stdout(_("Domain '%s' started successfully.") % xmlobj.name)
return dom
def update_changes(domain, devs, action, confirm):
for dev in devs:
xml = dev.get_xml()
if confirm:
if action == "hotplug":
prep = "to"
elif action == "hotunplug":
prep = "from"
else:
prep = "for"
msg = ("%s\n\n%s this device %s guest '%s'?" %
(xml, action.capitalize(), prep, domain.name()))
if not prompt_yes_or_no(msg):
continue
if action == "hotplug":
setup_device(dev)
try:
if action == "hotplug":
domain.attachDeviceFlags(xml, libvirt.VIR_DOMAIN_AFFECT_LIVE)
elif action == "hotunplug":
domain.detachDeviceFlags(xml, libvirt.VIR_DOMAIN_AFFECT_LIVE)
elif action == "update":
domain.updateDeviceFlags(xml, libvirt.VIR_DOMAIN_AFFECT_LIVE)
except libvirt.libvirtError as e:
fail(_("Error attempting device %s: %s") % (action, e))
# Test driver doesn't support device hotplug so we can't reach this
print_stdout(_("Device %s successful.") % action) # pragma: no cover
if confirm: # pragma: no cover
print_stdout("")
def prepare_changes(xmlobj, options, parserclass):
origxml = xmlobj.get_xml()
if options.edit != -1:
devs = action_edit(xmlobj, options, parserclass)
action = "update"
elif options.add_device:
devs = action_add_device(xmlobj, options, parserclass)
action = "hotplug"
elif options.remove_device:
devs = action_remove_device(xmlobj, options, parserclass)
action = "hotunplug"
newxml = xmlobj.get_xml()
diff = get_diff(origxml, newxml)
if not diff:
logging.warning(_("No XML diff was generated. The requested "
"changes will have no effect."))
if options.print_diff:
if diff:
print_stdout(diff)
elif options.print_xml:
print_stdout(newxml)
return devs, action
#######################
# CLI option handling #
#######################
def parse_args():
parser = cli.setupParser(
"%(prog)s [options]",
_("Edit libvirt XML using command line options."),
introspection_epilog=True)
cli.add_connect_option(parser, "virt-xml")
parser.add_argument("domain", nargs='?',
help=_("Domain name, id, or uuid"))
actg = parser.add_argument_group(_("XML actions"))
actg.add_argument("--edit", nargs='?', default=-1,
help=_("Edit VM XML. Examples:\n"
"--edit --disk ... (edit first disk device)\n"
"--edit 2 --disk ... (edit second disk device)\n"
"--edit all --disk ... (edit all disk devices)\n"
"--edit target=hda --disk ... (edit disk 'hda')\n"))
actg.add_argument("--remove-device", action="store_true",
help=_("Remove specified device. Examples:\n"
"--remove-device --disk 1 (remove first disk)\n"
"--remove-device --disk all (remove all disks)\n"
"--remove-device --disk /some/path"))
actg.add_argument("--add-device", action="store_true",
help=_("Add specified device. Example:\n"
"--add-device --disk ..."))
actg.add_argument("--build-xml", action="store_true",
help=_("Output built device XML. Domain is optional but "
"recommended to ensure optimal defaults."))
outg = parser.add_argument_group(_("Output options"))
outg.add_argument("--update", action="store_true",
help=_("Apply changes to the running VM.\n"
"With --add-device, this is a hotplug operation.\n"
"With --remove-device, this is a hotunplug operation.\n"
"With --edit, this is an update device operation."))
define_g = outg.add_mutually_exclusive_group()
define_g.add_argument("--define", action="store_true",
help=_("Force defining the domain. Only required if a --print "
"option was specified."))
define_g.add_argument("--no-define", dest='define', action="store_false",
help=_("Force not defining the domain."))
define_g.set_defaults(define=None)
outg.add_argument("--start", action="store_true",
help=_("Start the domain."))
outg.add_argument("--print-diff", action="store_true",
help=_("Only print the requested change, in diff format"))
outg.add_argument("--print-xml", action="store_true",
help=_("Only print the requested change, in full XML format"))
outg.add_argument("--confirm", action="store_true",
help=_("Require confirmation before saving any results."))
