qemu

FORK: QEMU emulator
git clone https://git.neptards.moe/neptards/qemu.git
Log | Files | Refs | Submodules | LICENSE

302 (4000B)


      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 
     23 import io
     24 import tarfile
     25 
     26 import iotests
     27 
     28 from 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     img_info_log,
     38 )
     39 
     40 iotests.script_initialize(supported_fmts=["qcow2"])
     41 
     42 # Create source disk. Using qcow2 to enable strict comparing later, and
     43 # avoid issues with random filesystem on CI environment.
     44 src_disk = file_path("disk.qcow2")
     45 qemu_img_create("-f", iotests.imgfmt, src_disk, "1g")
     46 qemu_io("-f", iotests.imgfmt, "-c", "write 1m 64k", src_disk)
     47 
     48 # The use case is writing qcow2 image directly into an ova file, which
     49 # is a tar file with specific layout. This is tricky since we don't know the
     50 # size of the image before compressing, so we have to do:
     51 # 1. Add an ovf file.
     52 # 2. Find the offset of the next member data.
     53 # 3. Make room for image data, allocating for the worst case.
     54 # 4. Write compressed image data into the tar.
     55 # 5. Add a tar entry with the actual image size.
     56 # 6. Shrink the tar to the actual size, aligned to 512 bytes.
     57 
     58 tar_file = file_path("test.ova")
     59 
     60 with tarfile.open(tar_file, "w") as tar:
     61 
     62     # 1. Add an ovf file.
     63 
     64     ovf_data = b"<xml/>"
     65     ovf = tarfile.TarInfo("vm.ovf")
     66     ovf.size = len(ovf_data)
     67     tar.addfile(ovf, io.BytesIO(ovf_data))
     68 
     69     # 2. Find the offset of the next member data.
     70 
     71     offset = tar.fileobj.tell() + 512
     72 
     73     # 3. Make room for image data, allocating for the worst case.
     74 
     75     measure = qemu_img_measure("-O", "qcow2", src_disk)
     76     tar.fileobj.truncate(offset + measure["required"])
     77 
     78     # 4. Write compressed image data into the tar.
     79 
     80     nbd_sock = file_path("nbd-sock", base_dir=iotests.sock_dir)
     81     nbd_uri = "nbd+unix:///exp?socket=" + nbd_sock
     82 
     83     # Use raw format to allow creating qcow2 directly into tar file.
     84     with qemu_nbd_popen(
     85             "--socket", nbd_sock,
     86             "--export-name", "exp",
     87             "--format", "raw",
     88             "--offset", str(offset),
     89             tar_file):
     90 
     91         iotests.log("=== Target image info ===")
     92         # Not img_info_log as it enforces imgfmt, but now we print info on raw
     93         qemu_img_log("info", nbd_uri)
     94 
     95         qemu_img(
     96             "convert",
     97             "-f", iotests.imgfmt,
     98             "-O", "qcow2",
     99             "-c",
    100             src_disk,
    101             nbd_uri)
    102 
    103         iotests.log("=== Converted image info ===")
    104         img_info_log(nbd_uri)
    105 
    106         iotests.log("=== Converted image check ===")
    107         qemu_img_log("check", nbd_uri)
    108 
    109         iotests.log("=== Comparing to source disk ===")
    110         qemu_img_log("compare", src_disk, nbd_uri)
    111 
    112         actual_size = qemu_img_check(nbd_uri)["image-end-offset"]
    113 
    114     # 5. Add a tar entry with the actual image size.
    115 
    116     disk = tarfile.TarInfo("disk")
    117     disk.size = actual_size
    118     tar.addfile(disk)
    119 
    120     # 6. Shrink the tar to the actual size, aligned to 512 bytes.
    121 
    122     tar_size = offset + (disk.size + 511) & ~511
    123     tar.fileobj.seek(tar_size)
    124     tar.fileobj.truncate(tar_size)
    125 
    126 with tarfile.open(tar_file) as tar:
    127     members = [{"name": m.name, "size": m.size, "offset": m.offset_data}
    128                for m in tar]
    129     iotests.log("=== OVA file contents ===")
    130     iotests.log(members)