========
Overview
Features
-
Uses unix domain sockets, only root or same effective user can connect.
-
Can run the connection in a thread or in a signal handler (see oneshot_on
option).
-
Can start the thread listening for connections from a signal handler (see activate_on
option)
-
Compatible with apps that fork, reinstalls the Manhole thread after fork - had to monkeypatch os.fork/os.forkpty for
this.
-
Compatible with gevent and eventlet with some limitations - you need to either:
- Use
oneshot_on
, or - Disable thread monkeypatching (eg:
gevent.monkey.patch_all(thread=False)
, eventlet.monkey_patch(thread=False)
Note: on eventlet you might <https://github.com/eventlet/eventlet/issues/401>
_ need to setup the hub first to prevent
circular import problems:
.. sourcecode:: python
import eventlet
eventlet.hubs.get_hub() # do this first
eventlet.monkey_patch(thread=False)
-
The thread is compatible with apps that use signalfd (will mask all signals for the Manhole threads).
Options
.. code-block:: python
manhole.install(
verbose=True,
verbose_destination=2,
patch_fork=True,
activate_on=None,
oneshot_on=None,
sigmask=manhole.ALL_SIGNALS,
socket_path=None,
reinstall_delay=0.5,
locals=None,
strict=True,
)
verbose
- Set it to False
to squelch the logging.verbose_destination
- Destination for verbose messages. Set it to a file descriptor or handle. Default is
unbuffered stderr (stderr 2
file descriptor).patch_fork
- Set it to False
if you don't want your os.fork
and os.forkpy
monkeypatchedactivate_on
- Set to "USR1"
, "USR2"
or some other signal name, or a number if you want the Manhole thread
to start when this signal is sent. This is desirable in case you don't want the thread active all the time.thread
- Set to True
to start the always-on ManholeThread. Default: True
.
Automatically switched to False
if oneshot_on
or activate_on
are used.oneshot_on
- Set to "USR1"
, "USR2"
or some other signal name, or a number if you want the Manhole to
listen for connection in the signal handler. This is desireable in case you don't want threads at all.sigmask
- Will set the signal mask to the given list (using signalfd.sigprocmask
). No action is done if
signalfd
is not importable. NOTE: This is done so that the Manhole thread doesn't steal any signals;
Normally that is fine because Python will force all the signal handling to be run in the main thread but signalfd
doesn't.socket_path
- Use a specific path for the unix domain socket (instead of /tmp/manhole-<pid>
). This disables
patch_fork
as children cannot reuse the same path.reinstall_delay
- Delay the unix domain socket creation reinstall_delay seconds. This alleviates
cleanup failures when using fork+exec patterns.locals
- Names to add to manhole interactive shell locals.daemon_connection
- The connection thread is daemonic (dies on app exit). Default: False
.redirect_stderr
- Redirect output from stderr to manhole console. Default: True
.strict
- If True
then AlreadyInstalled
will be raised when attempting to install manhole twice.
Default: True
.
Environment variable installation
Manhole can be installed via the PYTHONMANHOLE
environment variable.
This::
PYTHONMANHOLE='' python yourapp.py
Is equivalent to having this in yourapp.py
::
import manhole
manhole.install()
Any extra text in the environment variable is passed to manhole.install()
. Example::
PYTHONMANHOLE='oneshot_on="USR2"' python yourapp.py
What happens when you actually connect to the socket
- Credentials are checked (if it's same user or root)
sys.__std*__
/sys.std*
are redirected to the UDS- Stacktraces for each thread are written to the UDS
- REPL is started so you can fiddle with the process
Known issues
- Using threads and file handle (not raw file descriptor)
verbose_destination
can cause deadlocks. See bug reports:
PyPy <https://github.com/pypy/pypy/issues/1895>
_ and Python 3.4 <http://bugs.python.org/issue22697>
_.
SIGTERM and socket cleanup
By default Python doesn't call the atexit
callbacks with the default SIGTERM handling. This makes manhole leave
stray socket files around. If this is undesirable you should install a custom SIGTERM handler so atexit
is
properly invoked.
Example:
.. code-block:: python
import signal
import sys
def handle_sigterm(signo, frame):
sys.exit(128 + signo) # this will raise SystemExit and cause atexit to be called
signal.signal(signal.SIGTERM, handle_sigterm)
Using Manhole with uWSGI
Because uWSGI overrides signal handling Manhole is a bit more tricky to setup. One way is to use "uWSGI signals" (not
the POSIX signals) and have the workers check a file for the pid you want to open the Manhole in.
Stick something this in your WSGI application file:
.. sourcecode:: python
from __future__ import print_function
import sys
import os
import manhole
stack_dump_file = '/tmp/manhole-pid'
uwsgi_signal_number = 17
try:
import uwsgi
if not os.path.exists(stack_dump_file):
open(stack_dump_file, 'w')
def open_manhole(dummy_signum):
with open(stack_dump_file, 'r') as fh:
pid = fh.read().strip()
if pid == str(os.getpid()):
inst = manhole.install(strict=False, thread=False)
inst.handle_oneshot(dummy_signum, dummy_signum)
uwsgi.register_signal(uwsgi_signal_number, 'workers', open_manhole)
uwsgi.add_file_monitor(uwsgi_signal_number, stack_dump_file)
print("Listening for stack mahole requests via %r" % (stack_dump_file,), file=sys.stderr)
except ImportError:
print("Not running under uwsgi; unable to configure manhole trigger", file=sys.stderr)
except IOError:
print("IOError creating manhole trigger %r" % (stack_dump_file,), file=sys.stderr)
# somewhere bellow you'd have something like
from django.core.wsgi import get_wsgi_application
application = get_wsgi_application()
# or
def application(environ, start_response):
start_response('200 OK', [('Content-Type', 'text/plain'), ('Content-Length', '2')])
yield b'OK'
To open the Manhole just run echo 1234 > /tmp/manhole-pid
and then manhole-cli 1234
.
