"""
Scrapy Telnet Console extension
See documentation in docs/topics/telnetconsole.rst
"""
from __future__ import annotations
import binascii
import logging
import os
import pprint
import traceback
from typing import TYPE_CHECKING, Any, Dict, List
from twisted.internet import protocol
from twisted.internet.tcp import Port
try:
from twisted.conch import manhole, telnet
from twisted.conch.insults import insults
TWISTED_CONCH_AVAILABLE = True
except (ImportError, SyntaxError):
_TWISTED_CONCH_TRACEBACK = traceback.format_exc()
TWISTED_CONCH_AVAILABLE = False
from scrapy import signals
from scrapy.crawler import Crawler
from scrapy.exceptions import NotConfigured
from scrapy.utils.decorators import defers
from scrapy.utils.engine import print_engine_status
from scrapy.utils.reactor import listen_tcp
from scrapy.utils.trackref import print_live_refs
if TYPE_CHECKING:
# typing.Self requires Python 3.11
from typing_extensions import Self
logger = logging.getLogger(__name__)
# signal to update telnet variables
# args: telnet_vars
update_telnet_vars = object()
[docs]class TelnetConsole(protocol.ServerFactory):
def __init__(self, crawler: Crawler):
if not crawler.settings.getbool("TELNETCONSOLE_ENABLED"):
raise NotConfigured
if not TWISTED_CONCH_AVAILABLE:
raise NotConfigured(
"TELNETCONSOLE_ENABLED setting is True but required twisted "
"modules failed to import:\n" + _TWISTED_CONCH_TRACEBACK
)
self.crawler: Crawler = crawler
self.noisy: bool = False
self.portrange: List[int] = [
int(x) for x in crawler.settings.getlist("TELNETCONSOLE_PORT")
]
self.host: str = crawler.settings["TELNETCONSOLE_HOST"]
self.username: str = crawler.settings["TELNETCONSOLE_USERNAME"]
self.password: str = crawler.settings["TELNETCONSOLE_PASSWORD"]
if not self.password:
self.password = binascii.hexlify(os.urandom(8)).decode("utf8")
logger.info("Telnet Password: %s", self.password)
self.crawler.signals.connect(self.start_listening, signals.engine_started)
self.crawler.signals.connect(self.stop_listening, signals.engine_stopped)
@classmethod
def from_crawler(cls, crawler: Crawler) -> Self:
return cls(crawler)
def start_listening(self) -> None:
self.port: Port = listen_tcp(self.portrange, self.host, self)
h = self.port.getHost()
logger.info(
"Telnet console listening on %(host)s:%(port)d",
{"host": h.host, "port": h.port},
extra={"crawler": self.crawler},
)
def stop_listening(self) -> None:
self.port.stopListening()
def protocol(self) -> telnet.TelnetTransport: # type: ignore[override]
class Portal:
"""An implementation of IPortal"""
@defers
def login(self_, credentials, mind, *interfaces):
if not (
credentials.username == self.username.encode("utf8")
and credentials.checkPassword(self.password.encode("utf8"))
):
raise ValueError("Invalid credentials")
protocol = telnet.TelnetBootstrapProtocol(
insults.ServerProtocol, manhole.Manhole, self._get_telnet_vars()
)
return (interfaces[0], protocol, lambda: None)
return telnet.TelnetTransport(telnet.AuthenticatingTelnetProtocol, Portal())
def _get_telnet_vars(self) -> Dict[str, Any]:
# Note: if you add entries here also update topics/telnetconsole.rst
assert self.crawler.engine
telnet_vars: Dict[str, Any] = {
"engine": self.crawler.engine,
"spider": self.crawler.engine.spider,
"slot": self.crawler.engine.slot,
"crawler": self.crawler,
"extensions": self.crawler.extensions,
"stats": self.crawler.stats,
"settings": self.crawler.settings,
"est": lambda: print_engine_status(self.crawler.engine),
"p": pprint.pprint,
"prefs": print_live_refs,
"help": "This is Scrapy telnet console. For more info see: "
"https://docs.scrapy.org/en/latest/topics/telnetconsole.html",
}
self.crawler.signals.send_catch_log(update_telnet_vars, telnet_vars=telnet_vars)
return telnet_vars