88 lines
3.5 KiB
Python
Executable file
88 lines
3.5 KiB
Python
Executable file
#!/usr/bin/python3
|
|
|
|
import contextlib
|
|
import json
|
|
import math
|
|
import os
|
|
import subprocess
|
|
import sys
|
|
import tempfile
|
|
|
|
def tree_size(tree):
|
|
size = 0
|
|
for root, dirs, files in os.walk(tree):
|
|
for entry in files + dirs:
|
|
path = os.path.join(root, entry)
|
|
size += os.stat(path, follow_symlinks=False).st_size
|
|
return size
|
|
|
|
@contextlib.contextmanager
|
|
def mount(source, dest, *options):
|
|
os.makedirs(dest, 0o755, True)
|
|
subprocess.run(["mount", *options, source, dest], check=True)
|
|
try:
|
|
yield
|
|
finally:
|
|
subprocess.run(["umount", "-R", dest], check=True)
|
|
|
|
@contextlib.contextmanager
|
|
def mount_api(dest):
|
|
with mount("/dev", f"{dest}/dev", "-o", "rbind"), \
|
|
mount("/proc", f"{dest}/proc", "-o", "rbind"), \
|
|
mount("/sys", f"{dest}/sys", "-o", "rbind"), \
|
|
mount("none", f"{dest}/run", "-t", "tmpfs"):
|
|
yield
|
|
|
|
@contextlib.contextmanager
|
|
def loop_device(image, size, offset=0):
|
|
r = subprocess.run(["losetup", "--partscan", "--show", "--find", "--sizelimit", str(size), "--offset", str(offset),
|
|
image], stdout=subprocess.PIPE, encoding="utf-8", check=True)
|
|
loop = r.stdout.strip()
|
|
try:
|
|
yield loop
|
|
finally:
|
|
subprocess.run(["losetup", "-d", loop], check=True)
|
|
|
|
def main(tree, output_dir, options):
|
|
filename = options["filename"]
|
|
# partition_table_id = options["partition_table_id"]
|
|
root_fs_uuid = options["root_fs_uuid"]
|
|
|
|
# Create a working directory on a tmpfs, maybe we should implicitly
|
|
# always do this.
|
|
with tempfile.TemporaryDirectory() as workdir:
|
|
image = f"{workdir}/image.raw"
|
|
mountpoint = f"{workdir}/mnt"
|
|
|
|
# Create an empty image file of the right size
|
|
size = int(math.ceil(tree_size(tree) * 1.2 / 512) * 512)
|
|
subprocess.run(["truncate", "--size", str(size), image], check=True)
|
|
|
|
# Set up the partition table of the image
|
|
partition_table = "label: mbr\nlabel-id: {partition_table_id}\nbootable, type=83"
|
|
subprocess.run(["sfdisk", "-q", image], input=partition_table, encoding='utf-8', check=True)
|
|
r = subprocess.run(["sfdisk", "--json", image], stdout=subprocess.PIPE, encoding='utf-8', check=True)
|
|
partition_table = json.loads(r.stdout)
|
|
partition = partition_table["partitiontable"]["partitions"][0]
|
|
partition_offset = partition["start"] * 512
|
|
partition_size = partition["size"] * 512
|
|
|
|
# Populate the first partition of the image with an ext4 fs and fill it with the contents of the
|
|
# tree we are operating on.
|
|
subprocess.run(["mkfs.ext4", "-d", tree, "-U", root_fs_uuid, "-E", f"offset={partition_offset}", image,
|
|
f"{int(partition_size / 1024)}k"], input="y", encoding='utf-8', check=True)
|
|
|
|
# Mount the created image as a loopback device
|
|
with loop_device(image, size) as loop, \
|
|
mount(f"{loop}p1", mountpoint):
|
|
# Install grub2 into the boot sector of the image, and copy the grub2 imagise into /boot/grub2
|
|
with mount_api(mountpoint):
|
|
subprocess.run(["chroot", mountpoint, "grub2-install", "--no-floppy", "--target", "i386-pc", loop],
|
|
check=True)
|
|
|
|
subprocess.run(["qemu-img", "convert", "-O", "qcow2", "-c", image, f"{output_dir}/{filename}"], check=True)
|
|
|
|
if __name__ == '__main__':
|
|
args = json.load(sys.stdin)
|
|
ret = main(args["tree"], args["output_dir"], args["options"])
|
|
sys.exit(ret)
|