debian-forge/osbuild/api.py
Tom Gundersen 794ec97bf3 api: add barriers
Ensure that the api sockets are created before entering the with clause.

Signed-off-by: Tom Gundersen <teg@jklm.no>
2020-02-06 19:01:12 +01:00

78 lines
2.4 KiB
Python

import array
import asyncio
import json
import os
import socket
import sys
import tempfile
import threading
from . import remoteloop
class API:
def __init__(self, socket_address, args, interactive):
self.socket_address = socket_address
self.input = args
self.interactive = interactive
self._output = None
self.event_loop = asyncio.new_event_loop()
self.thread = threading.Thread(target=self._run_event_loop)
self.barrier = threading.Barrier(2)
@property
def output(self):
return self._output and self._output.read()
def _prepare_input(self):
with tempfile.TemporaryFile() as fd:
fd.write(json.dumps(self.input).encode('utf-8'))
# re-open the file to get a read-only file descriptor
return open(f"/proc/self/fd/{fd.fileno()}", "r")
def _prepare_output(self):
if self.interactive:
return os.fdopen(os.dup(sys.stdout.fileno()), 'w')
out = tempfile.TemporaryFile(mode="wb")
fd = os.open(f"/proc/self/fd/{out.fileno()}", os.O_RDONLY|os.O_CLOEXEC)
self._output = os.fdopen(fd)
return out
def _setup_stdio(self, sock, addr):
with self._prepare_input() as stdin, \
self._prepare_output() as stdout:
msg = {}
fds = array.array("i")
fds.append(stdin.fileno())
msg['stdin'] = 0
fds.append(stdout.fileno())
msg['stdout'] = 1
fds.append(stdout.fileno())
msg['stderr'] = 2
remoteloop.dump_fds(sock, msg, fds, addr=addr)
def _dispatch(self, sock):
msg, addr = sock.recvfrom(1024)
args = json.loads(msg)
if args["method"] == 'setup-stdio':
self._setup_stdio(sock, addr)
def _run_event_loop(self):
sock = socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM)
sock.bind(self.socket_address)
self.barrier.wait()
self.event_loop.add_reader(sock, self._dispatch, sock)
asyncio.set_event_loop(self.event_loop)
self.event_loop.run_forever()
self.event_loop.remove_reader(sock)
sock.close()
def __enter__(self):
self.thread.start()
self.barrier.wait()
return self
def __exit__(self, *args):
self.event_loop.call_soon_threadsafe(self.event_loop.stop)
self.thread.join()