agent-desktop/tests/e2e/interaction_lock.py
Lahfir 4add46ab38 chore: checkpoint five verified remediation rounds before e2e convergence
Freezes the working tree as a fixed baseline: static gates green (1551 lib
tests, clippy -D warnings, fmt, release 0.4.7), live-verified E1/E2 fixes,
notification/harness work pending e2e acceptance. Known-open: hover fixture
churn to back out, 3 e2e failures (hover oracle, AE6 sheet, sheet cancel),
NT1-NT4 unproven.
2026-07-11 22:06:13 -07:00

89 lines
2.7 KiB
Python

#!/usr/bin/env python3
import fcntl
import os
import stat
import subprocess
import sys
LEASE_FD_ENV = "AGENT_DESKTOP_INTERACTION_LEASE_FD"
def canonical_lock_path(root="/tmp"):
directory = os.path.join(root, f"agent-desktop-{os.geteuid()}")
return directory, os.path.join(directory, "interaction.lock")
def _prepare_directory(directory):
try:
os.mkdir(directory, 0o700)
except FileExistsError:
pass
metadata = os.lstat(directory)
if not stat.S_ISDIR(metadata.st_mode) or stat.S_ISLNK(metadata.st_mode):
raise RuntimeError("interaction lease parent is not a real directory")
if metadata.st_uid != os.geteuid():
raise RuntimeError("interaction lease parent is not owned by this user")
os.chmod(directory, 0o700)
def acquire(root="/tmp"):
directory, path = canonical_lock_path(root)
_prepare_directory(directory)
flags = os.O_RDWR | os.O_CREAT
if hasattr(os, "O_NOFOLLOW"):
flags |= os.O_NOFOLLOW
fd = os.open(path, flags, 0o600)
metadata = os.fstat(fd)
if not stat.S_ISREG(metadata.st_mode) or metadata.st_uid != os.geteuid():
os.close(fd)
raise RuntimeError("interaction lease is not a private user-owned regular file")
if metadata.st_nlink != 1:
os.close(fd)
raise RuntimeError("interaction lease has an unexpected link count")
os.fchmod(fd, 0o600)
try:
fcntl.flock(fd, fcntl.LOCK_EX | fcntl.LOCK_NB)
except BlockingIOError:
os.close(fd)
return None
os.set_inheritable(fd, True)
return fd
def verify_inherited(raw_fd):
fd = int(raw_fd)
if fd < 0:
raise ValueError("interaction lease FD must be nonnegative")
metadata = os.fstat(fd)
_, path = canonical_lock_path()
canonical = os.stat(path, follow_symlinks=False)
if (metadata.st_dev, metadata.st_ino) != (canonical.st_dev, canonical.st_ino):
raise RuntimeError("interaction lease FD does not identify the canonical lock")
return fd
def run(command):
fd = acquire()
if fd is None:
print("SKIP (blocked): canonical desktop interaction lease is held", file=sys.stderr)
return 2
try:
environment = os.environ.copy()
environment[LEASE_FD_ENV] = str(fd)
return subprocess.run(command, env=environment, pass_fds=(fd,), check=False).returncode
finally:
os.close(fd)
def main():
if len(sys.argv) >= 3 and sys.argv[1] == "run":
raise SystemExit(run(sys.argv[2:]))
if len(sys.argv) == 3 and sys.argv[1] == "verify":
verify_inherited(sys.argv[2])
return
raise SystemExit("usage: interaction_lock.py run COMMAND... | verify FD")
if __name__ == "__main__":
main()