# Copyright (c) 2016 Weitian LI # MIT license """ Communicate with the "fg21sim" simulation program through the Web UI using the WebSocket_ protocol, which provides full-duplex communication channels over a single TCP connection. .. _WebSocket: https://en.wikipedia.org/wiki/WebSocket References ---------- - Tornado WebSocket: http://www.tornadoweb.org/en/stable/websocket.html - Can I Use: WebSocket: http://caniuse.com/#feat=websockets """ import os import json import logging import tornado.websocket from tornado.options import options from .consolehandler import ConsoleHandler from .utils import get_host_ip, ip_in_network from ..configs import ConfigManager from ..errors import ConfigError logger = logging.getLogger(__name__) class FG21simWSHandler(tornado.websocket.WebSocketHandler): """ WebSocket for bi-directional communication between the Web UI and the server, which can deal with the configurations and execute the simulation task. Generally, WebSocket send and receive data as *string*. Therefore, the more complex data are stringified as JSON string before sending, which will be parsed after receive. Each message (as a JSON object or Python dictionary) has a ``type`` field which will be used to determine the following action to take. Attributes ---------- name : str Name to distinguish this WebSocket handle. from_localhost : bool Set to ``True`` if the access is from the localhost, otherwise ``False``. configs : `~ConfigManager` A ``ConfigManager`` instance, for configuration manipulations when communicating with the Web UI. """ name = "fg21sim" from_localhost = None def check_origin(self, origin): """Check the origin of the WebSocket access. Attributes ---------- from_localhost : bool Set to ``True`` if the access is from the localhost, otherwise ``False``. NOTE ---- Currently, only allow access from the ``localhost`` (i.e., 127.0.0.1) and local LAN. """ self.from_localhost = False logger.info("WebSocket: {0}: origin: {1}".format(self.name, origin)) ip = get_host_ip(url=origin) network = options.hosts_allowed if ip == "127.0.0.1": self.from_localhost = True allow = True logger.info("WebSocket: %s: origin is localhost" % self.name) elif network.upper() == "ANY": # Any hosts are allowed allow = True logger.error("WebSocket: %s: any hosts are allowed" % self.name) elif ip_in_network(ip, network): allow = True logger.error("WebSocket: %s: " % self.name + "client is in the allowed network: %s" % network) else: allow = False logger.error("WebSocket: %s: " % self.name + "client is NOT in the allowed network: %s" % network) return allow def open(self): """Invoked when a new WebSocket is opened by the client.""" # FIXME: # * better to move to the `Application` class ?? # * or create a ``ConfigsHandler`` similar to the ``ConsoleHandler`` self.configs = ConfigManager() self.console_handler = ConsoleHandler(websocket=self) # logger.info("WebSocket: {0}: opened".format(self.name)) logger.info("Allowed hosts: {0}".format(options.hosts_allowed)) def on_close(self): """Invoked when a new WebSocket is closed by the client.""" code, reason = None, None if hasattr(self, "close_code"): code = self.close_code if hasattr(self, "close_reason"): reason = self.close_reason logger.info("WebSocket: {0}: closed by client: {1}, {2}".format( self.name, code, reason)) # FIXME/XXX: # * How to be non-blocking ?? # NOTE: WebSocket.on_message: may NOT be a coroutine at the moment (v4.3) # References: # [1] https://stackoverflow.com/a/35543856/4856091 # [2] https://stackoverflow.com/a/33724486/4856091 def on_message(self, message): """Handle incoming messages and dispatch task according to the message type. NOTE ---- The received message (parsed to a Python dictionary) has a ``type`` item which will be used to determine the following action to take. Currently supported message types are: ``configs``: Request or set the configurations ``console``: Control the simulation tasks, or request logging messages ``results``: Request the simulation results The sent message also has a ``type`` item of same value, which the client can be used to figure out the proper actions. There is a ``success`` item which indicates the status of the requested operation, and an ``error`` recording the error message if ``success=False``. """ logger.debug("WebSocket: %s: received: %s" % (self.name, message)) try: msg = json.loads(message) msg_type = msg["type"] except json.JSONDecodeError: logger.warning("WebSocket: {0}: ".format(self.name) + "message is not a valid JSON string") response = {"success": False, "type": None, "error": "message is not a valid JSON string"} except (KeyError, TypeError): logger.warning("WebSocket: %s: skip invalid message" % self.name) response = {"success": False, "type": None, "error": "type is missing"} else: # Check the message type and dispatch task if msg_type == "configs": # Request or set the configurations response = self._handle_configs(msg) elif msg_type == "console": # Control the simulation tasks, or request logging messages # FIXME/XXX: # * How to make this asynchronously ?? response = self.console_handler.handle_message(msg) elif msg_type == "results": # Request the simulation results response = self._handle_results(msg) else: # Message of unknown type logger.warning("WebSocket: {0}: ".format(self.name) + "unknown message type: {0}".format(msg_type)) response = {"success": False, "type": msg_type, "error": "unknown message type %s" % msg_type} # msg_response = json.dumps(response) self.write_message(msg_response) def _handle_configs(self, msg): """Handle the message of type "configs", which request to get or set some configurations by the client. TODO: * improve the description ... * split these handling functions into a separate class in a module Parameters ---------- msg : dict A dictionary parsed from the incoming JSON message, which generally has the following syntax: ``{"type": "configs", "action": , "data": }`` where the ```` is ``set`` or ``get``, and the ```` is a list of config keys or a dict of config key-value pairs. Returns ------- response : dict A dictionary parsed from the incoming JSON message, which generally has the following syntax: ``{"type": "configs", "action": , "data": , "errors": }`` where the ```` is the same as input, the ```` is a list of config keys or a dict of config key-value pairs, and ```` contains the error message for the invalid config values. """ try: msg_type = msg["type"] msg_action = msg["action"] response = {"type": msg_type, "action": msg_action} logger.info("WebSocket: {0}: handle message: ".format(self.name) + "type: {0}, action: {1}".format(msg_type, msg_action)) if msg_action == "get": # Get the values of the specified options try: data, errors = self._get_configs(keys=msg["keys"]) response["success"] = True response["data"] = data response["errors"] = errors except KeyError: response["success"] = False response["error"] = "'keys' is missing" elif msg_action == "set": # Set the values of the specified options try: errors = self._set_configs(data=msg["data"]) response["success"] = True response["data"] = {} # be more consistent response["errors"] = errors except KeyError: response["success"] = False response["error"] = "'data' is missing" elif msg_action == "reset": # Reset the configurations to the defaults self._reset_configs() response["success"] = True elif msg_action == "load": # Load the supplied user configuration file try: success, error = self._load_configs(msg["userconfig"]) response["success"] = success if not success: response["error"] = error except KeyError: response["success"] = False response["error"] = "'userconfig' is missing" elif msg_action == "save": # Save current configurations to file try: success, error = self._save_configs(msg["outfile"], msg["clobber"]) response["success"] = success if not success: response["error"] = error except KeyError: response["success"] = False response["error"] = "'outfile' or 'clobber' is missing" else: logger.warning("WebSocket: {0}: ".format(self.name) + "unknown action: {0}".format(msg_action)) response["success"] = False response["error"] = "unknown action: {0}".format(msg_action) except KeyError: # Received message has wrong syntax/format response = {"success": False, "type": msg_type, "error": "no action specified"} # logger.debug("WebSocket: {0}: ".format(self.name) + "response: {0}".format(response)) return response def _get_configs(self, keys=None): """Get the values of the config options specified by the given keys. Parameters ---------- keys : list[str], optional A list of keys specifying the config options whose values will be obtained. If ``keys=None``, then all the configurations values are dumped. Returns ------- data : dict A dictionary with keys the same as the input keys, and values the corresponding config option values. errors : dict When error occurs (e.g., invalid key), then the specific errors with details are stored in this dictionary. NOTE ---- Do not forget the ``userconfig`` option. """ if keys is None: # Dump all the configurations data = self.configs.dump(flatten=True) data["userconfig"] = self.configs.userconfig errors = {} else: data = {} errors = {} for key in keys: if key == "userconfig": data["userconfig"] = self.configs.userconfig else: try: data[key] = self.configs.getn(key) except KeyError as e: errors[key] = str(e) # return (data, errors) def _set_configs(self, data): """Set the values of the config options specified by the given keys to the corresponding supplied data. NOTE ---- The ``userconfig`` and ``workdir`` options are ignored. Parameters ---------- data : dict A dictionary of key-value pairs, with keys specifying the config options whose value will be changed, and values the new values to which config options will be set. NOTE: If want to set the ``userconfig`` option, an *absolute path* must be provided (i.e., client should take care of the ``workdir`` value and generate a absolute path for ``userconfig``). Returns ------- errors : dict When error occurs (e.g., invalid key, invalid values), then the specific errors with details are stored in this dictionary. """ errors = {} for key, value in data.items(): if key in ["userconfig", "workdir"]: # Ignore "userconfig" and "workdir" continue else: try: self.configs.setn(key, value) except KeyError as e: errors[key] = str(e) # NOTE: # Check the whole configurations after all provided options are # updated, and merge the validation errors. __, cherr = self.configs.check_all(raise_exception=False) errors.update(cherr) return errors def _reset_configs(self): """Reset the configurations to the defaults.""" self.configs.reset() def _load_configs(self, userconfig): """Load configurations from the provided user configuration file. Parameters ---------- userconfig: str The filepath to the user configuration file, which must be an *absolute path*. Returns ------- success : bool ``True`` if the operation succeeded, otherwise, ``False``. error : str If failed, this ``error`` saves the details, otherwise, ``None``. """ success = False error = None if os.path.isabs(userconfig): try: self.configs.read_userconfig(userconfig) success = True except ConfigError as e: error = str(e) else: error = "Not an absolute path" return (success, error) def _save_configs(self, outfile, clobber=False): """Save current configurations to file. Parameters ---------- outfile: str The filepath to the output configuration file, which must be an *absolute path*. clobber : bool, optional Whether overwrite the output file if already exists? Returns ------- success : bool ``True`` if the operation succeeded, otherwise, ``False``. error : str If failed, this ``error`` saves the details, otherwise, ``None``. """ success = False error = None try: self.configs.save(outfile, clobber=clobber) success = True except (ValueError, OSError) as e: error = str(e) return (success, error) def _handle_results(self, msg): # Got a message of supported types msg_type = msg["type"] logger.info("WebSocket: {0}: ".format(self.name) + "handle message of type: {0}".format(msg_type)) response = {"success": True, "type": msg_type} return response