mirror of
https://github.com/n8n-io/n8n
synced 2026-05-10 13:32:23 +02:00
410 lines
12 KiB
Python
410 lines
12 KiB
Python
from queue import Empty
|
|
import multiprocessing
|
|
import traceback
|
|
import textwrap
|
|
import json
|
|
import io
|
|
import os
|
|
import sys
|
|
import logging
|
|
|
|
from src.errors import (
|
|
TaskCancelledError,
|
|
TaskResultMissingError,
|
|
TaskRuntimeError,
|
|
TaskTimeoutError,
|
|
TaskProcessExitError,
|
|
)
|
|
|
|
from src.message_types.broker import NodeMode, Items
|
|
from src.constants import (
|
|
EXECUTOR_CIRCULAR_REFERENCE_KEY,
|
|
EXECUTOR_USER_OUTPUT_KEY,
|
|
EXECUTOR_ALL_ITEMS_FILENAME,
|
|
EXECUTOR_PER_ITEM_FILENAME,
|
|
SIGTERM_EXIT_CODE,
|
|
)
|
|
from typing import Any, Set
|
|
|
|
from multiprocessing.context import ForkServerProcess
|
|
from multiprocessing import shared_memory
|
|
|
|
logger = logging.getLogger(__name__)
|
|
|
|
MULTIPROCESSING_CONTEXT = multiprocessing.get_context("forkserver")
|
|
MAX_PRINT_ARGS_ALLOWED = 100
|
|
|
|
PrintArgs = list[list[Any]] # Args to all `print()` calls in a Python code task
|
|
|
|
|
|
class TaskExecutor:
|
|
"""Responsible for executing Python code tasks in isolated subprocesses."""
|
|
|
|
@staticmethod
|
|
def create_process(
|
|
code: str,
|
|
node_mode: NodeMode,
|
|
items: Items,
|
|
stdlib_allow: Set[str],
|
|
external_allow: Set[str],
|
|
builtins_deny: set[str],
|
|
):
|
|
"""Create a subprocess for executing a Python code task and a queue for communication."""
|
|
|
|
fn = (
|
|
TaskExecutor._all_items
|
|
if node_mode == "all_items"
|
|
else TaskExecutor._per_item
|
|
)
|
|
|
|
queue = MULTIPROCESSING_CONTEXT.Queue()
|
|
process = MULTIPROCESSING_CONTEXT.Process(
|
|
target=fn,
|
|
args=(
|
|
code,
|
|
items,
|
|
queue,
|
|
stdlib_allow,
|
|
external_allow,
|
|
builtins_deny,
|
|
),
|
|
)
|
|
|
|
return process, queue
|
|
|
|
@staticmethod
|
|
def execute_process(
|
|
process: ForkServerProcess,
|
|
queue: multiprocessing.Queue,
|
|
task_timeout: int,
|
|
continue_on_fail: bool,
|
|
) -> tuple[list, PrintArgs, int]:
|
|
"""Execute a subprocess for a Python code task."""
|
|
|
|
print_args: PrintArgs = []
|
|
|
|
try:
|
|
try:
|
|
process.start()
|
|
except (ProcessLookupError, ConnectionError, BrokenPipeError) as e:
|
|
logger.error(f"Failed to start child process: {e}")
|
|
raise TaskProcessExitError(-1)
|
|
|
|
process.join(timeout=task_timeout)
|
|
|
|
if process.is_alive():
|
|
TaskExecutor.stop_process(process)
|
|
raise TaskTimeoutError(task_timeout)
|
|
|
|
if process.exitcode == SIGTERM_EXIT_CODE:
|
|
raise TaskCancelledError()
|
|
|
|
if process.exitcode != 0:
|
|
assert process.exitcode is not None
|
|
raise TaskProcessExitError(process.exitcode)
|
|
|
|
try:
|
|
returned = queue.get_nowait()
|
|
except Empty:
|
|
raise TaskResultMissingError()
|
|
except EOFError as e:
|
|
logger.error(f"Failed to retrieve results from child process: {e}")
|
|
raise TaskResultMissingError()
|
|
|
|
finally:
|
|
queue.close()
|
|
queue.join_thread()
|
|
|
|
if "error" in returned:
|
|
raise TaskRuntimeError(returned["error"])
|
|
|
|
if "shm_name" not in returned:
|
|
raise TaskResultMissingError()
|
|
|
|
shm_name = returned["shm_name"]
|
|
shm_size = returned["shm_size"]
|
|
try:
|
|
shm = shared_memory.SharedMemory(name=shm_name)
|
|
try:
|
|
json_str = bytes(shm.buf[:shm_size]).decode("utf-8")
|
|
result = json.loads(json_str)
|
|
finally:
|
|
shm.close()
|
|
shm.unlink()
|
|
except FileNotFoundError:
|
|
raise TaskResultMissingError()
|
|
|
|
print_args = returned.get("print_args", [])
|
|
|
|
return result, print_args, shm_size
|
|
|
|
except Exception as e:
|
|
if continue_on_fail:
|
|
return [{"json": {"error": str(e)}}], print_args, 0
|
|
raise
|
|
|
|
@staticmethod
|
|
def stop_process(process: ForkServerProcess | None):
|
|
"""Stop a running subprocess, gracefully else force-killing."""
