tabpy.tabpy_server.app.app

Complexity

Total Complexity

52

Size/Duplication

Total Lines	434
Duplicated Lines	0 %

Test Coverage

Coverage

81.68%

Importance

Changes

0

10 Methods

Rating	Name	Duplication	Size	Complexity
A	TabPyApp._parse_pwd_file()	0	10	3
B	TabPyApp._validate_cert_key_state()	0	18	6
B	TabPyApp._set_parameter()	0	29	8
A	TabPyApp.__init__()	0	14	4
A	TabPyApp._validate_transfer_protocol_settings()	0	29	4
D	TabPyApp._parse_config()	0	132	11
B	TabPyApp._create_tornado_web_app()	0	70	3
A	TabPyApp.run()	0	33	3
A	TabPyApp._get_features()	0	11	2
A	TabPyApp._build_tabpy_state()	0	17	2

import concurrent.futures
import configparser
import logging
import multiprocessing
import os
import shutil
import signal
import sys
import tabpy
from tabpy.tabpy import __version__
from tabpy.tabpy_server.app.app_parameters import ConfigParameters, SettingsParameters
from tabpy.tabpy_server.app.util import parse_pwd_file
from tabpy.tabpy_server.management.state import TabPyState
from tabpy.tabpy_server.management.util import _get_state_from_file
from tabpy.tabpy_server.psws.callbacks import init_model_evaluator, init_ps_server
from tabpy.tabpy_server.psws.python_service import PythonService, PythonServiceHandler
from tabpy.tabpy_server.handlers import (
    EndpointHandler,
    EndpointsHandler,
    EvaluationPlaneHandler,
    QueryPlaneHandler,
    ServiceInfoHandler,
    StatusHandler,
    UploadDestinationHandler,
)
import tornado


logger = logging.getLogger(__name__)


def _init_asyncio_patch():
    """
    Select compatible event loop for Tornado 5+.
    As of Python 3.8, the default event loop on Windows is `proactor`,
    however Tornado requires the old default "selector" event loop.
    As Tornado has decided to leave this to users to set, MkDocs needs
    to set it. See https://github.com/tornadoweb/tornado/issues/2608.
    """
    if sys.platform.startswith("win") and sys.version_info >= (3, 8):
        import asyncio
        try:
            from asyncio import WindowsSelectorEventLoopPolicy
        except ImportError:
            pass  # Can't assign a policy which doesn't exist.
        else:
            if not isinstance(asyncio.get_event_loop_policy(), WindowsSelectorEventLoopPolicy):
                asyncio.set_event_loop_policy(WindowsSelectorEventLoopPolicy())


class TabPyApp:
    """
    TabPy application class for keeping context like settings, state, etc.
    """

    settings = {}
    subdirectory = ""
    tabpy_state = None
    python_service = None
    credentials = {}

    def __init__(self, config_file):
        if config_file is None:
            config_file = os.path.join(
                os.path.dirname(__file__), os.path.pardir, "common", "default.conf"
            )

        if os.path.isfile(config_file):
            try:
                from logging import config
                config.fileConfig(config_file, disable_existing_loggers=False)
            except KeyError:
                logging.basicConfig(level=logging.DEBUG)

        self._parse_config(config_file)

    def run(self):
        application = self._create_tornado_web_app()
        max_request_size = (
            int(self.settings[SettingsParameters.MaxRequestSizeInMb]) * 1024 * 1024
        )
        logger.info(f"Setting max request size to {max_request_size} bytes")

        init_model_evaluator(self.settings, self.tabpy_state, self.python_service)

        protocol = self.settings[SettingsParameters.TransferProtocol]
        ssl_options = None
        if protocol == "https":
            ssl_options = {
                "certfile": self.settings[SettingsParameters.CertificateFile],
                "keyfile": self.settings[SettingsParameters.KeyFile],
            }
        elif protocol != "http":
            msg = f"Unsupported transfer protocol {protocol}."
            logger.critical(msg)
            raise RuntimeError(msg)

