debian-forge/osbuild
Lars Karlitski f6023ed78b Bind-mount vfs directories for each stage
Many of the stages need it anyway.
2019-05-06 00:23:56 +02:00

91 lines
3 KiB
Python
Executable file

#!/usr/bin/python3
import argparse
import contextlib
import json
import os
import subprocess
import sys
import tempfile
RESET = "\033[0m"
BOLD = "\033[1m"
RED = "\033[31m"
@contextlib.contextmanager
def tmpfs(save=None):
"""A contextmanager that mounts a tmpfs and returns its location.
If `save` is given, it should contain the name of an .tar.gz archive to
which the contents of the tmpfs will be written.
"""
with tempfile.TemporaryDirectory(prefix="osbuild-tree-", dir=os.getcwd()) as path:
subprocess.run(["mount", "-t", "tmpfs", "tmpfs", path], check=True)
try:
yield path
if save:
print(f"Saving tree to {save}...")
subprocess.run(["tar", "-czf", save, "-C", path, "."], stdout=subprocess.DEVNULL, check=True)
finally:
subprocess.run(["umount", path], check=True)
def main(pipeline_path, from_archive, save):
with open(pipeline_path) as f:
pipeline = json.load(f)
with tmpfs(save) as tree:
if from_archive:
r = subprocess.run(["tar", "-xzf", from_archive, "-C", tree])
if r.returncode != 0:
return
for i, stage in enumerate(pipeline["stages"], start=1):
name = stage["name"]
options = stage.get("options", {})
options["tree"] = os.path.abspath(tree)
options_str = json.dumps(options, indent=2)
print()
print(f"{RESET}{BOLD}{i}. {name}{RESET} {options_str}")
print()
script = f"""
set -e
mount -t tmpfs tmpfs /tmp
mount -t tmpfs tmpfs /var/tmp
mkdir -p {tree}/dev {tree}/sys {tree}/proc
mount --bind /dev {tree}/dev
mount --bind /sys {tree}/sys
mount --bind /proc {tree}/proc
stages/{name}
"""
try:
subprocess.run(["unshare", "--pid", "--kill-child", "--mount", "sh", "-c", script],
input=options_str, encoding="utf-8", check=True)
except KeyboardInterrupt:
print()
print(f"{RESET}{BOLD}{RED}Aborted{RESET}")
return 130
except subprocess.CalledProcessError as error:
print()
print(f"{RESET}{BOLD}{RED}{name} failed with code {error.returncode}{RESET}")
return 1
if __name__ == "__main__":
parser = argparse.ArgumentParser(description="Build operating system images")
parser.add_argument("pipeline_path", metavar="PIPELINE",
help="json file containing the pipeline that should be built")
parser.add_argument("--save", metavar="ARCHIVE",
help="save the resulting tree to ARCHIVE")
parser.add_argument("--from", dest="from_archive", metavar="ARCHIVE",
help="initialize the tree from ARCHIVE")
args = parser.parse_args()
sys.exit(main(**vars(args)))