/usr/lib/python3/dist-packages/provisioningserver/boot/pxe.py is in python3-maas-provisioningserver 2.4.0~beta2-6865-gec43e47e6-0ubuntu1.
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# GNU Affero General Public License version 3 (see the file LICENSE).
"""PXE Boot Method"""
__all__ = [
'PXEBootMethod',
]
from itertools import repeat
import os
import re
import shutil
from provisioningserver.boot import (
BootMethod,
BytesReader,
get_parameters,
)
from provisioningserver.events import (
EVENT_TYPES,
try_send_rack_event,
)
from provisioningserver.logger import get_maas_logger
from provisioningserver.utils.fs import (
atomic_copy,
atomic_symlink,
)
import tempita
maaslog = get_maas_logger('pxe')
class ARP_HTYPE:
"""ARP Hardware Type codes."""
ETHERNET = 0x01
# PXELINUX represents a MAC address in IEEE 802 hyphen-separated
# format. See http://www.syslinux.org/wiki/index.php/PXELINUX.
re_mac_address_octet = r'[0-9a-f]{2}'
re_mac_address = re.compile(
"-".join(repeat(re_mac_address_octet, 6)))
# We assume that the ARP HTYPE (hardware type) that PXELINUX sends is
# always Ethernet.
re_config_file = r'''
# Optional leading slash(es).
^/*
pxelinux[.]cfg # PXELINUX expects this.
/
(?: # either a MAC
{htype:02x} # ARP HTYPE.
-
(?P<mac>{re_mac_address.pattern}) # Capture MAC.
| # or "default"
default
(?: # perhaps with specified arch, with a separator of either '-'
# or '.', since the spec was changed and both are unambiguous
[.-](?P<arch>\w+) # arch
(?:-(?P<subarch>\w+))? # optional subarch
)?
)
$
'''
re_config_file = re_config_file.format(
htype=ARP_HTYPE.ETHERNET, re_mac_address=re_mac_address)
re_config_file = re_config_file.encode("ascii")
re_config_file = re.compile(re_config_file, re.VERBOSE)
class PXEBootMethod(BootMethod):
name = 'pxe'
bios_boot_method = 'pxe'
template_subdir = 'pxe'
bootloader_arches = ['i386', 'amd64']
bootloader_path = 'pxelinux.0'
bootloader_files = [
'pxelinux.0',
'chain.c32',
'ifcpu64.c32',
'ldlinux.c32',
'libcom32.c32',
'libutil.c32',
]
arch_octet = '00:00'
def match_path(self, backend, path):
"""Checks path for the configuration file that needs to be
generated.
:param backend: requesting backend
:param path: requested path
:return: dict of match params from path, None if no match
"""
match = re_config_file.match(path)
if match is None:
return None
return get_parameters(match)
def get_reader(self, backend, kernel_params, **extra):
"""Render a configuration file as a unicode string.
:param backend: requesting backend
:param kernel_params: An instance of `KernelParameters`.
:param extra: Allow for other arguments. This is a safety valve;
parameters generated in another component (for example, see
`TFTPBackend.get_boot_method_reader`) won't cause this to break.
"""
template = self.get_template(
kernel_params.purpose, kernel_params.arch,
kernel_params.subarch)
kernel_params.mac = extra.get('mac', '')
namespace = self.compose_template_namespace(kernel_params)
# We are going to do 2 passes of tempita substitution because there
# may be things like kernel params which include variables that can
# only be populated at run time and thus contain variables themselves.
# For example, an OS may need a kernel parameter that points back to
# fs_host and the kernel parameter comes through as part of the simple
# stream.
step1 = template.substitute(namespace)
return BytesReader(tempita.Template(step1).substitute(namespace)
.encode("utf-8"))
def _link_simplestream_bootloaders(self, stream_path, destination):
super()._link_simplestream_bootloaders(stream_path, destination)
# MAAS only requires the bootloader_files listed above to boot.
# However some users may want to use extra PXE files in custom
# configs or for debug. PXELinux checks / and then /syslinux so
# create a symlink to the stream_path which contains all extra PXE
# files. This also ensures if upstream ever starts requiring more
# modules PXE will continue to work.
syslinux_dst = os.path.join(destination, 'syslinux')
atomic_symlink(stream_path, syslinux_dst)
def _find_and_copy_bootloaders(self, destination, log_missing=True):
boot_sources_base = os.path.realpath(os.path.join(destination, '..'))
default_search_path = os.path.join(boot_sources_base, 'current')
syslinux_search_path = os.path.join(default_search_path, 'syslinux')
# In addition to the default search path search the previous
# syslinux subdir as well. Previously MAAS didn't copy all of the
# files required for PXE into the root tftp path. Also search the
# paths the syslinux-common and pxelinux Ubuntu packages installs files
# to on Xenial.
search_paths = [
default_search_path,
syslinux_search_path,
'/usr/lib/PXELINUX',
'/usr/lib/syslinux/modules/bios',
]
files_found = []
for search_path in search_paths:
for bootloader_file in self.bootloader_files:
bootloader_src = os.path.join(search_path, bootloader_file)
bootloader_src = os.path.realpath(bootloader_src)
bootloader_dst = os.path.join(destination, bootloader_file)
if (
os.path.exists(bootloader_src) and
not os.path.exists(bootloader_dst)):
# If the file was found in a previous snapshot copy it as
# once we're done the previous snapshot will be deleted. If
# the file was found elsewhere on the filesystem create a
# symlink so we stay current with that source.
if boot_sources_base in bootloader_src:
atomic_copy(bootloader_src, bootloader_dst)
else:
atomic_symlink(bootloader_src, bootloader_dst)
files_found.append(bootloader_file)
missing_files = [
bootloader_file for bootloader_file in self.bootloader_files
if bootloader_file not in files_found
]
if missing_files != []:
files_are_missing = True
if log_missing:
err_msg = (
"Unable to find a copy of %s in the SimpleStream or in "
"the system search paths %s. The %s bootloader type may "
"not work." %
(', '.join(missing_files), ', '.join(search_paths),
self.name)
)
try_send_rack_event(EVENT_TYPES.RACK_IMPORT_ERROR, err_msg)
maaslog.error(err_msg)
else:
files_are_missing = False
syslinux_search_paths = [
syslinux_search_path,
'/usr/lib/syslinux/modules/bios',
]
for search_path in syslinux_search_paths:
if os.path.exists(search_path):
syslinux_src = os.path.realpath(search_path)
syslinux_dst = os.path.join(destination, 'syslinux')
if destination in os.path.realpath(syslinux_src):
shutil.copy(bootloader_src, bootloader_dst)
else:
atomic_symlink(syslinux_src, syslinux_dst)
break
return files_are_missing
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