source/projects/activitypub_relay/src/python/relay/application.py

import asyncio
from datetime import datetime, timedelta
import logging
import os
import signal
from uuid import uuid4

from aiohttp import web
from cachetools import LRUCache
from relay.config import RelayConfig
from relay.database import RelayDatabase
from relay.misc import (
    check_open_port,
    DotDict,
    set_app,
)
from relay.views import routes


class Application(web.Application):
    def __init__(self, cfgpath, middlewares=None):
        web.Application.__init__(self, middlewares=middlewares)

        self["starttime"] = None
        self["running"] = False
        self["is_docker"] = bool(os.environ.get("DOCKER_RUNNING"))
        self["config"] = RelayConfig(cfgpath)

        if not self["config"].load():
            self["config"].save()

        self["database"] = RelayDatabase(self["config"])
        self["database"].load()

        self["cache"] = DotDict(
            {
                key: Cache(maxsize=self["config"][key])
                for key in self["config"].cachekeys
            }
        )
        self["semaphore"] = asyncio.Semaphore(self["config"].push_limit)

        self.set_signal_handler()
        set_app(self)

    @property
    def cache(self):
        return self["cache"]

    @property
    def config(self):
        return self["config"]

    @property
    def database(self):
        return self["database"]

    @property
    def is_docker(self):
        return self["is_docker"]

    @property
    def semaphore(self):
        return self["semaphore"]

    @property
    def uptime(self):
        if not self["starttime"]:
            return timedelta(seconds=0)

        uptime = datetime.now() - self["starttime"]

        return timedelta(seconds=uptime.seconds)

    def set_signal_handler(self):
        signal.signal(signal.SIGHUP, self.stop)
        signal.signal(signal.SIGINT, self.stop)
        signal.signal(signal.SIGQUIT, self.stop)
        signal.signal(signal.SIGTERM, self.stop)

    def run(self):
        if not check_open_port(self.config.listen, self.config.port):
            return logging.error(
                f"A server is already running on port {self.config.port}"
            )

        for route in routes:
            self.router.add_route(*route)

        logging.info(
            f"Starting webserver at {self.config.host} ({self.config.listen}:{self.config.port})"
        )
        asyncio.run(self.handle_run())

        # Save off config before exit
        self.config.save()
        self.database.save()

    def stop(self, *_):
        self["running"] = False

    async def handle_run(self):
        self["running"] = True

        runner = web.AppRunner(
            self, access_log_format='%{X-Forwarded-For}i "%r" %s %b "%{User-Agent}i"'
        )
        await runner.setup()

        site = web.TCPSite(
            runner, host=self.config.listen, port=self.config.port, reuse_address=True
        )

        await site.start()
        self["starttime"] = datetime.now()

        while self["running"]:
            await asyncio.sleep(0.25)

        await site.stop()

        self["starttime"] = None
        self["running"] = False


class Cache(LRUCache):
    def set_maxsize(self, value):
        self.__maxsize = int(value)


@web.middleware
async def request_id_middleware(request, handler):
    request.id = uuid4()
    return await handler(request)