#!/usr/bin/env python3
#
# Tests converting qcow2 compressed to NBD
#
# Copyright (c) 2020 Nir Soffer <nirsof@gmail.com>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
#
# owner=nirsof@gmail.com
import io
import tarfile
import iotests
from iotests import (
file_path,
qemu_img,
qemu_img_check,
qemu_img_create,
qemu_img_log,
qemu_img_measure,
qemu_io,
qemu_nbd_popen,
)
iotests.script_initialize(supported_fmts=["qcow2"])
# Create source disk. Using qcow2 to enable strict comparing later, and
# avoid issues with random filesystem on CI environment.
src_disk = file_path("disk.qcow2")
qemu_img_create("-f", iotests.imgfmt, src_disk, "1g")
qemu_io("-f", iotests.imgfmt, "-c", "write 1m 64k", src_disk)
# The use case is writing qcow2 image directly into an ova file, which
# is a tar file with specific layout. This is tricky since we don't know the
# size of the image before compressing, so we have to do:
# 1. Add an ovf file.
# 2. Find the offset of the next member data.
# 3. Make room for image data, allocating for the worst case.
# 4. Write compressed image data into the tar.
# 5. Add a tar entry with the actual image size.
# 6. Shrink the tar to the actual size, aligned to 512 bytes.
tar_file = file_path("test.ova")
with tarfile.open(tar_file, "w") as tar:
# 1. Add an ovf file.
ovf_data = b"<xml/>"
ovf = tarfile.TarInfo("vm.ovf")
ovf.size = len(ovf_data)
tar.addfile(ovf, io.BytesIO(ovf_data))
# 2. Find the offset of the next member data.
offset = tar.fileobj.tell() + 512
# 3. Make room for image data, allocating for the worst case.
measure = qemu_img_measure("-O", "qcow2", src_disk)
tar.fileobj.truncate(offset + measure["required"])
# 4. Write compressed image data into the tar.
nbd_sock = file_path("nbd-sock", base_dir=iotests.sock_dir)
nbd_uri = "nbd+unix:///exp?socket=" + nbd_sock
# Use raw format to allow creating qcow2 directly into tar file.
with qemu_nbd_popen(
"--socket", nbd_sock,
"--export-name", "exp",
"--format", "raw",
"--offset", str(offset),
tar_file):
iotests.log("=== Target image info ===")
qemu_img_log("info", nbd_uri)
qemu_img(
"convert",
"-f", iotests.imgfmt,
"-O", "qcow2",
"-c",
src_disk,
nbd_uri)
iotests.log("=== Converted image info ===")
qemu_img_log("info", nbd_uri)
iotests.log("=== Converted image check ===")
qemu_img_log("check", nbd_uri)
iotests.log("=== Comparing to source disk ===")
qemu_img_log("compare", src_disk, nbd_uri)
actual_size = qemu_img_check(nbd_uri)["image-end-offset"]
# 5. Add a tar entry with the actual image size.
disk = tarfile.TarInfo("disk")
disk.size = actual_size
tar.addfile(disk)
# 6. Shrink the tar to the actual size, aligned to 512 bytes.
tar_size = offset + (disk.size + 511) & ~511
tar.fileobj.seek(tar_size)
tar.fileobj.truncate(tar_size)
with tarfile.open(tar_file) as tar:
members = [{"name": m.name, "size": m.size, "offset": m.offset_data}
for m in tar]
iotests.log("=== OVA file contents ===")
iotests.log(members)