        application.listen(
            self.settings[SettingsParameters.Port],
            ssl_options=ssl_options,
            max_buffer_size=max_request_size,
            max_body_size=max_request_size,
        )

        logger.info(
            "Web service listening on port "
            f"{str(self.settings[SettingsParameters.Port])}"
        )
        tornado.ioloop.IOLoop.instance().start()

    def _create_tornado_web_app(self):
        class TabPyTornadoApp(tornado.web.Application):
            is_closing = False

            def signal_handler(self, signal, _):
                logger.critical(f"Exiting on signal {signal}...")
                self.is_closing = True

            def try_exit(self):
                if self.is_closing:
                    tornado.ioloop.IOLoop.instance().stop()
                    logger.info("Shutting down TabPy...")

        logger.info("Initializing TabPy...")
        tornado.ioloop.IOLoop.instance().run_sync(
            lambda: init_ps_server(self.settings, self.tabpy_state)
        )
        logger.info("Done initializing TabPy.")

        executor = concurrent.futures.ThreadPoolExecutor(
            max_workers=multiprocessing.cpu_count()
        )

        # initialize Tornado application
        _init_asyncio_patch()
        application = TabPyTornadoApp(
            [
                (
                    self.subdirectory + r"/query/([^/]+)",
                    QueryPlaneHandler,
                    dict(app=self),
                ),
                (self.subdirectory + r"/status", StatusHandler, dict(app=self)),
                (self.subdirectory + r"/info", ServiceInfoHandler, dict(app=self)),
                (self.subdirectory + r"/endpoints", EndpointsHandler, dict(app=self)),
                (
                    self.subdirectory + r"/endpoints/([^/]+)?",
                    EndpointHandler,
                    dict(app=self),
                ),
                (
                    self.subdirectory + r"/evaluate",
                    EvaluationPlaneHandler,
                    dict(executor=executor, app=self),
                ),
                (
                    self.subdirectory + r"/configurations/endpoint_upload_destination",
                    UploadDestinationHandler,
                    dict(app=self),
                ),
                (
                    self.subdirectory + r"/(.*)",
                    tornado.web.StaticFileHandler,
                    dict(
                        path=self.settings[SettingsParameters.StaticPath],
                        default_filename="index.html",
                    ),
                ),
            ],
            debug=False,
            **self.settings,
        )

        signal.signal(signal.SIGINT, application.signal_handler)
        tornado.ioloop.PeriodicCallback(application.try_exit, 500).start()

        signal.signal(signal.SIGINT, application.signal_handler)
        tornado.ioloop.PeriodicCallback(application.try_exit, 500).start()

        return application

    def _set_parameter(self, parser, settings_key, config_key, default_val, parse_function):
        key_is_set = False

        if (
            config_key is not None
            and parser.has_section("TabPy")
            and parser.has_option("TabPy", config_key)
        ):
            if parse_function is None:
                parse_function = parser.get
            self.settings[settings_key] = parse_function("TabPy", config_key)
            key_is_set = True
            logger.debug(
                f"Parameter {settings_key} set to "
                f'"{self.settings[settings_key]}" '
                "from config file or environment variable"
            )

        if not key_is_set and default_val is not None:
            self.settings[settings_key] = default_val
            key_is_set = True
            logger.debug(
                f"Parameter {settings_key} set to "
                f'"{self.settings[settings_key]}" '
                "from default value"
            )

        if not key_is_set:
            logger.debug(f"Parameter {settings_key} is not set")

    def _parse_config(self, config_file):
        """Provide consistent mechanism for pulling in configuration.

        Attempt to retain backward compatibility for
        existing implementations by grabbing port
        setting from CLI first.

