Files
crucible-agent-build-fastap…/app/checker.py

98 lines
3.7 KiB
Python

import logging
import time
from urllib.parse import urljoin
import httpx
from app.config import Settings
from app.models import CurrentStatus, MonitorState, utc_now
from app.security import Resolver, UnsafeTarget, redact_url, system_resolver, validate_target
logger = logging.getLogger("endpoint_monitor.checker")
_REDIRECTS = {301, 302, 303, 307, 308}
class EndpointChecker:
def __init__(
self,
settings: Settings,
*,
transport: httpx.AsyncBaseTransport | None = None,
resolver: Resolver = system_resolver,
) -> None:
self.settings = settings
self.transport = transport
self.resolver = resolver
async def check(self, monitor_id: str, target_url: str) -> CurrentStatus:
started = time.monotonic()
current_url = target_url
timeout = httpx.Timeout(
connect=self.settings.connect_timeout_seconds,
read=self.settings.read_timeout_seconds,
write=self.settings.write_timeout_seconds,
pool=self.settings.pool_timeout_seconds,
)
limits = httpx.Limits(max_connections=self.settings.max_connections)
try:
async with httpx.AsyncClient(
timeout=timeout,
limits=limits,
transport=self.transport,
follow_redirects=False,
headers={"User-Agent": self.settings.user_agent},
) as client:
for redirect_count in range(self.settings.max_redirects + 1):
await validate_target(current_url, self.resolver)
async with client.stream("GET", current_url) as response:
if response.status_code in _REDIRECTS and response.headers.get("location"):
if redirect_count >= self.settings.max_redirects:
raise httpx.TooManyRedirects("redirect limit exceeded")
current_url = urljoin(current_url, response.headers["location"])
continue
state = MonitorState.UP if response.status_code < 400 else MonitorState.DOWN
result = self._status(started, state, response.status_code)
self._log(monitor_id, current_url, result)
return result
except UnsafeTarget:
logger.warning(
"check blocked",
extra={"event": "check_blocked", "monitor_id": monitor_id, "url": redact_url(current_url)},
)
raise
except (httpx.HTTPError, OSError) as exc:
result = self._status(started, MonitorState.ERROR, error=str(exc)[:500])
self._log(monitor_id, current_url, result)
return result
raise RuntimeError("unreachable redirect loop")
@staticmethod
def _status(
started: float,
state: MonitorState,
http_status: int | None = None,
error: str | None = None,
) -> CurrentStatus:
return CurrentStatus(
state=state,
checked_at=utc_now(),
latency_ms=round((time.monotonic() - started) * 1000, 3),
http_status=http_status,
error=error,
)
@staticmethod
def _log(monitor_id: str, url: str, result: CurrentStatus) -> None:
logger.info(
"check completed",
extra={
"event": "check_completed",
"monitor_id": monitor_id,
"url": redact_url(url),
"outcome": result.state.value,
"latency_ms": result.latency_ms,
"http_status": result.http_status,
"error": result.error,
},
)