def _prepare_guest_kernel_and_ramdisk(config):
"""
Use PyGrub to extract the kernel and ramdisk from the given disk image.
"""
disk_image = config.getConfigItem(DomainConfig.DISK_IMAGE_PATH)
# Use pygrub to extract the initrd and the kernel from the disk image.
(status, output) = \
commands.getstatusoutput("%s -q %s" % (PYGRUB, disk_image))
if status != 0:
raise VirtualizationException(
"Error occurred while executing '%s' (status=%d). Output=%s" %
(PYGRUB, status, output))
# Now analyze the output and extract the names of the new kernel and initrd
# images from it.
(pygrub_kernel_path, pygrub_initrd_path) = \
_extract_image_paths_from_pygrub_output(output)
# Rename the extracted images to the names we are pointing to in the
# configuration file.
runtime_kernel_path = config.getConfigItem(DomainConfig.KERNEL_PATH)
runtime_initrd_path = config.getConfigItem(DomainConfig.RAMDISK_PATH)
try:
os.rename(pygrub_kernel_path, runtime_kernel_path)
os.rename(pygrub_initrd_path, runtime_initrd_path)
except OSError:
oe = sys.exc_info()[1]
raise_with_tb(
VirtualizationException(
"Error occurred while renaming runtime image paths: %s" %
str(oe)),
sys.exc_info()[2])
def _connect_to_hypervisor():
"""Connect to the hypervisor."""
# First, attempt to import libvirt. If we don't have that, we can't do
# much else.
try:
import libvirt
except ImportError as ie:
raise VirtualizationException("Unable to locate libvirt: %s" % str(ie))
# Attempt to connect to the hypervisor.
try:
connection = libvirt.open(None)
except Exception as e:
raise VirtualizationException("Could not connect to hypervisor: %s" % str(e))
return connection
def start_domain(uuid):
"""
Boots the domain for the first time after installation is complete.
"""
# Load the configuration file for this UUID.
domain = DomainDirectory()
config = domain.load_config(uuid)
# Connect to the hypervisor.
connection = libvirt.open(None)
# We will attempt to determine if the domain is configured to use a
# bootloader. If not, we'll have to explicitly use the kernel and initrd
# data provided in the config to start the domain.
try:
config.getConfigItem(DomainConfig.BOOTLOADER)
except DomainConfigError:
dce = sys.exc_info()[1]
# No bootloader tag present. Use pygrub to extract the kernel from
# the disk image if its Xen. For fully virt we dont have pygrub, it
# directly emulates the BIOS loading the first sector of the boot disk.
if connection.getType() == 'Xen':
# This uses pygrub which comes only with xen
_prepare_guest_kernel_and_ramdisk(config)
# Now, we'll restart the instance, this time using the re-create XML.
try:
domain = connection.createLinux(config.toXML(), 0)
except Exception:
e = sys.exc_info()[1]
raise_with_tb(
VirtualizationException(
"Error occurred while attempting to recreate domain %s: %s" %
(uuid, str(e))),
sys.exc_info()[2])
def _call_domain_control_routine(uuid, routine_name, *args):
"""
Call a function in a domain, optionally with a set of arguments.
"""
# If libvirt is not available, this is a no-op.
if not libvirt: return
# Lookup the domain by its UUID.
(conn, domain) = _get_domain(uuid)
# Get a reference to the domain's control routine.
ctrl_func = None
try:
ctrl_func = getattr(domain, routine_name)
except AttributeError:
raise_with_tb(
VirtualizationException("Unknown function: %s" % routine_name),
sys.exc_info()[2])
result = 0
try:
if sys.version_info[0] == 3:
result = ctrl_func(*args)
else:
result = apply(ctrl_func, args)
except TypeError:
te = sys.exc_info()[1]
raise_with_tb(
VirtualizationException("Invalid arguments (%s) to %s: %s" %
(str(args), routine_name, str(te))),
sys.exc_info()[2])
except libvirt.libvirtError:
le = sys.exc_info()[1]
raise_with_tb(
VirtualizationException("LibVirt Error %s: %s" %
(routine_name, str(le))),
sys.exc_info()[2])
# Handle the return code. Anything non-zero is an error.
if result != 0:
raise_with_tb(
VirtualizationException(
"Could not perform function '%s' on domain %s. Error: %s" %
(routine_name, uuid, str(result))),
sys.exc_info()[2])
def save_unknown_domain_configs(self, domain_uuids):
"""
This function saves the configuration for any domains whose UUIDs are
passed in the domain_uuids list. If the UUID is already known, it is
skipped.
