From 4cae5531ec058455967c38cfa7d5e63a4a61d6ed Mon Sep 17 00:00:00 2001 From: Sebastien Bourdeauducq Date: Tue, 28 Oct 2014 15:45:56 +0800 Subject: [PATCH] pc_rpc: server identification support --- artiq/devices/pdq2/pdq2-client | 2 +- artiq/devices/pdq2/pdq2-controller | 3 +- artiq/management/pc_rpc.py | 64 ++++++++++++++++++++++++------ doc/manual/writing_a_driver.rst | 9 ++++- frontend/artiq | 2 +- frontend/artiqd | 2 +- frontend/identify-controller | 30 ++++++++++++++ test/pc_rpc.py | 5 ++- 8 files changed, 97 insertions(+), 20 deletions(-) create mode 100755 frontend/identify-controller diff --git a/artiq/devices/pdq2/pdq2-client b/artiq/devices/pdq2/pdq2-client index a04809489..1386a347f 100755 --- a/artiq/devices/pdq2/pdq2-client +++ b/artiq/devices/pdq2/pdq2-client @@ -54,7 +54,7 @@ def _get_args(): def _main(): args = _get_args() - dev = Client(args.server, args.port) + dev = Client(args.server, args.port, "pdq2") dev.init() if args.reset: diff --git a/artiq/devices/pdq2/pdq2-controller b/artiq/devices/pdq2/pdq2-controller index e623155f0..579c72bc9 100755 --- a/artiq/devices/pdq2/pdq2-controller +++ b/artiq/devices/pdq2/pdq2-controller @@ -355,7 +355,8 @@ def main(): dev = Pdq2(serial=args.serial) try: - simple_server_loop(dev, args.bind, args.port) + simple_server_loop(dev, "pdq2", args.bind, args.port, + id_parameters="serial="+str(args.serial)) finally: dev.close() diff --git a/artiq/management/pc_rpc.py b/artiq/management/pc_rpc.py index 445378917..e8bf65c77 100644 --- a/artiq/management/pc_rpc.py +++ b/artiq/management/pc_rpc.py @@ -14,8 +14,16 @@ from artiq.management import pyon class RemoteError(Exception): - """Exception raised when a RPC failed or raised an exception on the - remote (server) side. + """Raised when a RPC failed or raised an exception on the remote (server) + side. + + """ + pass + + +class IncompatibleServer(Exception): + """Raised by the client when attempting to connect to a server that does + not have the expected type. """ pass @@ -44,10 +52,21 @@ class Client: hostname or a IPv4 or IPv6 address (see ``socket.create_connection`` in the Python standard library). :param port: TCP port to use. + :param expected_id_type: Server type to expect. ``IncompatibleServer`` is + raised when the types do not match. Use ``None`` to accept any server + type. """ - def __init__(self, host, port): + def __init__(self, host, port, expected_id_type): self.socket = socket.create_connection((host, port)) + self._identify(expected_id_type) + + def get_rpc_id(self): + """Returns a dictionary containing the identification information of + the server. + + """ + return self._server_identification def close_rpc(self): """Closes the connection to the RPC server. @@ -57,8 +76,7 @@ class Client: """ self.socket.close() - def _do_rpc(self, name, args, kwargs): - obj = {"action": "call", "name": name, "args": args, "kwargs": kwargs} + def _send_recv(self, obj): line = pyon.encode(obj) + "\n" self.socket.sendall(line.encode()) @@ -69,6 +87,19 @@ class Client: break buf += more.decode() obj = pyon.decode(buf) + + return obj + + def _identify(self, expected_id_type): + obj = {"action": "identify"} + self._server_identification = self._send_recv(obj) + if (expected_id_type is not None + and self._server_identification["type"] != expected_id_type): + raise IncompatibleServer + + def _do_rpc(self, name, args, kwargs): + obj = {"action": "call", "name": name, "args": args, "kwargs": kwargs} + obj = self._send_recv(obj) if obj["result"] == "ok": return obj["ret"] elif obj["result"] == "error": @@ -94,10 +125,16 @@ class Server: :param target: Object providing the RPC methods to be exposed to the client. + :param id_type: A string identifying the server type. Clients use it to + verify that they are connected to the proper server. + :param id_parameters: An optional human-readable string giving more + information about the parameters of the server. """ - def __init__(self, target): + def __init__(self, target, id_type, id_parameters=None): self.target = target + self.id_type = id_type + self.id_parameters = id_parameters self._client_tasks = set() @asyncio.coroutine @@ -156,22 +193,25 @@ class Server: "traceback": traceback.format_exc()} line = pyon.encode(obj) + "\n" writer.write(line.encode()) + elif