|
|
|
|
if process is None or not process.is_alive():
|
|
return
|
|
|
|
try:
|
|
process.terminate()
|
|
process.join(timeout=1) # 1s grace period
|
|
|
|
if process.is_alive():
|
|
process.kill()
|
|
except (ProcessLookupError, ConnectionError, BrokenPipeError):
|
|
# subprocess is dead or unreachable
|
|
pass
|
|
|
|
@staticmethod
|
|
def _all_items(
|
|
raw_code: str,
|
|
items: Items,
|
|
queue: multiprocessing.Queue,
|
|
stdlib_allow: Set[str],
|
|
external_allow: Set[str],
|
|
builtins_deny: set[str],
|
|
):
|
|
"""Execute a Python code task in all-items mode."""
|
|
|
|
os.environ.clear()
|
|
|
|
TaskExecutor._sanitize_sys_modules(stdlib_allow, external_allow)
|
|
|
|
print_args: PrintArgs = []
|
|
sys.stderr = stderr_capture = io.StringIO()
|
|
|
|
try:
|
|
wrapped_code = TaskExecutor._wrap_code(raw_code)
|
|
compiled_code = compile(wrapped_code, EXECUTOR_ALL_ITEMS_FILENAME, "exec")
|
|
|
|
globals = {
|
|
"__builtins__": TaskExecutor._filter_builtins(builtins_deny),
|
|
"_items": items,
|
|
"print": TaskExecutor._create_custom_print(print_args),
|
|
}
|
|
|
|
exec(compiled_code, globals)
|
|
|
|
result = globals[EXECUTOR_USER_OUTPUT_KEY]
|
|
TaskExecutor._put_result(queue, result, print_args)
|
|
|
|
except BaseException as e:
|
|
TaskExecutor._put_error(queue, e, stderr_capture.getvalue(), print_args)
|
|
|
|
@staticmethod
|
|
def _per_item(
|
|
raw_code: str,
|
|
items: Items,
|
|
queue: multiprocessing.Queue,
|
|
stdlib_allow: Set[str],
|
|
external_allow: Set[str],
|
|
builtins_deny: set[str],
|
|
):
|
|
"""Execute a Python code task in per-item mode."""
|
|
|
|
os.environ.clear()
|
|
|
|
TaskExecutor._sanitize_sys_modules(stdlib_allow, external_allow)
|
|
|
|
print_args: PrintArgs = []
|
|
sys.stderr = stderr_capture = io.StringIO()
|
|
|
|
try:
|
|
wrapped_code = TaskExecutor._wrap_code(raw_code)
|
|
compiled_code = compile(wrapped_code, EXECUTOR_PER_ITEM_FILENAME, "exec")
|
|
|
|
result = []
|
|
for index, item in enumerate(items):
|
|
globals = {
|
|
"__builtins__": TaskExecutor._filter_builtins(builtins_deny),
|
|
"_item": item,
|
|
"print": TaskExecutor._create_custom_print(print_args),
|
|
}
|
|
|
|
exec(compiled_code, globals)
|
|
|
|
user_output = globals[EXECUTOR_USER_OUTPUT_KEY]
|
|
|
|
if user_output is None:
|
|
continue
|
|
|
|
user_output["pairedItem"] = {"item": index}
|
|
result.append(user_output)
|
|
|
|
TaskExecutor._put_result(queue, result, print_args)
|
|
|
|
except BaseException as e:
|
|
TaskExecutor._put_error(queue, e, stderr_capture.getvalue(), print_args)
|
|
|
|
@staticmethod
|
|
def _wrap_code(raw_code: str) -> str:
|
|
indented_code = textwrap.indent(raw_code, " ")
|
|
return f"def _user_function():\n{indented_code}\n\n{EXECUTOR_USER_OUTPUT_KEY} = _user_function()"
|
|
|
|
@staticmethod
|
|
def _put_result(
|
|
queue: multiprocessing.Queue, result: list[Any], print_args: PrintArgs
|
|
):
|
|
json_bytes = json.dumps(result, default=str, ensure_ascii=False).encode("utf-8")
|
|
json_bytes_size = len(json_bytes)
|
|
|
|
shm = shared_memory.SharedMemory(create=True, size=json_bytes_size)
|
|
shm.buf[:json_bytes_size] = json_bytes
|
|
|
|
print_args_to_send = TaskExecutor._truncate_print_args(print_args)
|
|
queue.put(
|
|
{
|
|
"shm_name": shm.name,
|
|
"shm_size": json_bytes_size, # stay exact, shm.size can round up for alignment
|
|
"print_args": print_args_to_send,
|
|
}
|
|
)
|
|
|
|
shm.close()
|
|
|
|
@staticmethod
|
|
def _put_error(
|
|
queue: multiprocessing.Queue,
|
|
e: BaseException,
|
|
stderr: str = "",
|
|
print_args: PrintArgs = [],
|
|
):
|
|
error_dict = {
|
|
"message": f"Process exited with code {e.code}"
|
|
if isinstance(e, SystemExit)
|
|
else str(e),
|
|
"stack": traceback.format_exc(),
|
|
"stderr": stderr,
|
|
}
|
|
|
|
print_args_to_send = TaskExecutor._truncate_print_args(print_args)
|
|
|
|
queue.put(
|
|
{
|
|
"error": error_dict,
|
|
"print_args": print_args_to_send,
|
|
}
|
|
)
|
|
|
|
# ========== print() ==========
|
|
|
|
@staticmethod
|
|
def _create_custom_print(print_args: PrintArgs):
|
|
def custom_print(*args):
|
|
serializable_args = []
|
|
|
|
for arg in args:
|
|
try:
|
|
json.dumps(arg, default=str, ensure_ascii=False)
|
|
serializable_args.append(arg)
|
|
except Exception as _:
