virt-manager/virtManager/inspection.py
Radostin Stoyanov b93cc3bbc9 pycodestyle: Do not use bare 'except:'
A bare 'except:' catches all exceptions [1], including SystemExit,
KeyboardInterrupt, and GeneratorExit (which is not an error and should
not normally be caught by user code). In situations where you need to
catch all “normal” errors, you can catch the base class for all normal
exceptions, Exception [2].

[1] https://docs.python.org/2/howto/doanddont.html#except
[2] https://docs.python.org/2/library/exceptions.html#Exception
2017-08-02 13:57:43 -04:00

275 lines
9.5 KiB
Python

#
# Copyright (C) 2011, 2013 Red Hat, Inc.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
# MA 02110-1301 USA.
#
from Queue import Queue
from threading import Thread
import logging
from guestfs import GuestFS # pylint: disable=import-error
from .baseclass import vmmGObject
from .domain import vmmInspectionData
class vmmInspection(vmmGObject):
# Can't find a way to make Thread release our reference
_leak_check = False
def __init__(self):
vmmGObject.__init__(self)
self._thread = Thread(name="inspection thread", target=self._run)
self._thread.daemon = True
self._wait = 5 * 1000 # 5 seconds
self._q = Queue()
self._conns = {}
self._vmseen = {}
self._cached_data = {}
def _cleanup(self):
self._thread = None
self._q = Queue()
self._conns = {}
self._vmseen = {}
self._cached_data = {}
# Called by the main thread whenever a connection is added or
# removed. We tell the inspection thread, so it can track
# connections.
def conn_added(self, engine_ignore, conn):
obj = ("conn_added", conn)
self._q.put(obj)
def conn_removed(self, engine_ignore, uri):
obj = ("conn_removed", uri)
self._q.put(obj)
# Called by the main thread whenever a VM is added to vmlist.
def vm_added(self, conn, connkey):
if connkey.startswith("guestfs-"):
logging.debug("ignore libvirt/guestfs temporary VM %s",
connkey)
return
obj = ("vm_added", conn.get_uri(), connkey)
self._q.put(obj)
def vm_refresh(self, vm):
obj = ("vm_refresh", vm.conn.get_uri(), vm.get_name(), vm.get_uuid())
self._q.put(obj)
def start(self):
# Wait a few seconds before we do anything. This prevents
# inspection from being a burden for initial virt-manager
# interactivity (although it shouldn't affect interactivity at
# all).
def cb():
self._thread.start()
return 0
logging.debug("waiting")
self.timeout_add(self._wait, cb)
def _run(self):
# Process everything on the queue. If the queue is empty when
# called, block.
while True:
obj = self._q.get()
self._process_queue_item(obj)
self._q.task_done()
def _process_queue_item(self, obj):
if obj[0] == "conn_added":
conn = obj[1]
uri = conn.get_uri()
if conn and not (conn.is_remote()) and not (uri in self._conns):
self._conns[uri] = conn
conn.connect("vm-added", self.vm_added)
# No need to push the VMs of the newly added
# connection manually into the queue, as the above
# connect() will emit vm-added signals for all of
# its VMs.
elif obj[0] == "conn_removed":
uri = obj[1]
del self._conns[uri]
elif obj[0] == "vm_added" or obj[0] == "vm_refresh":
uri = obj[1]
if not (uri in self._conns):
# This connection disappeared in the meanwhile.
return
conn = self._conns[uri]
if not conn.is_active():
return
connkey = obj[2]
vm = conn.get_vm(connkey)
if not vm:
# The VM was removed in the meanwhile.
return
if obj[0] == "vm_refresh":
vmuuid = obj[3]
# When refreshing the inspection data of a VM,
# all we need is to remove it from the "seen" cache,
# as the data itself will be replaced once the new
# results are available.
del self._vmseen[vmuuid]
self._process_vm(conn, vm)
