LXR qemu/tests/qemu-iotests/302

   1#!/usr/bin/env python3
   2# group: quick
   3#
   4# Tests converting qcow2 compressed to NBD
   5#
   6# Copyright (c) 2020 Nir Soffer <nirsof@gmail.com>
   7#
   8# This program is free software; you can redistribute it and/or modify
   9# it under the terms of the GNU General Public License as published by
  10# the Free Software Foundation; either version 2 of the License, or
  11# (at your option) any later version.
  12#
  13# This program is distributed in the hope that it will be useful,
  14# but WITHOUT ANY WARRANTY; without even the implied warranty of
  15# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16# GNU General Public License for more details.
  17#
  18# You should have received a copy of the GNU General Public License
  19# along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20#
  21# owner=nirsof@gmail.com
  22
  23import io
  24import tarfile
  25
  26import iotests
  27
  28from iotests import (
  29    file_path,
  30    qemu_img,
  31    qemu_img_check,
  32    qemu_img_create,
  33    qemu_img_log,
  34    qemu_img_measure,
  35    qemu_io,
  36    qemu_nbd_popen,
  37)
  38
  39iotests.script_initialize(supported_fmts=["qcow2"])
  40
  41# Create source disk. Using qcow2 to enable strict comparing later, and
  42# avoid issues with random filesystem on CI environment.
  43src_disk = file_path("disk.qcow2")
  44qemu_img_create("-f", iotests.imgfmt, src_disk, "1g")
  45qemu_io("-f", iotests.imgfmt, "-c", "write 1m 64k", src_disk)
  46
  47# The use case is writing qcow2 image directly into an ova file, which
  48# is a tar file with specific layout. This is tricky since we don't know the
  49# size of the image before compressing, so we have to do:
  50# 1. Add an ovf file.
  51# 2. Find the offset of the next member data.
  52# 3. Make room for image data, allocating for the worst case.
  53# 4. Write compressed image data into the tar.
  54# 5. Add a tar entry with the actual image size.
  55# 6. Shrink the tar to the actual size, aligned to 512 bytes.
  56
  57tar_file = file_path("test.ova")
  58
  59with tarfile.open(tar_file, "w") as tar:
  60
  61    # 1. Add an ovf file.
  62
  63    ovf_data = b"<xml/>"
  64    ovf = tarfile.TarInfo("vm.ovf")
  65    ovf.size = len(ovf_data)
  66    tar.addfile(ovf, io.BytesIO(ovf_data))
  67
  68    # 2. Find the offset of the next member data.
  69
  70    offset = tar.fileobj.tell() + 512
  71
  72    # 3. Make room for image data, allocating for the worst case.
  73
  74    measure = qemu_img_measure("-O", "qcow2", src_disk)
  75    tar.fileobj.truncate(offset + measure["required"])
  76
  77    # 4. Write compressed image data into the tar.
  78
  79    nbd_sock = file_path("nbd-sock", base_dir=iotests.sock_dir)
  80    nbd_uri = "nbd+unix:///exp?socket=" + nbd_sock
  81
  82    # Use raw format to allow creating qcow2 directly into tar file.
  83    with qemu_nbd_popen(
  84            "--socket", nbd_sock,
  85            "--export-name", "exp",
  86            "--format", "raw",
  87            "--offset", str(offset),
  88            tar_file):
  89
  90        iotests.log("=== Target image info ===")
  91        qemu_img_log("info", nbd_uri)
  92
  93        qemu_img(
  94            "convert",
  95            "-f", iotests.imgfmt,
  96            "-O", "qcow2",
  97            "-c",
  98            src_disk,
  99            nbd_uri)
 100
 101        iotests.log("=== Converted image info ===")
 102        qemu_img_log("info", nbd_uri)
 103
 104        iotests.log("=== Converted image check ===")
 105        qemu_img_log("check", nbd_uri)
 106
 107        iotests.log("=== Comparing to source disk ===")
 108        qemu_img_log("compare", src_disk, nbd_uri)
 109
 110        actual_size = qemu_img_check(nbd_uri)["image-end-offset"]
 111
 112    # 5. Add a tar entry with the actual image size.
 113
 114    disk = tarfile.TarInfo("disk")
 115    disk.size = actual_size
 116    tar.addfile(disk)
 117
 118    # 6. Shrink the tar to the actual size, aligned to 512 bytes.
 119
 120    tar_size = offset + (disk.size + 511) & ~511
 121    tar.fileobj.seek(tar_size)
 122    tar.fileobj.truncate(tar_size)
 123
 124with tarfile.open(tar_file) as tar:
 125    members = [{"name": m.name, "size": m.size, "offset": m.offset_data}
 126               for m in tar]
 127    iotests.log("=== OVA file contents ===")
 128    iotests.log(members)
 129