Files
Keith Smith a8c160bc05 Show TLS certificate validity details
Include healthy TLS certificate validity in website check messages and show latest website check results in the UI.
2026-05-23 15:33:54 -06:00

131 lines
4.9 KiB
Python

from dataclasses import dataclass
from datetime import UTC, datetime
import asyncio
import socket
import ssl
from time import perf_counter
from urllib.parse import urlparse
import httpx
from cryptography import x509
@dataclass(frozen=True)
class WebsiteCheckConfig:
url: str
expected_status: int = 200
expected_text: str | None = None
unexpected_text: str | None = None
timeout_seconds: float = 10.0
check_tls_expiry: bool = False
tls_warning_days: int = 30
@dataclass(frozen=True)
class WebsiteCheckResult:
status: str
response_time_ms: int | None
message: str
@dataclass(frozen=True)
class TlsExpiryResult:
status: str
response_time_ms: int
message: str
async def run_website_check(config: WebsiteCheckConfig) -> WebsiteCheckResult:
started = perf_counter()
tls_message: str | None = None
if config.check_tls_expiry:
tls_result = await check_tls_expiry(config.url, config.tls_warning_days, config.timeout_seconds)
if tls_result.status != "up":
return tls_result
tls_message = tls_result.message
try:
async with httpx.AsyncClient(follow_redirects=True, timeout=config.timeout_seconds) as client:
response = await client.get(config.url)
except httpx.HTTPError as exc:
return WebsiteCheckResult(status="down", response_time_ms=None, message=str(exc))
response_time_ms = int((perf_counter() - started) * 1000)
if response.status_code != config.expected_status:
return WebsiteCheckResult(
status="down",
response_time_ms=response_time_ms,
message=f"Expected HTTP {config.expected_status}, got {response.status_code}",
)
if config.expected_text and config.expected_text not in response.text:
return WebsiteCheckResult(
status="down",
response_time_ms=response_time_ms,
message="Expected text was not present",
)
if config.unexpected_text and config.unexpected_text in response.text:
return WebsiteCheckResult(
status="down",
response_time_ms=response_time_ms,
message="Unexpected text was present",
)
message = "Website check passed"
if tls_message:
message = f"{message}; {tls_message}"
return WebsiteCheckResult(status="up", response_time_ms=response_time_ms, message=message)
async def check_tls_expiry(url: str, warning_days: int, timeout_seconds: float) -> TlsExpiryResult:
parsed_url = urlparse(url)
if parsed_url.scheme != "https":
return TlsExpiryResult(status="up", response_time_ms=0, message="TLS expiry check skipped for non-HTTPS target")
if not parsed_url.hostname:
return TlsExpiryResult(status="down", response_time_ms=0, message="TLS check could not determine the hostname")
started = perf_counter()
try:
expires_at = await _get_certificate_expiry(parsed_url.hostname, parsed_url.port or 443, timeout_seconds)
except (OSError, ssl.SSLError, ValueError) as exc:
return TlsExpiryResult(status="down", response_time_ms=int((perf_counter() - started) * 1000), message=f"TLS certificate check failed: {exc}")
response_time_ms = int((perf_counter() - started) * 1000)
now = datetime.now(UTC)
days_remaining = (expires_at - now).total_seconds() / 86400
days_remaining_text = str(max(0, int(days_remaining)))
if days_remaining < 0:
return TlsExpiryResult(
status="down",
response_time_ms=response_time_ms,
message=f"TLS certificate expired on {expires_at.date().isoformat()}",
)
if days_remaining <= warning_days:
return TlsExpiryResult(
status="warning",
response_time_ms=response_time_ms,
message=f"TLS certificate expires in {days_remaining_text} days on {expires_at.date().isoformat()}",
)
return TlsExpiryResult(
status="up",
response_time_ms=response_time_ms,
message=f"TLS certificate valid for {days_remaining_text} days until {expires_at.date().isoformat()}",
)
async def _get_certificate_expiry(hostname: str, port: int, timeout_seconds: float) -> datetime:
return await asyncio.to_thread(_get_certificate_expiry_sync, hostname, port, timeout_seconds)
def _get_certificate_expiry_sync(hostname: str, port: int, timeout_seconds: float) -> datetime:
context = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
context.check_hostname = False
context.verify_mode = ssl.CERT_NONE
with socket.create_connection((hostname, port), timeout=timeout_seconds) as sock:
with context.wrap_socket(sock, server_hostname=hostname) as tls_sock:
certificate_bytes = tls_sock.getpeercert(binary_form=True)
if not certificate_bytes:
raise ValueError("certificate did not include an expiry date")
certificate = x509.load_der_x509_certificate(certificate_bytes)
return certificate.not_valid_after_utc