depot/third_party/nixpkgs/nixos/lib/test-driver/test_driver/driver.py

280 lines
9.3 KiB
Python

import os
import re
import signal
import tempfile
import threading
from collections.abc import Callable, Iterator
from contextlib import AbstractContextManager, contextmanager
from pathlib import Path
from typing import Any
from test_driver.logger import AbstractLogger
from test_driver.machine import Machine, NixStartScript, retry
from test_driver.polling_condition import PollingCondition
from test_driver.vlan import VLan
SENTINEL = object()
def get_tmp_dir() -> Path:
"""Returns a temporary directory that is defined by TMPDIR, TEMP, TMP or CWD
Raises an exception in case the retrieved temporary directory is not writeable
See https://docs.python.org/3/library/tempfile.html#tempfile.gettempdir
"""
tmp_dir = Path(tempfile.gettempdir())
tmp_dir.mkdir(mode=0o700, exist_ok=True)
if not tmp_dir.is_dir():
raise NotADirectoryError(
f"The directory defined by TMPDIR, TEMP, TMP or CWD: {tmp_dir} is not a directory"
)
if not os.access(tmp_dir, os.W_OK):
raise PermissionError(
f"The directory defined by TMPDIR, TEMP, TMP, or CWD: {tmp_dir} is not writeable"
)
return tmp_dir
def pythonize_name(name: str) -> str:
return re.sub(r"^[^A-z_]|[^A-z0-9_]", "_", name)
class Driver:
"""A handle to the driver that sets up the environment
and runs the tests"""
tests: str
vlans: list[VLan]
machines: list[Machine]
polling_conditions: list[PollingCondition]
global_timeout: int
race_timer: threading.Timer
logger: AbstractLogger
def __init__(
self,
start_scripts: list[str],
vlans: list[int],
tests: str,
out_dir: Path,
logger: AbstractLogger,
keep_vm_state: bool = False,
global_timeout: int = 24 * 60 * 60 * 7,
):
self.tests = tests
self.out_dir = out_dir
self.global_timeout = global_timeout
self.race_timer = threading.Timer(global_timeout, self.terminate_test)
self.logger = logger
tmp_dir = get_tmp_dir()
with self.logger.nested("start all VLans"):
vlans = list(set(vlans))
self.vlans = [VLan(nr, tmp_dir, self.logger) for nr in vlans]
def cmd(scripts: list[str]) -> Iterator[NixStartScript]:
for s in scripts:
yield NixStartScript(s)
self.polling_conditions = []
self.machines = [
Machine(
start_command=cmd,
keep_vm_state=keep_vm_state,
name=cmd.machine_name,
tmp_dir=tmp_dir,
callbacks=[self.check_polling_conditions],
out_dir=self.out_dir,
logger=self.logger,
)
for cmd in cmd(start_scripts)
]
def __enter__(self) -> "Driver":
return self
def __exit__(self, *_: Any) -> None:
with self.logger.nested("cleanup"):
self.race_timer.cancel()
for machine in self.machines:
try:
machine.release()
except Exception as e:
self.logger.error(f"Error during cleanup of {machine.name}: {e}")
for vlan in self.vlans:
try:
vlan.stop()
except Exception as e:
self.logger.error(f"Error during cleanup of vlan{vlan.nr}: {e}")
def subtest(self, name: str) -> Iterator[None]:
"""Group logs under a given test name"""
with self.logger.subtest(name):
try:
yield
except Exception as e:
self.logger.error(f'Test "{name}" failed with error: "{e}"')
raise e
def test_symbols(self) -> dict[str, Any]:
@contextmanager
def subtest(name: str) -> Iterator[None]:
return self.subtest(name)
general_symbols = dict(
start_all=self.start_all,
test_script=self.test_script,
machines=self.machines,
vlans=self.vlans,
driver=self,
log=self.logger,
os=os,
create_machine=self.create_machine,
subtest=subtest,
run_tests=self.run_tests,
join_all=self.join_all,
retry=retry,
serial_stdout_off=self.serial_stdout_off,
serial_stdout_on=self.serial_stdout_on,
polling_condition=self.polling_condition,
Machine=Machine, # for typing
)