action == "identify": + obj = {"type": self.id_type} + if self.id_parameters is not None: + obj["parameters"] = self.id_parameters + line = pyon.encode(obj) + "\n" + writer.write(line.encode()) finally: writer.close() -def simple_server_loop(target, host, port): +def simple_server_loop(target, id_type, host, port, id_parameters=None): """Runs a server until an exception is raised (e.g. the user hits Ctrl-C). - :param target: Object providing the RPC methods to be exposed to the - client. - :param host: Bind address of the server. - :param port: TCP port to bind to. + See ``Server`` for a description of the parameters. """ loop = asyncio.get_event_loop() try: - server = Server(target) + server = Server(target, id_type, id_parameters) loop.run_until_complete(server.start(host, port)) try: loop.run_forever() diff --git a/doc/manual/writing_a_driver.rst b/doc/manual/writing_a_driver.rst index 808f71871..df2c16ba6 100644 --- a/doc/manual/writing_a_driver.rst +++ b/doc/manual/writing_a_driver.rst @@ -23,7 +23,7 @@ To turn it into a server, we use :class:`artiq.management.pc_rpc`. Import the fu and add a ``main`` function that is run when the program is executed: :: def main(): - simple_server_loop(Hello(), "::1", 7777) + simple_server_loop(Hello(), "hello", "::1", 7777) if __name__ == "__main__": main() @@ -49,6 +49,11 @@ and verify that you can connect to the TCP port: :: :tip: Use the key combination Ctrl-AltGr-9 to get the ``telnet>`` prompt, and enter ``close`` to quit Telnet. Quit the controller with Ctrl-C. +Also verify that you can get the type of the server (the "hello" string passed to ``simple_server_loop``) using the ``identify-controller`` program from the ARTIQ front-end tools: :: + + ./identify-controller ::1 7777 + Type: hello + The client ---------- @@ -62,7 +67,7 @@ Create a ``hello-client`` file with the following contents: :: def main(): - remote = Client("::1", 7777) + remote = Client("::1", 7777, "hello") try: remote.message("Hello World!") finally: diff --git a/frontend/artiq b/frontend/artiq index 3dd78875f..41ea7e01a 100755 --- a/frontend/artiq +++ b/frontend/artiq @@ -22,7 +22,7 @@ def _get_args(): def main(): args = _get_args() - remote = Client(args.server, args.port) + remote = Client(args.server, args.port, "master") try: for path, name, timeout in args.run_once: remote.run_once( diff --git a/frontend/artiqd b/frontend/artiqd index ceefd87ca..1006fdab9 100755 --- a/frontend/artiqd +++ b/frontend/artiqd @@ -25,7 +25,7 @@ def main(): scheduler = Scheduler() loop.run_until_complete(scheduler.start()) try: - server = Server(scheduler) + server = Server(scheduler, "master") loop.run_until_complete(server.start(args.bind, args.port)) try: loop.run_forever() diff --git a/frontend/identify-controller b/frontend/identify-controller new file mode 100755 index 000000000..0b4df1d07 --- /dev/null +++ b/frontend/identify-controller @@ -0,0 +1,30 @@ +#!/usr/bin/env python3 + +import argparse + +from artiq.management.pc_rpc import Client + + +def _get_args(): + parser = argparse.ArgumentParser( + description="ARTIQ controller identification tool") + parser.add_argument("server", + help="hostname or IP of the controller to connect to") + parser.add_argument("port", type=int, + help="TCP port to use to connect to the controller") + return parser.parse_args() + + +def main(): + args = _get_args() + remote = Client(args.server, args.port, None) + try: + ident = remote.get_rpc_id() + finally: + remote.close_rpc() + print("Type: " + ident["type"]) + if "parameters" in ident: + print("Parameters: " + ident["parameters"]) + +if __name__ == "__main__": + main() diff --git a/test/pc_rpc.py b/test/pc_rpc.py index db91086d8..2528954ab 100644 --- a/test/pc_rpc.py +++ b/test/pc_rpc.py @@ -25,7 +25,8 @@ class RPCCase(unittest.TestCase): for attempt in range(100): time.sleep(.2) try: - remote = pc_rpc.Client(test_address, test_port) + remote = pc_rpc.Client(test_address, test_port, + "test") except ConnectionRefusedError: pass else: @@ -65,7 +66,7 @@ def run_server(): loop = asyncio.get_event_loop() try: echo = Echo() - server = pc_rpc.Server(echo) + server = pc_rpc.Server(echo, "test") loop.run_until_complete(server.start(test_address, test_port)) try: loop.run_until_complete(echo.wait_quit())