|
|
# Ensure args are serializable so they are transmissible
|
|
# through the multiprocessing queue and via websockets.
|
|
serializable_args.append(
|
|
{
|
|
EXECUTOR_CIRCULAR_REFERENCE_KEY: repr(arg),
|
|
"__type__": type(arg).__name__,
|
|
}
|
|
)
|
|
|
|
formatted = TaskExecutor._format_print_args(*serializable_args)
|
|
print_args.append(formatted)
|
|
print("[user code]", *args)
|
|
|
|
return custom_print
|
|
|
|
@staticmethod
|
|
def _format_print_args(*args) -> list[str]:
|
|
"""
|
|
Takes the args passed to a `print()` call in user code and converts them
|
|
to string representations suitable for display in a browser console.
|
|
|
|
Expects all args to be serializable.
|
|
"""
|
|
|
|
formatted = []
|
|
|
|
for arg in args:
|
|
if isinstance(arg, str):
|
|
formatted.append(f"'{arg}'")
|
|
|
|
elif arg is None or isinstance(arg, (int, float, bool)):
|
|
formatted.append(str(arg))
|
|
|
|
elif isinstance(arg, dict) and EXECUTOR_CIRCULAR_REFERENCE_KEY in arg:
|
|
formatted.append(f"[Circular {arg.get('__type__', 'Object')}]")
|
|
|
|
else:
|
|
formatted.append(json.dumps(arg, default=str, ensure_ascii=False))
|
|
|
|
return formatted
|
|
|
|
@staticmethod
|
|
def _truncate_print_args(print_args: PrintArgs) -> PrintArgs:
|
|
"""Truncate print_args to prevent pipe buffer overflow."""
|
|
|
|
if not print_args or len(print_args) <= MAX_PRINT_ARGS_ALLOWED:
|
|
return print_args
|
|
|
|
truncated = print_args[:MAX_PRINT_ARGS_ALLOWED]
|
|
truncated.append(
|
|
[
|
|
f"[Output truncated - {len(print_args) - MAX_PRINT_ARGS_ALLOWED} more print statements]"
|
|
]
|
|
)
|
|
|
|
return truncated
|
|
|
|
# ========== security ==========
|
|
|
|
@staticmethod
|
|
def _filter_builtins(builtins_deny: set[str]):
|
|
"""Get __builtins__ with denied ones removed."""
|
|
|
|
if len(builtins_deny) == 0:
|
|
return __builtins__
|
|
|
|
return {k: v for k, v in __builtins__.items() if k not in builtins_deny}
|
|
|
|
@staticmethod
|
|
def _sanitize_sys_modules(stdlib_allow: Set[str], external_allow: Set[str]):
|
|
safe_modules = {
|
|
"builtins",
|
|
"__main__",
|
|
"sys",
|
|
"traceback",
|
|
"linecache",
|
|
"importlib",
|
|
"importlib.machinery",
|
|
}
|
|
|
|
if "*" in stdlib_allow:
|
|
safe_modules.update(sys.stdlib_module_names)
|
|
else:
|
|
safe_modules.update(stdlib_allow)
|
|
|
|
if "*" in external_allow:
|
|
safe_modules.update(
|
|
name
|
|
for name in sys.modules.keys()
|
|
if name not in sys.stdlib_module_names
|
|
)
|
|
else:
|
|
safe_modules.update(external_allow)
|
|
|
|
# keep modules marked as safe and submodules of those
|
|
modules_to_remove = [
|
|
name
|
|
for name in sys.modules.keys()
|
|
if name not in safe_modules
|
|
and not any(name.startswith(safe + ".") for safe in safe_modules)
|
|
]
|
|
|
|
for module_name in modules_to_remove:
|
|
del sys.modules[module_name]
|