/usr/lib/python2.7/dist-packages/provisioningserver/boot/tftppath.py is in python-maas-provisioningserver 1.5.4+bzr2294-0ubuntu1.2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 | # Copyright 2012-2014 Canonical Ltd. This software is licensed under the
# GNU Affero General Public License version 3 (see the file LICENSE).
"""Construct TFTP paths for boot files."""
from __future__ import (
absolute_import,
print_function,
unicode_literals,
)
str = None
__metaclass__ = type
__all__ = [
'compose_image_path',
'drill_down',
'list_boot_images',
'list_subdirs',
'locate_tftp_path',
]
import errno
from itertools import chain
from logging import getLogger
import os.path
logger = getLogger(__name__)
def compose_image_path(arch, subarch, release, label):
"""Compose the TFTP path for a PXE kernel/initrd directory.
The path returned is relative to the TFTP root, as it would be
identified by clients on the network.
:param arch: Main machine architecture.
:param subarch: Sub-architecture, or "generic" if there is none.
:param release: Operating system release, e.g. "precise".
:param label: Release label, e.g. "release" or "alpha-2".
:return: Path for the corresponding image directory (containing a
kernel and initrd) as exposed over TFTP.
"""
# This is a TFTP path, not a local filesystem path, so hard-code the slash.
return '/'.join([arch, subarch, release, label])
def locate_tftp_path(path, tftproot):
"""Return the local filesystem path corresponding to `path`.
The return value gives the filesystem path where you'd have to put
a file if you wanted it made available over TFTP as `path`.
:param path: Path as used in the TFTP protocol for which you want the
local filesystem equivalent. Pass `None` to get the root of the TFTP
hierarchy.
:param tftproot: The TFTP root directory.
"""
if path is None:
return tftproot
return os.path.join(tftproot, path.lstrip('/'))
def is_visible_subdir(directory, subdir):
"""Is `subdir` a non-hidden sub-directory of `directory`?"""
if subdir.startswith('.'):
return False
else:
return os.path.isdir(os.path.join(directory, subdir))
def list_subdirs(directory):
"""Return a list of non-hidden directories in `directory`."""
return [
subdir
for subdir in os.listdir(directory)
if is_visible_subdir(directory, subdir)
]
def extend_path(directory, path):
"""Dig one directory level deeper on `os.path.join(directory, *path)`.
If `path` is a list of consecutive path elements drilling down from
`directory`, return a list of sub-directory paths leading one step
further down.
:param directory: Base directory that `path` is relative to.
:param path: A path to a subdirectory of `directory`, represented as
a list of path elements relative to `directory`.
:return: A list of paths that go one sub-directory level further
down from `path`.
"""
return [
path + [subdir]
for subdir in list_subdirs(os.path.join(directory, *path))]
def drill_down(directory, paths):
"""Find the extensions of `paths` one level deeper into the filesystem.
:param directory: Base directory that each path in `paths` is relative to.
:param paths: A list of "path lists." Each path list is a list of
path elements drilling down into the filesystem from `directory`.
:return: A list of paths, each of which drills one level deeper down into
the filesystem hierarchy than the originals in `paths`.
"""
return list(chain.from_iterable(
extend_path(directory, path) for path in paths))
def extract_image_params(path):
"""Represent a list of TFTP path elements as a list of boot-image dicts.
The path must consist of a full [architecture, subarchitecture, release]
that identify a kind of boot that we may need an image for.
"""
arch, subarch, release, label = path
# XXX: rvb 2014-03-24: The images import script currently imports all the
# images for the configured selections (where a selection is an
# arch/subarch/series/label combination). When the import script grows the
# ability to import the images for a particular purpose, we need to change
# this code to report what is actually present.
purposes = ['commissioning', 'install', 'xinstall']
return [
dict(
architecture=arch, subarchitecture=subarch,
release=release, label=label, purpose=purpose)
for purpose in purposes
]
def list_boot_images(tftproot):
"""List the available boot images.
:param tftproot: TFTP root directory.
:return: A list of dicts, describing boot images as consumed by the
`report_boot_images` API call.
"""
# The sub-directories directly under tftproot, if they contain
# images, represent architectures.
try:
potential_archs = list_subdirs(tftproot)
except OSError as exception:
if exception.errno == errno.ENOENT:
# Directory does not exist, so return empty list.
logger.warning("No boot images have been imported yet.")
return []
else:
# Other error. Propagate.
raise
# Starting point for iteration: paths that contain only the
# top-level subdirectory of tftproot, i.e. the architecture name.
paths = [[subdir] for subdir in potential_archs]
# Extend paths deeper into the filesystem, through the levels that
# represent sub-architecture, release, and label. Any directory
# that doesn't extend this deep isn't a boot image.
for level in ['subarch', 'release', 'label']:
paths = drill_down(tftproot, paths)
# Each path we find this way should be a boot image.
# This gets serialised to JSON, so we really have to return a list, not
# just any iterable.
return list(chain.from_iterable(
extract_image_params(path) for path in paths))
|