        Take settings in the following order:

        1. CLI arguments if present
        2. config file
        3. OS environment variables (for ease of
           setting defaults if not present)
        4. current defaults if a setting is not present in any location

        Additionally provide similar configuration capabilities in between
        config file and environment variables.
        For consistency use the same variable name in the config file as
        in the os environment.
        For naming standards use all capitals and start with 'TABPY_'
        """
        self.settings = {}
        self.subdirectory = ""
        self.tabpy_state = None
        self.python_service = None
        self.credentials = {}

        pkg_path = os.path.dirname(tabpy.__file__)

        parser = configparser.ConfigParser(os.environ)
        logger.info(f"Parsing config file {config_file}")

        file_exists = False
        if os.path.isfile(config_file):
            try:
                with open(config_file, 'r') as f:
                    parser.read_string(f.read())
                    file_exists = True
            except Exception:
                pass

        if not file_exists:
            logger.warning(
                f"Unable to open config file {config_file}, "
                "using default settings."
            )

        settings_parameters = [
            (SettingsParameters.Port, ConfigParameters.TABPY_PORT, 9004, None),
            (SettingsParameters.ServerVersion, None, __version__, None),
            (SettingsParameters.EvaluateTimeout, ConfigParameters.TABPY_EVALUATE_TIMEOUT,
             30, parser.getfloat),
            (SettingsParameters.UploadDir, ConfigParameters.TABPY_QUERY_OBJECT_PATH,
             os.path.join(pkg_path, "tmp", "query_objects"), None),
            (SettingsParameters.TransferProtocol, ConfigParameters.TABPY_TRANSFER_PROTOCOL,
             "http", None),
            (SettingsParameters.CertificateFile, ConfigParameters.TABPY_CERTIFICATE_FILE,
             None, None),
            (SettingsParameters.KeyFile, ConfigParameters.TABPY_KEY_FILE, None, None),
            (SettingsParameters.StateFilePath, ConfigParameters.TABPY_STATE_PATH,
             os.path.join(pkg_path, "tabpy_server"), None),
            (SettingsParameters.StaticPath, ConfigParameters.TABPY_STATIC_PATH,
             os.path.join(pkg_path, "tabpy_server", "static"), None),
            (ConfigParameters.TABPY_PWD_FILE, ConfigParameters.TABPY_PWD_FILE, None, None),
            (SettingsParameters.LogRequestContext, ConfigParameters.TABPY_LOG_DETAILS,
             "false", None),
            (SettingsParameters.MaxRequestSizeInMb, ConfigParameters.TABPY_MAX_REQUEST_SIZE_MB,
             100, None),
        ]

        for setting, parameter, default_val, parse_function in settings_parameters:
            self._set_parameter(parser, setting, parameter, default_val, parse_function)

        if not os.path.exists(self.settings[SettingsParameters.UploadDir]):
            os.makedirs(self.settings[SettingsParameters.UploadDir])

        # set and validate transfer protocol
        self.settings[SettingsParameters.TransferProtocol] = self.settings[
            SettingsParameters.TransferProtocol
        ].lower()

        self._validate_transfer_protocol_settings()

        # if state.ini does not exist try and create it - remove
        # last dependence on batch/shell script
        self.settings[SettingsParameters.StateFilePath] = os.path.realpath(
            os.path.normpath(
                os.path.expanduser(self.settings[SettingsParameters.StateFilePath])
            )
        )
        state_config, self.tabpy_state = self._build_tabpy_state()

        self.python_service = PythonServiceHandler(PythonService())
        self.settings["compress_response"] = True
        self.settings[SettingsParameters.StaticPath] = os.path.abspath(
            self.settings[SettingsParameters.StaticPath]
        )
        logger.debug(
            f"Static pages folder set to "
            f'"{self.settings[SettingsParameters.StaticPath]}"'
        )

        # Set subdirectory from config if applicable
        if state_config.has_option("Service Info", "Subdirectory"):
            self.subdirectory = "/" + state_config.get("Service Info", "Subdirectory")

