# coding: utf-8
#
# Postfix queue control python tool (pymailq)
#
# Copyright (C) 2014 Denis Pompilio (jawa) <denis.pompilio@gmail.com>
#
# This file is part of pymailq
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, see <http://www.gnu.org/licenses/>.
import time
import subprocess
from pymailq import CONFIG, debug
[docs]class QueueControl(object):
"""
Postfix queue control using postsuper command.
The :class:`~control.QueueControl` instance defines the following
attributes:
.. attribute:: use_sudo
Boolean to control the use of `sudo` to invoke Postfix command.
Default is ``False``
.. attribute:: postsuper_cmd
Postfix command and arguments :func:`list` for mails queue
administrative operations. Default is ``["postsuper"]``
.. attribute:: known_operations
Known Postfix administrative operations :class:`dict` to associate
operations to command arguments. Known associations are::
delete: -d
hold: -h
release: -H
requeue: -r
.. warning::
Default known associations are provided for the default mails
queue administrative command `postsuper`_.
.. seealso::
Postfix manual:
`postsuper`_ -- Postfix superintendent
"""
[docs] @staticmethod
def get_operation_cmd(operation):
"""Get operation related command from configuration
This method use Postfix administrative commands defined
in :attr:`pymailq.CONFIG` attribute under the key 'list_queue'.
Command and arguments list is build on call with the configuration data.
Command keys are built with the ``operation`` argument suffixed with
``_message``. Example: ``hold_message`` for the hold command.
:param str operation: Operation name
:return: Command and arguments as :class:`list`
:raise KeyError: Operation is unknown
.. seealso::
:ref:`pymailq-configuration`
"""
cmd = CONFIG['commands'][operation + '_message']
if CONFIG['commands']['use_sudo']:
cmd.insert(0, 'sudo')
return cmd
[docs] @debug
def _operate(self, operation, messages):
"""
Generic method to lead operations messages from postfix mail queue.
Operations can be one of Postfix known operations stored in
PyMailq module configuration.
:param str operation: Known operation from :attr:`pymailq.CONFIG`.
:param list messages: List of :class:`~store.Mail` objects targetted
for operation.
:return: Command's *stderr* output lines
:rtype: :func:`list`
"""
# validate that object's attribute "qid" exist. Raise AttributeError.
for msg in messages:
getattr(msg, "qid")
# We may modify this part to improve security.
# It should not be possible to inject commands, but who knows...
# https://www.kevinlondon.com/2015/07/26/dangerous-python-functions.html
# And consider the use of sh module: https://amoffat.github.io/sh/
operation_cmd = self.get_operation_cmd(operation) + ['-']
try:
child = subprocess.Popen(operation_cmd,
stdin=subprocess.PIPE,
stderr=subprocess.PIPE)
except EnvironmentError as exc:
command_str = " ".join(operation_cmd)
error_msg = "Unable to call '%s': %s" % (command_str, str(exc))
raise RuntimeError(error_msg)
# If permissions error, the postsuper process takes ~1s to teardown.
# Wait this delay and raise error message if process has stopped.
time.sleep(1.1)
child.poll()
if child.returncode:
raise RuntimeError(child.communicate()[1].strip().decode())
try:
for msg in messages:
child.stdin.write((msg.qid+'\n').encode())
stderr = child.communicate()[1].strip()
except BrokenPipeError:
raise RuntimeError("Unexpected error: child process has crashed")
return [line.strip() for line in stderr.decode().split('\n')]
[docs] def delete_messages(self, messages):
"""
Delete several messages from postfix mail queue.
This method is a :func:`~functools.partial` wrapper on
:meth:`~control.QueueControl._operate`. Passed operation is ``delete``
"""
return self._operate('delete', messages)
[docs] def hold_messages(self, messages):
"""
Hold several messages from postfix mail queue.
This method is a :func:`~functools.partial` wrapper on
:meth:`~control.QueueControl._operate`. Passed operation is ``hold``
"""
return self._operate('hold', messages)
[docs] def release_messages(self, messages):
"""
Release several messages from postfix mail queue.
This method is a :func:`~functools.partial` wrapper on
:meth:`~control.QueueControl._operate`. Passed operation is ``release``
"""
return self._operate('release', messages)
[docs] def requeue_messages(self, messages):
"""
Requeue several messages from postfix mail queue.
This method is a :func:`~functools.partial` wrapper on
:meth:`~control.QueueControl._operate`. Passed operation is ``requeue``
"""
return self._operate('requeue', messages)