"""
for uuid in domain_uuids:
uuid = sstr(uuid)
# If we already have a config for this uuid, skip it. Also, don't
# try to figure out a config for a host UUID.
if not is_host_uuid(uuid) and not self.is_known_config(uuid):
# The UUID is a formatted string. Turn it back into a number,
# since that's what libvirt wants.
dehyphenized_uuid = dehyphenize_uuid(uuid)
uuid_as_num = binascii.unhexlify(dehyphenized_uuid)
# Lookup the domain by its uuid.
try:
domain = self.conn.lookupByUUID(uuid_as_num)
except libvirt.libvirtError:
lve = sys.exc_info()[1]
raise VirtualizationException(
"Failed to obtain handle to domain %s: %s" %
(uuid, repr(lve)))
# Now grab the XML description of the configuration.
xml = domain.XMLDesc(0)
# Write the xml out to a file so that we can load it into our
# abstract DomainConfig object and manipulate it easily.
cfg_file_path = self.__write_xml_file(uuid, xml)
new_config = DomainConfig(self.__path, uuid)
# Don't record the config this time if the domain is
# installing; we don't want to restart the domain later and
# make it re-install itself.
if not new_config.isInstallerConfig():
# Now we'll reformat the configuration object so that it's
# valid the next time this domain runs..
self.__fixup_config_for_restart(new_config)
# The config is now prepared. Save it and move on to the
# next uuid.
new_config.save()
else:
# Remove the config file we just wrote.
os.unlink(cfg_file_path)
def _get_domain(uuid):
"""
Lookup the domain by its UUID. If not found, raise an exception.
"""
conn = libvirt.open(None)
domain = None
hyphenized_uuid = hyphenize_uuid(uuid)
try:
domain = conn.lookupByUUIDString(hyphenized_uuid)
except libvirt.libvirtError:
lve = sys.exc_info()[1]
raise_with_tb(VirtualizationException("Domain UUID '%s' not found: %s" % (hyphenized_uuid, str(lve))),
sys.exc_info()[2])
return (conn, domain)
def _extract_image_paths_from_pygrub_output(output):
"""
Searches for the paths of the kernel and initrd files in the output of
pygrub. If not found, a VirtualizationException is raised. Otherwise,
the (kernel_path, initrd_path) tuple is returned.
"""
match = re.search("^linux \(kernel (\S+)\)\(ramdisk (\S+)\)", output,
re.MULTILINE)
if match is None or len(match.groups()) != 2:
raise VirtualizationException(
"Could not locate kernel and initrd in pygrub output: %s" % output)
kernel_path = match.group(1)
initrd_path = match.group(2)
return (kernel_path, initrd_path)
def poll_state(uuid):
"""
Polls just the state of the guest with the provided UUID. This state is
returned.
"""
conn = libvirt.openReadOnly(None)
if not conn:
raise VirtualizationException("Failed to open connection to hypervisor.")
# Attempt to connect to the domain. Since there is technically no
# "stopped" state, we will assume that if we cannot connect the domain is
# not running. Unfortunately, we can't really determine if the domain
# actually exists.
domain = None
try:
domain = conn.lookupByUUIDString(hyphenize_uuid(uuid))
except libvirt.libvirtError:
# Can't find domain. Return stopped state.
return State(None)
# Now that we have the domain, lookup the state.
domain_info = domain.info()
return State(VIRT_STATE_NAME_MAP[domain_info[0]])
def __init__(self):
self.__path = CONFIG_DIR
self.conn = libvirt.openReadOnly(None)
if not self.conn:
raise VirtualizationException(
"Failed to open connection to hypervisor.")
def poll_hypervisor():
"""
This function polls the hypervisor for information about the currently
running set of domains. It returns a dictionary object that looks like the
following:
{ uuid : { 'name' : '...',
'uuid' : '...',
'virt_type' : '...',
'memory_size' : '...',
'vcpus' : '...',
'state' : '...' }, ... }
"""
if not libvirt:
return {}
try:
conn = libvirt.openReadOnly(None)
except libvirt.libvirtError:
# virConnectOpen() failed
sys.stderr.write(rhncli.utf8_encode(_("Warning: Could not retrieve virtualization information!\n\t" +
"libvirtd service needs to be running.\n")))
conn = None
if not conn:
# No connection to hypervisor made
return {}
domainIDs = conn.listDomainsID()
state = {}
for domainID in domainIDs:
try:
domain = conn.lookupByID(domainID)
except libvirt.libvirtError:
lve = sys.exc_info()[1]
raise_with_tb(VirtualizationException("Failed to obtain handle to domain %d: %s" % (domainID, repr(lve)),
sys.exc_info()[2]))
uuid = binascii.hexlify(domain.UUID())
# SEE: http://libvirt.org/html/libvirt-libvirt.html#virDomainInfo
# for more info.
domain_info = domain.info()
# Set the virtualization type. We can tell if the domain is fully virt
# by checking the domain's OSType() attribute.
virt_type = VirtualizationType.PARA
if is_fully_virt(domain):
virt_type = VirtualizationType.FULLY
# we need to filter out the small per/minute KB changes
# that occur inside a vm. To do this we divide by 1024 to
# drop our precision down to megabytes with an int then
# back up to KB
memory = int(domain_info[2] / 1024);
memory = memory * 1024;
properties = {
PropertyType.NAME : domain.name(),
PropertyType.UUID : uuid,
PropertyType.TYPE : virt_type,
PropertyType.MEMORY : str(memory), # current memory
PropertyType.VCPUS : domain_info[3],
PropertyType.STATE : VIRT_STATE_NAME_MAP[domain_info[0]] }
state[uuid] = properties
if state: _log_debug("Polled state: %s" % repr(state))
return state