# Try processing a single VM, keeping into account whether it was
# visited already, and whether there are cached data for it.
def _process_vm(self, conn, vm):
def set_inspection_error(vm):
data = vmmInspectionData()
data.error = True
self._set_vm_inspection_data(vm, data)
vmuuid = vm.get_uuid()
prettyvm = vmuuid
try:
prettyvm = conn.get_uri() + ":" + vm.get_name()
if vmuuid in self._vmseen:
data = self._cached_data.get(vmuuid)
if not data:
return
if vm.inspection != data:
logging.debug("Found cached data for %s", prettyvm)
self._set_vm_inspection_data(vm, data)
return
# Whether success or failure, we've "seen" this VM now.
self._vmseen[vmuuid] = True
try:
data = self._inspect_vm(conn, vm)
if data:
self._set_vm_inspection_data(vm, data)
else:
set_inspection_error(vm)
except Exception:
set_inspection_error(vm)
raise
except Exception:
logging.exception("%s: exception while processing", prettyvm)
def _inspect_vm(self, conn, vm):
g = GuestFS(close_on_exit=False)
prettyvm = conn.get_uri() + ":" + vm.get_name()
g.add_libvirt_dom(vm.get_backend(), readonly=1)
g.launch()
# Inspect the operating system.
roots = g.inspect_os()
if len(roots) == 0:
logging.debug("%s: no operating systems found", prettyvm)
return None
# Arbitrarily pick the first root device.
root = roots[0]
# Inspection results.
os_type = g.inspect_get_type(root) # eg. "linux"
distro = g.inspect_get_distro(root) # eg. "fedora"
major_version = g.inspect_get_major_version(root) # eg. 14
minor_version = g.inspect_get_minor_version(root) # eg. 0
hostname = g.inspect_get_hostname(root) # string
product_name = g.inspect_get_product_name(root) # string
product_variant = g.inspect_get_product_variant(root) # string
# For inspect_list_applications and inspect_get_icon we
# require that the guest filesystems are mounted. However
# don't fail if this is not possible (I'm looking at you,
# FreeBSD).
filesystems_mounted = False
try:
# Mount up the disks, like guestfish --ro -i.
# Sort keys by length, shortest first, so that we end up
# mounting the filesystems in the correct order.
mps = list(g.inspect_get_mountpoints(root))
def compare(a, b):
if len(a[0]) > len(b[0]):
return 1
elif len(a[0]) == len(b[0]):
return 0
else:
return -1
mps.sort(compare)
for mp_dev in mps:
try:
g.mount_ro(mp_dev[1], mp_dev[0])
except Exception:
logging.exception("%s: exception mounting %s on %s "
"(ignored)",
prettyvm, mp_dev[1], mp_dev[0])
filesystems_mounted = True
except Exception:
logging.exception("%s: exception while mounting disks (ignored)",
prettyvm)
icon = None
apps = None
if filesystems_mounted:
# string containing PNG data
icon = g.inspect_get_icon(root, favicon=0, highquality=1)
if icon == "" or icon is None:
# no high quality icon, try a low quality one
icon = g.inspect_get_icon(root, favicon=0, highquality=0)
if icon == "":
icon = None
# Inspection applications.
apps = g.inspect_list_applications(root)
# Force the libguestfs handle to close right now.
del g
# Log what we found.
logging.debug("%s: detected operating system: %s %s %d.%d (%s)",
prettyvm, os_type, distro, major_version, minor_version,
product_name)
logging.debug("hostname: %s", hostname)
if icon:
logging.debug("icon: %d bytes", len(icon))
if apps:
logging.debug("# apps: %d", len(apps))
data = vmmInspectionData()
data.os_type = str(os_type)
data.distro = str(distro)
data.major_version = int(major_version)
data.minor_version = int(minor_version)
data.hostname = str(hostname)
data.product_name = str(product_name)
data.product_variant = str(product_variant)
data.icon = icon
data.applications = list(apps)
data.error = False
return data
def _set_vm_inspection_data(self, vm, data):
vm.inspection = data
vm.inspection_data_updated()
self._cached_data[vm.get_uuid()] = data