Files
pycapnp/examples/async_ssl_server.py
2023-03-12 11:33:41 -07:00

147 lines
3.9 KiB
Python
Executable File

#!/usr/bin/env python3
import argparse
import asyncio
import logging
import os
import socket
import ssl
import capnp
import thread_capnp
logger = logging.getLogger(__name__)
logger.setLevel(logging.DEBUG)
this_dir = os.path.dirname(os.path.abspath(__file__))
class ExampleImpl(thread_capnp.Example.Server):
"Implementation of the Example threading Cap'n Proto interface."
def subscribeStatus(self, subscriber, **kwargs):
return (
capnp.getTimer()
.after_delay(10**9)
.then(lambda: subscriber.status(True))
.then(lambda _: self.subscribeStatus(subscriber))
)
def longRunning(self, **kwargs):
return capnp.getTimer().after_delay(1 * 10**9)
def alive(self, **kwargs):
return True
class Server:
async def myreader(self):
while self.retry:
try:
# Must be a wait_for so we don't block on read()
data = await asyncio.wait_for(self.reader.read(4096), timeout=0.1)
except asyncio.TimeoutError:
logger.debug("myreader timeout.")
continue
except Exception as err:
logger.error("Unknown myreader err: %s", err)
return False
await self.server.write(data)
logger.debug("myreader done.")
return True
async def mywriter(self):
while self.retry:
try:
# Must be a wait_for so we don't block on read()
data = await asyncio.wait_for(self.server.read(4096), timeout=0.1)
self.writer.write(data.tobytes())
except asyncio.TimeoutError:
logger.debug("mywriter timeout.")
continue
except Exception as err:
logger.error("Unknown mywriter err: %s", err)
return False
logger.debug("mywriter done.")
return True
async def myserver(self, reader, writer):
# Start TwoPartyServer using TwoWayPipe (only requires bootstrap)
self.server = capnp.TwoPartyServer(bootstrap=ExampleImpl())
self.reader = reader
self.writer = writer
self.retry = True
# Assemble reader and writer tasks, run in the background
coroutines = [self.myreader(), self.mywriter()]
tasks = asyncio.gather(*coroutines, return_exceptions=True)
while True:
self.server.poll_once()
# Check to see if reader has been sent an eof (disconnect)
if self.reader.at_eof():
self.retry = False
break
await asyncio.sleep(0.01)
# Make wait for reader/writer to finish (prevent possible resource leaks)
await tasks
async def new_connection(reader, writer):
server = Server()
await server.myserver(reader, writer)
def parse_args():
parser = argparse.ArgumentParser(
usage="""Runs the server bound to the\
given address/port ADDRESS. """
)
parser.add_argument("address", help="ADDRESS:PORT")
return parser.parse_args()
async def main():
address = parse_args().address
host = address.split(":")
addr = host[0]
port = host[1]
# Setup SSL context
ctx = ssl.create_default_context(ssl.Purpose.CLIENT_AUTH)
ctx.load_cert_chain(
os.path.join(this_dir, "selfsigned.cert"),
os.path.join(this_dir, "selfsigned.key"),
)
# Handle both IPv4 and IPv6 cases
try:
print("Try IPv4")
server = await asyncio.start_server(
new_connection,
addr,
port,
ssl=ctx,
family=socket.AF_INET,
)
except Exception:
print("Try IPv6")
server = await asyncio.start_server(
new_connection,
addr,
port,
ssl=ctx,
family=socket.AF_INET6,
)
async with server:
await server.serve_forever()
if __name__ == "__main__":
asyncio.run(main())