machine_symbols = {pythonize_name(m.name): m for m in self.machines}
# If there's exactly one machine, make it available under the name
# "machine", even if it's not called that.
if len(self.machines) == 1:
(machine_symbols["machine"],) = self.machines
vlan_symbols = {
f"vlan{v.nr}": self.vlans[idx] for idx, v in enumerate(self.vlans)
}
print(
"additionally exposed symbols:\n "
+ ", ".join(map(lambda m: m.name, self.machines))
+ ",\n "
+ ", ".join(map(lambda v: f"vlan{v.nr}", self.vlans))
+ ",\n "
+ ", ".join(list(general_symbols.keys()))
)
return {**general_symbols, **machine_symbols, **vlan_symbols}
def test_script(self) -> None:
"""Run the test script"""
with self.logger.nested("run the VM test script"):
symbols = self.test_symbols() # call eagerly
exec(self.tests, symbols, None)
def run_tests(self) -> None:
"""Run the test script (for non-interactive test runs)"""
self.logger.info(
f"Test will time out and terminate in {self.global_timeout} seconds"
)
self.race_timer.start()
self.test_script()
# TODO: Collect coverage data
for machine in self.machines:
if machine.is_up():
machine.execute("sync")
def start_all(self) -> None:
"""Start all machines"""
with self.logger.nested("start all VMs"):
for machine in self.machines:
machine.start()
def join_all(self) -> None:
"""Wait for all machines to shut down"""
with self.logger.nested("wait for all VMs to finish"):
for machine in self.machines:
machine.wait_for_shutdown()
self.race_timer.cancel()
def terminate_test(self) -> None:
# This will be usually running in another thread than
# the thread actually executing the test script.
with self.logger.nested("timeout reached; test terminating..."):
for machine in self.machines:
machine.release()
# As we cannot `sys.exit` from another thread
# We can at least force the main thread to get SIGTERM'ed.
# This will prevent any user who caught all the exceptions
# to swallow them and prevent itself from terminating.
os.kill(os.getpid(), signal.SIGTERM)
def create_machine(
self,
start_command: str,
*,
name: str | None = None,
keep_vm_state: bool = False,
) -> Machine:
tmp_dir = get_tmp_dir()
cmd = NixStartScript(start_command)
name = name or cmd.machine_name
return Machine(
tmp_dir=tmp_dir,
out_dir=self.out_dir,
start_command=cmd,
name=name,
keep_vm_state=keep_vm_state,
logger=self.logger,
)
def serial_stdout_on(self) -> None:
self.logger.print_serial_logs(True)
def serial_stdout_off(self) -> None:
self.logger.print_serial_logs(False)
def check_polling_conditions(self) -> None:
for condition in self.polling_conditions:
condition.maybe_raise()
def polling_condition(
self,
fun_: Callable | None = None,
*,
seconds_interval: float = 2.0,
description: str | None = None,
) -> Callable[[Callable], AbstractContextManager] | AbstractContextManager:
driver = self
class Poll:
def __init__(self, fun: Callable):
self.condition = PollingCondition(
fun,
driver.logger,
seconds_interval,
description,
)
def __enter__(self) -> None:
driver.polling_conditions.append(self.condition)
def __exit__(self, a, b, c) -> None: # type: ignore
res = driver.polling_conditions.pop()
assert res is self.condition
def wait(self, timeout: int = 900) -> None:
def condition(last: bool) -> bool:
if last:
driver.logger.info(
f"Last chance for {self.condition.description}"
)
ret = self.condition.check(force=True)
if not ret and not last:
driver.logger.info(
f"({self.condition.description} failure not fatal yet)"
)
return ret
with driver.logger.nested(f"waiting for {self.condition.description}"):
retry(condition, timeout=timeout)
if fun_ is None:
return Poll
else:
return Poll(fun_)