src/nominatim_api/server/starlette/server.py

   1 # SPDX-License-Identifier: GPL-3.0-or-later
   2 #
   3 # This file is part of Nominatim. (https://nominatim.org)
   4 #
   5 # Copyright (C) 2024 by the Nominatim developer community.
   6 # For a full list of authors see the git log.
   7 """
   8 Server implementation using the starlette webserver framework.
   9 """
  10 from typing import Any, Optional, Mapping, Callable, cast, Coroutine, Dict, Awaitable
  11 from pathlib import Path
  12 import datetime as dt
  13 import asyncio
  14
  15 from starlette.applications import Starlette
  16 from starlette.routing import Route
  17 from starlette.exceptions import HTTPException
  18 from starlette.responses import Response, PlainTextResponse, HTMLResponse
  19 from starlette.requests import Request
  20 from starlette.middleware import Middleware
  21 from starlette.middleware.base import BaseHTTPMiddleware, RequestResponseEndpoint
  22 from starlette.middleware.cors import CORSMiddleware
  23
  24 from nominatim_core.config import Configuration
  25 from ...core import NominatimAPIAsync
  26 from ... import v1 as api_impl
  27 from ... import logging as loglib
  28
  29 class ParamWrapper(api_impl.ASGIAdaptor):
  30     """ Adaptor class for server glue to Starlette framework.
  31     """
  32
  33     def __init__(self, request: Request) -> None:
  34         self.request = request
  35
  36
  37     def get(self, name: str, default: Optional[str] = None) -> Optional[str]:
  38         return self.request.query_params.get(name, default=default)
  39
  40
  41     def get_header(self, name: str, default: Optional[str] = None) -> Optional[str]:
  42         return self.request.headers.get(name, default)
  43
  44
  45     def error(self, msg: str, status: int = 400) -> HTTPException:
  46         return HTTPException(status, detail=msg,
  47                              headers={'content-type': self.content_type})
  48
  49
  50     def create_response(self, status: int, output: str, num_results: int) -> Response:
  51         self.request.state.num_results = num_results
  52         return Response(output, status_code=status, media_type=self.content_type)
  53
  54
  55     def base_uri(self) -> str:
  56         scheme = self.request.url.scheme
  57         host = self.request.url.hostname
  58         port = self.request.url.port
  59         root = self.request.scope['root_path']
  60         if (scheme == 'http' and port == 80) or (scheme == 'https' and port == 443):
  61             port = None
  62         if port is not None:
  63             return f"{scheme}://{host}:{port}{root}"
  64
  65         return f"{scheme}://{host}{root}"
  66
  67
  68     def config(self) -> Configuration:
  69         return cast(Configuration, self.request.app.state.API.config)
  70
  71
  72 def _wrap_endpoint(func: api_impl.EndpointFunc)\
  73         -> Callable[[Request], Coroutine[Any, Any, Response]]:
  74     async def _callback(request: Request) -> Response:
  75         return cast(Response, await func(request.app.state.API, ParamWrapper(request)))
  76
  77     return _callback
  78
  79
  80 class FileLoggingMiddleware(BaseHTTPMiddleware):
  81     """ Middleware to log selected requests into a file.
  82     """
  83
  84     def __init__(self, app: Starlette, file_name: str = ''):
  85         super().__init__(app)
  86         self.fd = open(file_name, 'a', buffering=1, encoding='utf8') # pylint: disable=R1732
  87
  88     async def dispatch(self, request: Request,
  89                        call_next: RequestResponseEndpoint) -> Response:
  90         start = dt.datetime.now(tz=dt.timezone.utc)
  91         response = await call_next(request)
  92
  93         if response.status_code != 200:
  94             return response
  95
  96         finish = dt.datetime.now(tz=dt.timezone.utc)
  97
  98         for endpoint in ('reverse', 'search', 'lookup', 'details'):
  99             if request.url.path.startswith('/' + endpoint):
 100                 qtype = endpoint
 101                 break
 102         else:
 103             return response
 104
 105         duration = (finish - start).total_seconds()
 106         params = request.scope['query_string'].decode('utf8')
 107
 108         self.fd.write(f"[{start.replace(tzinfo=None).isoformat(sep=' ', timespec='milliseconds')}] "
 109                       f"{duration:.4f} {getattr(request.state, 'num_results', 0)} "
 110                       f'{qtype} "{params}"\n')
 111
 112         return response
 113
 114
 115 async def timeout_error(request: Request, #pylint: disable=unused-argument
 116                         _: Exception) -> Response:
 117     """ Error handler for query timeouts.
 118     """
 119     loglib.log().comment('Aborted: Query took too long to process.')
 120     logdata = loglib.get_and_disable()
 121
 122     if logdata:
 123         return HTMLResponse(logdata)
 124
 125     return PlainTextResponse("Query took too long to process.", status_code=503)
 126
 127
 128 def get_application(project_dir: Path,
 129                     environ: Optional[Mapping[str, str]] = None,
 130                     debug: bool = True) -> Starlette:
 131     """ Create a Nominatim falcon ASGI application.
 132     """
 133     config = Configuration(project_dir, environ)
 134
 135     routes = []
 136     legacy_urls = config.get_bool('SERVE_LEGACY_URLS')
 137     for name, func in api_impl.ROUTES:
 138         endpoint = _wrap_endpoint(func)
 139         routes.append(Route(f"/{name}", endpoint=endpoint))
 140         if legacy_urls:
 141             routes.append(Route(f"/{name}.php", endpoint=endpoint))
 142
 143     middleware = []
 144     if config.get_bool('CORS_NOACCESSCONTROL'):
 145         middleware.append(Middleware(CORSMiddleware,
 146                                      allow_origins=['*'],
 147                                      allow_methods=['GET', 'OPTIONS'],
 148                                      max_age=86400))
 149
 150     log_file = config.LOG_FILE
 151     if log_file:
 152         middleware.append(Middleware(FileLoggingMiddleware, file_name=log_file))
 153
 154     exceptions: Dict[Any, Callable[[Request, Exception], Awaitable[Response]]] = {
 155         TimeoutError: timeout_error,
 156         asyncio.TimeoutError: timeout_error
 157     }
 158
 159     async def _shutdown() -> None:
 160         await app.state.API.close()
 161
 162     app = Starlette(debug=debug, routes=routes, middleware=middleware,
 163                     exception_handlers=exceptions,
 164                     on_shutdown=[_shutdown])
 165
 166     app.state.API = NominatimAPIAsync(project_dir, environ)
 167
 168     return app
 169
 170
 171 def run_wsgi() -> Starlette:
 172     """ Entry point for uvicorn.
 173     """
 174     return get_application(Path('.'), debug=False)