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