        # If passwords file specified load credentials
        if ConfigParameters.TABPY_PWD_FILE in self.settings:
            if not self._parse_pwd_file():
                msg = (
                    "Failed to read passwords file "
                    f"{self.settings[ConfigParameters.TABPY_PWD_FILE]}"
                )
                logger.critical(msg)
                raise RuntimeError(msg)
        else:
            logger.info(
                "Password file is not specified: " "Authentication is not enabled"
            )

        features = self._get_features()
        self.settings[SettingsParameters.ApiVersions] = {"v1": {"features": features}}

        self.settings[SettingsParameters.LogRequestContext] = (
            self.settings[SettingsParameters.LogRequestContext].lower() != "false"
        )
        call_context_state = (
            "enabled"
            if self.settings[SettingsParameters.LogRequestContext]
            else "disabled"
        )
        logger.info(f"Call context logging is {call_context_state}")

    def _validate_transfer_protocol_settings(self):
        if SettingsParameters.TransferProtocol not in self.settings:
            msg = "Missing transfer protocol information."
            logger.critical(msg)
            raise RuntimeError(msg)

        protocol = self.settings[SettingsParameters.TransferProtocol]

        if protocol == "http":
            return

        if protocol != "https":
            msg = f"Unsupported transfer protocol: {protocol}"
            logger.critical(msg)
            raise RuntimeError(msg)

        self._validate_cert_key_state(
            "The parameter(s) {} must be set.",
            SettingsParameters.CertificateFile in self.settings,
            SettingsParameters.KeyFile in self.settings,
        )
        cert = self.settings[SettingsParameters.CertificateFile]

        self._validate_cert_key_state(
            "The parameter(s) {} must point to " "an existing file.",
            os.path.isfile(cert),
            os.path.isfile(self.settings[SettingsParameters.KeyFile]),
        )
        tabpy.tabpy_server.app.util.validate_cert(cert)

    @staticmethod
    def _validate_cert_key_state(msg, cert_valid, key_valid):
        cert_and_key_param = (
            f"{ConfigParameters.TABPY_CERTIFICATE_FILE} and "
            f"{ConfigParameters.TABPY_KEY_FILE}"
        )
        https_error = "Error using HTTPS: "
        err = None
        if not cert_valid and not key_valid:
            err = https_error + msg.format(cert_and_key_param)
        elif not cert_valid:
            err = https_error + msg.format(ConfigParameters.TABPY_CERTIFICATE_FILE)
        elif not key_valid:
            err = https_error + msg.format(ConfigParameters.TABPY_KEY_FILE)

        if err is not None:
            logger.critical(err)
            raise RuntimeError(err)

    def _parse_pwd_file(self):
        succeeded, self.credentials = parse_pwd_file(
            self.settings[ConfigParameters.TABPY_PWD_FILE]
        )

        if succeeded and len(self.credentials) == 0:
            logger.error("No credentials found")
            succeeded = False

        return succeeded

    def _get_features(self):
        features = {}

        # Check for auth
        if ConfigParameters.TABPY_PWD_FILE in self.settings:
            features["authentication"] = {
                "required": True,
                "methods": {"basic-auth": {}},
            }

        return features

    def _build_tabpy_state(self):
        pkg_path = os.path.dirname(tabpy.__file__)
        state_file_dir = self.settings[SettingsParameters.StateFilePath]
        state_file_path = os.path.join(state_file_dir, "state.ini")
        if not os.path.isfile(state_file_path):
            state_file_template_path = os.path.join(
                pkg_path, "tabpy_server", "state.ini.template"
            )
            logger.debug(
                f"File {state_file_path} not found, creating from "
                f"template {state_file_template_path}..."
            )
            shutil.copy(state_file_template_path, state_file_path)

        logger.info(f"Loading state from state file {state_file_path}")
        tabpy_state = _get_state_from_file(state_file_dir)
        return tabpy_state, TabPyState(config=tabpy_state, settings=self.settings)