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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 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)