Requirements
:OS: Linux, OS X
:Runtime: Python 2.7, 3.4, 3.5, 3.6 or PyPy
Similar projects
- Twisted's
manhole <http://twistedmatrix.com/documents/current/api/twisted.conch.manhole.html>
__ - it has colors and
server-side history. wsgi-shell <https://github.com/GrahamDumpleton/wsgi-shell>
_ - spawns a thread.pyrasite <https://github.com/lmacken/pyrasite>
_ - uses gdb to inject code.pydbattach <https://github.com/albertz/pydbattach>
_ - uses gdb to inject code.pystuck <https://github.com/alonho/pystuck>
_ - very similar, uses rpyc <https://github.com/tomerfiliba/rpyc>
_ for
communication.pyringe <https://github.com/google/pyringe>
_ - uses gdb to inject code, more reliable, but relies on dbg
python
builds unfortunatelly.pdb-clone <https://pypi.python.org/pypi/pdb-clone>
_ - uses gdb to inject code, with a different strategy <https://code.google.com/p/pdb-clone/wiki/RemoteDebugging>
_.
Changelog
1.8.1 (2024-07-24)
- Fixed buffering issue on Python 3.11. See
66
. - Cleaned up some packaging/test problems.
- Removed more leftover Python 2 code.
- Fixed license metadata. See:
68
.
1.8.0 (2021-04-08)
- Simplified connection closing code.
Contributed by Anton Ryzhov in
62
. - Made connection shutdown in
manhole-cli
more graceful.
Contributed by Anton Ryzhov in 63
.
1.7.0 (2021-03-22)
- Fixed memory leak via
sys.last_type
, sys.last_value
, sys.last_traceback
.
Contributed by Anton Ryzhov in 59
. - Fixed a bunch of double-close bugs and simplified stream handler code.
Contributed by Anton Ryzhov in
58
. - Loosen up
pid
argument parsing in manhole-cli
to allow using paths with any prefix
(not just /tmp
).
1.6.0 (2019-01-19)
- Testing improvements (changed some skips to xfail, added osx in Travis).
- Fixed long standing Python 2.7 bug where
sys.getfilesystemencoding()
would be broken after installing a threaded
manhole. See 51
. - Dropped support for Python 2.6, 3.3 and 3.4.
- Fixed handling when
socket.setdefaulttimeout()
is used.
Contributed by "honnix" in 53
. - Fixed some typos. Contributed by Jesús Cea in
43
. - Fixed handling in
manhole-cli
so that timeout is actually seconds and not milliseconds.
Contributed by Nir Soffer in 45
. - Cleaned up useless polling options in
manhole-cli
.
Contributed by Nir Soffer in 46
. - Documented and implemented a solution for using Manhole with Eventlet.
See
49
.
1.5.0 (2017-08-31)
- Added two string aliases for
connection_handler
option. Now you can conveniently use connection_handler="exec"
. - Improved
handle_connection_exec
. It now has a clean way to exit (exit()
) and properly closes the socket.
1.4.0 (2017-08-29)
- Added the
connection_handler
install option. Default value is manhole.handle_connection_repl
, and alternate
manhole.handle_connection_exec
is provided (very simple: no output redirection, no stacktrace dumping). - Dropped Python 3.2 from the test grid. It may work but it's a huge pain to support (pip/pytest don't support it anymore).
- Added Python 3.5 and 3.6 in the test grid.
- Fixed issues with piping to
manhole-cli
. Now echo foobar | manhole-cli
will wait 1 second for output from manhole
(you can customize this with the --timeout
option). - Fixed issues with newer PyPy (caused by gevent/eventlet socket unwrapping).
1.3.0 (2015-09-03)
- Allowed Manhole to be configured without any thread or activation (in case you want to manually activate).
- Added an example and tests for using Manhole with uWSGi.
- Fixed error handling in
manhole-cli
on Python 3 (exc vars don't leak anymore). - Fixed support for running in gevent/eventlet-using apps on Python 3 (now that they support Python 3).
- Allowed reinstalling the manhole (in non-
strict
mode). Previous install is undone.
1.2.0 (2015-07-06)
-
Changed manhole-cli
:
- Won't spam the terminal with errors if socket file doesn't exist.
- Allowed sending any signal (new
--signal
argument). - Fixed some validation issues for the
PID
argument.
1.1.0 (2015-06-06)
- Added support for installing the manhole via the
PYTHONMANHOLE
environment variable. - Added a
strict
install option. Set it to false to avoid getting the AlreadyInstalled
exception. - Added a
manhole-cli
script that emulates socat readline unix-connect:/tmp/manhole-1234
.
1.0.0 (2014-10-13)
- Added
socket_path
install option (contributed by Nir Soffer
_). - Added
reinstall_delay
install option. - Added
locals
install option (contributed by Nir Soffer
_). - Added
redirect_stderr
install option (contributed by Nir Soffer
_). - Lots of internals cleanup (contributed by
Nir Soffer
_).
0.6.2 (2014-04-28)
0.6.1 (2014-04-28)
- Support for OS X (contributed by
Saulius Menkevičius
_).
.. _Saulius Menkevičius: https://github.com/razzmatazz
.. _Nir Soffer: https://github.com/nirs