xref: /qemu/tests/qemu-iotests/302 (revision abff1abf) 
1#!/usr/bin/env python3
2#
3# Tests converting qcow2 compressed to NBD
4#
5# Copyright (c) 2020 Nir Soffer <nirsof@gmail.com>
6#
7# This program is free software; you can redistribute it and/or modify
8# it under the terms of the GNU General Public License as published by
9# the Free Software Foundation; either version 2 of the License, or
10# (at your option) any later version.
11#
12# This program is distributed in the hope that it will be useful,
13# but WITHOUT ANY WARRANTY; without even the implied warranty of
14# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15# GNU General Public License for more details.
16#
17# You should have received a copy of the GNU General Public License
18# along with this program.  If not, see <http://www.gnu.org/licenses/>.
19#
20# owner=nirsof@gmail.com
21
22import io
23import tarfile
24
25import iotests
26
27from iotests import (
28    file_path,
29    qemu_img,
30    qemu_img_check,
31    qemu_img_create,
32    qemu_img_log,
33    qemu_img_measure,
34    qemu_io,
35    qemu_nbd_popen,
36)
37
38iotests.script_initialize(supported_fmts=["qcow2"])
39
40# Create source disk. Using qcow2 to enable strict comparing later, and
41# avoid issues with random filesystem on CI environment.
42src_disk = file_path("disk.qcow2")
43qemu_img_create("-f", iotests.imgfmt, src_disk, "1g")
44qemu_io("-f", iotests.imgfmt, "-c", "write 1m 64k", src_disk)
45
46# The use case is writing qcow2 image directly into an ova file, which
47# is a tar file with specific layout. This is tricky since we don't know the
48# size of the image before compressing, so we have to do:
49# 1. Add an ovf file.
50# 2. Find the offset of the next member data.
51# 3. Make room for image data, allocating for the worst case.
52# 4. Write compressed image data into the tar.
53# 5. Add a tar entry with the actual image size.
54# 6. Shrink the tar to the actual size, aligned to 512 bytes.
55
56tar_file = file_path("test.ova")
57
58with tarfile.open(tar_file, "w") as tar:
59
60    # 1. Add an ovf file.
61
62    ovf_data = b"<xml/>"
63    ovf = tarfile.TarInfo("vm.ovf")
64    ovf.size = len(ovf_data)
65    tar.addfile(ovf, io.BytesIO(ovf_data))
66
67    # 2. Find the offset of the next member data.
68
69    offset = tar.fileobj.tell() + 512
70
71    # 3. Make room for image data, allocating for the worst case.
72
73    measure = qemu_img_measure("-O", "qcow2", src_disk)
74    tar.fileobj.truncate(offset + measure["required"])
75
76    # 4. Write compressed image data into the tar.
77
78    nbd_sock = file_path("nbd-sock", base_dir=iotests.sock_dir)
79    nbd_uri = "nbd+unix:///exp?socket=" + nbd_sock
80
81    # Use raw format to allow creating qcow2 directly into tar file.
82    with qemu_nbd_popen(
83            "--socket", nbd_sock,
84            "--export-name", "exp",
85            "--format", "raw",
86            "--offset", str(offset),
87            tar_file):
88
89        iotests.log("=== Target image info ===")
90        qemu_img_log("info", nbd_uri)
91
92        qemu_img(
93            "convert",
94            "-f", iotests.imgfmt,
95            "-O", "qcow2",
96            "-c",
97            src_disk,
98            nbd_uri)
99
100        iotests.log("=== Converted image info ===")
101        qemu_img_log("info", nbd_uri)
102
103        iotests.log("=== Converted image check ===")
104        qemu_img_log("check", nbd_uri)
105
106        iotests.log("=== Comparing to source disk ===")
107        qemu_img_log("compare", src_disk, nbd_uri)
108
109        actual_size = qemu_img_check(nbd_uri)["image-end-offset"]
110
111    # 5. Add a tar entry with the actual image size.
112
113    disk = tarfile.TarInfo("disk")
114    disk.size = actual_size
115    tar.addfile(disk)
116
117    # 6. Shrink the tar to the actual size, aligned to 512 bytes.
118
119    tar_size = offset + (disk.size + 511) & ~511
120    tar.fileobj.seek(tar_size)
121    tar.fileobj.truncate(tar_size)
122
123with tarfile.open(tar_file) as tar:
124    members = [{"name": m.name, "size": m.size, "offset": m.offset_data}
125               for m in tar]
126    iotests.log("=== OVA file contents ===")
127    iotests.log(members)
128