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Create a kpartx_disk_img function

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So that it can be used in tests as well as in imgutils

(cherry picked from commit d69f01d4a8)
This commit is contained in:
Brian C. Lane 2018-11-08 15:47:53 -08:00
parent e7310c7260
commit faad43ced8
1 changed files with 27 additions and 15 deletions
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42
src/pylorax/imgutils.py
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@ -1,6 +1,6 @@
# imgutils.py - utility functions/classes for building disk images
#
# Copyright (C) 2011-2015 Red Hat, Inc.
# Copyright (C) 2011-2018 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
@ -356,6 +356,31 @@ class Mount(object):
def __exit__(self, exc_type, exc_value, tracebk):
umount(self.mnt)
def kpartx_disk_img(disk_img):
"""Attach a disk image's partitions to /dev/loopX using kpartx
:param disk_img: The full path to a partitioned disk image
:type disk_img: str
:returns: list of (loopXpN, size)
:rtype: list of tuples
"""
# Example kpartx output
# kpartx -p p -v -a /tmp/diskV2DiCW.im
# add map loop2p1 (253:2): 0 3481600 linear /dev/loop2 2048
# add map loop2p2 (253:3): 0 614400 linear /dev/loop2 3483648
kpartx_output = runcmd_output(["kpartx", "-v", "-a", "-s", disk_img])
logger.debug(kpartx_output)
# list of (deviceName, sizeInBytes)
loop_devices = []
for line in kpartx_output.splitlines():
# add map loop2p3 (253:4): 0 7139328 linear /dev/loop2 528384
# 3rd element is size in 512 byte blocks
if line.startswith("add map "):
fields = line[8:].split()
loop_devices.append( (fields[0], int(fields[3])*512) )
return loop_devices
class PartitionMount(object):
""" Mount a partitioned image file using kpartx """
def __init__(self, disk_img, mount_ok=None, submount=None):
@ -387,21 +412,8 @@ class PartitionMount(object):
if not self.mount_ok:
self.mount_ok = lambda mount_dir: os.path.isfile(mount_dir+"/etc/passwd")
# Example kpartx output
# kpartx -p p -v -a /tmp/diskV2DiCW.im
# add map loop2p1 (253:2): 0 3481600 linear /dev/loop2 2048
# add map loop2p2 (253:3): 0 614400 linear /dev/loop2 3483648
kpartx_output = runcmd_output(["kpartx", "-v", "-a", "-s", self.disk_img])
logger.debug(kpartx_output)
# list of (deviceName, sizeInBytes)
self.loop_devices = []
for line in kpartx_output.splitlines():
# add map loop2p3 (253:4): 0 7139328 linear /dev/loop2 528384
# 3rd element is size in 512 byte blocks
if line.startswith("add map "):
fields = line[8:].split()
self.loop_devices.append( (fields[0], int(fields[3])*512) )
self.loop_devices = kpartx_disk_img(self.disk_img)
def __enter__(self):
# Mount the device selected by mount_ok, if possible