cli.add_os_variant_option(parser, virtinstall=False)
g = parser.add_argument_group(_("XML options"))
cli.add_disk_option(g, editexample=True)
cli.add_net_option(g)
cli.add_gfx_option(g)
cli.add_metadata_option(g)
cli.add_memory_option(g)
cli.vcpu_cli_options(g, editexample=True)
cli.add_guest_xml_options(g)
cli.add_boot_options(g)
cli.add_device_options(g)
misc = parser.add_argument_group(_("Miscellaneous Options"))
cli.add_misc_options(misc, prompt=False, printxml=False, dryrun=False)
cli.autocomplete(parser)
return parser.parse_args()
###################
# main() handling #
###################
def main(conn=None):
cli.earlyLogging()
options = parse_args()
if (options.confirm or options.print_xml or
options.print_diff or options.build_xml):
options.quiet = False
cli.setupLogging("virt-xml", options.debug, options.quiet)
if cli.check_option_introspection(options):
return 0
options.stdinxml = None
if not options.domain and not options.build_xml:
if not sys.stdin.closed and not sys.stdin.isatty():
if options.confirm:
fail(_("Can't use --confirm with stdin input."))
if options.update:
fail(_("Can't use --update with stdin input."))
options.stdinxml = sys.stdin.read()
else:
fail(_("A domain must be specified"))
# Default to --define, unless:
# --no-define explicitly specified
# --print-* option is used
# XML input came from stdin
if not options.print_xml and not options.print_diff:
if options.stdinxml:
if not options.define:
options.print_xml = True
else:
if options.define is None:
options.define = True
if options.confirm and not options.print_xml:
options.print_diff = True
# Ensure only one of these actions wash specified
# --edit
# --remove-device
# --add-device
# --build-xml
check_action_collision(options)
# Ensure there wasn't more than one device/xml config option
# specified. So reject '--disk X --network X'
parserclass = check_xmlopt_collision(options)
if options.update and not parserclass.guest_propname:
fail(_("Don't know how to --update for --%s") %
(parserclass.cli_arg_name))
conn = cli.getConnection(options.connect, conn)
domain = None
active_xmlobj = None
inactive_xmlobj = None
if options.domain:
domain, inactive_xmlobj, active_xmlobj = get_domain_and_guest(
conn, options.domain)
else:
inactive_xmlobj = virtinst.Guest(conn, parsexml=options.stdinxml)
vm_is_running = bool(active_xmlobj)
if options.build_xml:
devs = action_build_xml(conn, options, parserclass, inactive_xmlobj)
for dev in devs:
# pylint: disable=no-member
print_stdout(dev.get_xml())
return 0
performed_update = False
if options.update:
if options.update and options.start:
fail(_("Cannot mix --update and --start"))
if vm_is_running:
devs, action = prepare_changes(active_xmlobj, options, parserclass)
update_changes(domain, devs, action, options.confirm)
performed_update = True
else:
logging.warning(
_("The VM is not running, --update is inapplicable."))
if not options.define:
# --update and --no-define passed, so we are done
# It's hard to hit this case with the test suite
return 0 # pragma: no cover
original_xml = inactive_xmlobj.get_xml()
devs, action = prepare_changes(inactive_xmlobj, options, parserclass)
if not options.define:
if options.start:
start_domain_transient(conn, inactive_xmlobj, devs,
action, options.confirm)
return 0
dom = define_changes(conn, inactive_xmlobj,
devs, action, options.confirm)
if not dom:
# --confirm user said 'no'
return 0
if options.start:
try:
dom.create()
except libvirt.libvirtError as e: # pragma: no cover
fail(_("Failed starting domain '%s': %s") % (
inactive_xmlobj.name, e))
print_stdout(_("Domain '%s' started successfully.") %
inactive_xmlobj.name)
elif vm_is_running and not performed_update:
print_stdout(
_("Changes will take effect after the domain is fully powered off."))
elif defined_xml_is_unchanged(conn, domain, original_xml):
logging.warning(_("XML did not change after domain define. You may "
"have changed a value that libvirt is setting by default."))
return 0
if __name__ == "__main__": # pragma: no cover
try:
sys.exit(main())
except SystemExit as sys_e:
sys.exit(sys_e.code)
except KeyboardInterrupt:
logging.debug("", exc_info=True)
print_stderr(_("Aborted at user request"))
except Exception as main_e:
fail(main_e)