tractor/examples/multihost/server.py

import httpx
import tractor
import trio

log = tractor.log.get_console_log(
    _root_name='my_app',
    name='server_thingy',
)


@tractor.context
async def proxy_request(
    ctx: tractor.Context,
    address: str,
):
    log.info(
        'Rxed client request\n'
        f'{address}\n'
    )
    async with httpx.AsyncClient() as client:
        await ctx.started()  # signal the remote task has started its client
        log.info(
            'Opened `httpx` client..'
        )

        resp: httpx.Response = await client.get(address)  # do the proxied request, get response.
        log.info(
            'Got response..\n'
            f'{resp}\n'
        )

        # only breaking this up to clarify that you didn't have to only return a single result you could have opened
        # a long lived stream to avoid task spawning overhead in this service actor.. but more on that later..
        #
        # NOTEs, cast to `str` here since we can't serialize the
        # response type for the wire directly, at least no without
        # a custom `msgspec.Decoder`!!
        return str(resp)

        # return resp
        # ^TODO, various typed msging options:
        # -[ ] try returning just the `resp` verbatim => should raise
        #    an MTE
        # -[ ] try defining a custom `Response` msg to proxy the orig
        #     types fields and/or a decoder to serialize it?


async def main():

    # enable console logging for our custom app's logger
    tractor.log.get_console_log(
        level='info',
        _root_name='my_app',
        name='server_thingy',
    )

    # since (originally) this is run as a script, we will end up with
    # `__name__ == '__main__'` so to ensure the rpc request from the
    # client isn't blocked by `tractor.ModuleNotFound`, we want to just
    # use the explicit file-as-module name.. why u ask?
    this_mod: str = 'server'
    # WELP, when the `Portal.open_context()` api (used in
    # `client.py`) requests the RPC-ctx ep it will send
    # a `str`-like-ptr encoding the func-ref in form expected by
    # `pkgutil.resolve_name()`.
    #
    # Since the client's local namespace reference/path to this
    # `.server.py` mod will be from a direct manual import, that
    # `proxy_request()`-ref will render as `'server:proxy_request'`
    # (as delivered from `NamespacePath.from_ref()` since that's how
    # `.open_context()` serializes the func's-ref for IPC transit).
    # SO, we need to be sure we "enable" this module name so that the
    # nsp maps to an enabled module in the `Actor._mods: dict`.

    async with tractor.open_root_actor(
        name='web_proxier',
        registry_addrs=[('127.0.0.1', 1616)],
        enable_modules=[this_mod],
        loglevel='info',
    ):
        # just block waiting for a peer actor to connect and open an
        # RPC context using the above proxy endpoint.
        log.info(
            'proxy server up bby!\n'
            'waiting to serve some requests..\n'
        )
        await trio.sleep_forever()


if __name__ == '__main__':
    trio.run(main)