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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
119 # Since python 3.13 we cannot use addfile() to create the member header.
120 # Add the tarinfo directly using public but undocumented attributes.
121
122 buf = disk.tobuf(tar.format, tar.encoding, tar.errors)
123 tar.fileobj.write(buf)
124 tar.members.append(disk)
125
126 # Update the offset and position to the location of the next member.
127
128 tar.offset = offset + (disk.size + 511) & ~511
129 tar.fileobj.seek(tar.offset)
130
131 # 6. Shrink the tar to the actual size.
132
133 tar.fileobj.truncate(tar.offset)
134
135 with tarfile.open(tar_file) as tar:
136 members = [{"name": m.name, "size": m.size, "offset": m.offset_data}
137 for m in tar]
138 iotests.log("=== OVA file contents ===")
139 iotests.log(members)