Heroku/hikka/web/proxypass.py

101 lines
3.1 KiB
Python

import asyncio
import logging
import re
import typing
from .. import utils
logger = logging.getLogger(__name__)
class ProxyPasser:
def __init__(self):
self._tunnel_url = None
self._sproc = None
self._url_available = asyncio.Event()
self._url_available.set()
self._lock = asyncio.Lock()
async def _sleep_for_task(self, callback: callable, data: bytes, delay: int):
await asyncio.sleep(delay)
await callback(data.decode("utf-8"))
async def _read_stream(
self,
callback: callable,
stream: typing.BinaryIO,
delay: int,
) -> None:
last_task = None
for getline in iter(stream.readline, ""):
data_chunk = await getline
if not data_chunk:
if last_task:
last_task.cancel()
await callback(data_chunk.decode("utf-8"))
if not self._url_available.is_set():
self._url_available.set()
if last_task:
last_task.cancel()
last_task = asyncio.ensure_future(
self._sleep_for_task(callback, data_chunk, delay)
)
def kill(self):
try:
self._sproc.terminate()
except Exception:
logger.exception("Failed to kill proxy pass process")
else:
logger.debug("Proxy pass tunnel killed")
async def _process_stream(self, stdout_line: str) -> None:
regex = r"tunneled.*?(https:\/\/.*?\..*?\.[a-z]+)"
if re.search(regex, stdout_line):
logger.debug("Proxy pass tunneled: %s", stdout_line)
self._tunnel_url = re.search(regex, stdout_line)[1]
self._url_available.set()
async def get_url(self, port: int) -> typing.Optional[str]:
async with self._lock:
if self._tunnel_url:
try:
await asyncio.wait_for(self._sproc.wait(), timeout=0.1)
except asyncio.TimeoutError:
return self._tunnel_url
else:
self.kill()
logger.debug("Starting proxy pass shell")
self._sproc = await asyncio.create_subprocess_shell(
"ssh -o StrictHostKeyChecking=no -R"
f" 80:127.0.0.1:{port} nokey@localhost.run",
stdin=asyncio.subprocess.PIPE,
stdout=asyncio.subprocess.PIPE,
stderr=asyncio.subprocess.PIPE,
)
utils.atexit(self.kill)
self._url_available = asyncio.Event()
logger.debug("Starting proxy pass reader")
asyncio.ensure_future(
self._read_stream(
self._process_stream,
self._sproc.stdout,
1,
)
)
try:
await asyncio.wait_for(self._url_available.wait(), 15)
except asyncio.TimeoutError:
self.kill()
self._tunnel_url = None
return await self.get_url(port)
return self._tunnel_url