source: mod_gnutls/test/mgstest/http.py @ 6d3dc34

#!/usr/bin/python3

# Copyright 2019 Fiona Klute
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import socket
import subprocess

from http.client import HTTPConnection
from multiprocessing import Process

class HTTPSubprocessConnection(HTTPConnection):
    def __init__(self, command, host, port=None,
                 output_filter=None,
                 timeout=socket._GLOBAL_DEFAULT_TIMEOUT,
                 blocksize=8192):
        super(HTTPSubprocessConnection, self).__init__(host, port, timeout,
                                                       source_address=None,
                                                       blocksize=blocksize)
        # "command" must be a list containing binary and command line
        # parameters
        self.command = command
        # This will be the subprocess reference when connected
        self._sproc = None
        # The subprocess return code is stored here on close()
        self.returncode = None
        # The set_tunnel method of the super class is not supported
        # (see exception doc)
        self.set_tunnel = None
        # This method will be run in a separate process and filter the
        # stdout of self._sproc. Its arguments are self._sproc.stdout
        # and the socket back to the HTTP connection (write-only).
        self._output_filter = output_filter
        # output filter process
        self._fproc = None

    def connect(self):
        s_local, s_remote = socket.socketpair(socket.AF_UNIX,
                                              socket.SOCK_STREAM)
        s_local.settimeout(self.timeout)

        # TODO: Maybe capture stderr?
        if self._output_filter:
            self._sproc = subprocess.Popen(self.command, stdout=subprocess.PIPE,
                                           stdin=s_remote, close_fds=True,
                                           bufsize=0)
            self._fproc = Process(target=self._output_filter,
                                  args=(self._sproc.stdout, s_remote))
            self._fproc.start()
        else:
            self._sproc = subprocess.Popen(self.command, stdout=s_remote,
                                           stdin=s_remote, close_fds=True,
                                           bufsize=0)
        s_remote.close()
        self.sock = s_local

    def close(self):
        # close socket to subprocess for writing
        if self.sock:
            self.sock.shutdown(socket.SHUT_WR)

        # Wait for the process to stop, send SIGTERM/SIGKILL if
        # necessary
        if self._sproc:
            try:
                self.returncode = self._sproc.wait(self.timeout)
            except subprocess.TimeoutExpired:
                try:
                    self._sproc.terminate()
                    self.returncode = self._sproc.wait(self.timeout)
                except subprocess.TimeoutExpired:
                    self._sproc.kill()
                    self.returncode = self._sproc.wait(self.timeout)

        # filter process receives HUP on pipe when the subprocess
        # terminates
        if self._fproc:
            self._fproc.join()

        # close the connection in the super class, which also calls
        # self.sock.close()
        super().close()