Files
hermes-agent/gateway/platforms/telegram_network.py
Teknium d7c41f3cef fix(telegram): honor proxy env vars in fallback transport (salvage #3411) (#3591)
* fix: keep gateway running through telegram proxy failures

- continue gateway startup in degraded mode when Telegram cannot connect yet
- ensure Telegram fallback transport also honors proxy env vars
- support reconnect retries without taking down the whole gateway

* test(telegram): cover proxy env handling in fallback transport

---------

Co-authored-by: kufufu9 <pi@local>
2026-03-28 14:23:27 -07:00

246 lines
8.7 KiB
Python

"""Telegram-specific network helpers.
Provides a hostname-preserving fallback transport for networks where
api.telegram.org resolves to an endpoint that is unreachable from the current
host. The transport keeps the logical request host and TLS SNI as
api.telegram.org while retrying the TCP connection against one or more fallback
IPv4 addresses.
"""
from __future__ import annotations
import asyncio
import ipaddress
import logging
import os
import socket
from typing import Iterable, Optional
import httpx
logger = logging.getLogger(__name__)
_TELEGRAM_API_HOST = "api.telegram.org"
# DNS-over-HTTPS providers used to discover Telegram API IPs that may differ
# from the (potentially unreachable) IP returned by the local system resolver.
_DOH_TIMEOUT = 4.0 # seconds — bounded so connect() isn't noticeably delayed
_DOH_PROVIDERS: list[dict] = [
{
"url": "https://dns.google/resolve",
"params": {"name": _TELEGRAM_API_HOST, "type": "A"},
"headers": {},
},
{
"url": "https://cloudflare-dns.com/dns-query",
"params": {"name": _TELEGRAM_API_HOST, "type": "A"},
"headers": {"Accept": "application/dns-json"},
},
]
# Last-resort IPs when DoH is also blocked. These are stable Telegram Bot API
# endpoints in the 149.154.160.0/20 block (same seed used by OpenClaw).
_SEED_FALLBACK_IPS: list[str] = ["149.154.167.220"]
def _resolve_proxy_url() -> str | None:
for key in ("HTTPS_PROXY", "HTTP_PROXY", "ALL_PROXY", "https_proxy", "http_proxy", "all_proxy"):
value = (os.environ.get(key) or "").strip()
if value:
return value
return None
class TelegramFallbackTransport(httpx.AsyncBaseTransport):
"""Retry Telegram Bot API requests via fallback IPs while preserving TLS/SNI.
Requests continue to target https://api.telegram.org/... logically, but on
connect failures the underlying TCP connection is retried against a known
reachable IP. This is effectively the programmatic equivalent of
``curl --resolve api.telegram.org:443:<ip>``.
"""
def __init__(self, fallback_ips: Iterable[str], **transport_kwargs):
self._fallback_ips = [ip for ip in dict.fromkeys(_normalize_fallback_ips(fallback_ips))]
proxy_url = _resolve_proxy_url()
if proxy_url and "proxy" not in transport_kwargs:
transport_kwargs["proxy"] = proxy_url
self._primary = httpx.AsyncHTTPTransport(**transport_kwargs)
self._fallbacks = {
ip: httpx.AsyncHTTPTransport(**transport_kwargs) for ip in self._fallback_ips
}
self._sticky_ip: Optional[str] = None
self._sticky_lock = asyncio.Lock()
async def handle_async_request(self, request: httpx.Request) -> httpx.Response:
if request.url.host != _TELEGRAM_API_HOST or not self._fallback_ips:
return await self._primary.handle_async_request(request)
sticky_ip = self._sticky_ip
attempt_order: list[Optional[str]] = [sticky_ip] if sticky_ip else [None]
for ip in self._fallback_ips:
if ip != sticky_ip:
attempt_order.append(ip)
last_error: Exception | None = None
for ip in attempt_order:
candidate = request if ip is None else _rewrite_request_for_ip(request, ip)
transport = self._primary if ip is None else self._fallbacks[ip]
try:
response = await transport.handle_async_request(candidate)
if ip is not None and self._sticky_ip != ip:
async with self._sticky_lock:
if self._sticky_ip != ip:
self._sticky_ip = ip
logger.warning(
"[Telegram] Primary api.telegram.org path unreachable; using sticky fallback IP %s",
ip,
)
return response
except Exception as exc:
last_error = exc
if not _is_retryable_connect_error(exc):
raise
if ip is None:
logger.warning(
"[Telegram] Primary api.telegram.org connection failed (%s); trying fallback IPs %s",
exc,
", ".join(self._fallback_ips),
)
continue
logger.warning("[Telegram] Fallback IP %s failed: %s", ip, exc)
continue
assert last_error is not None
raise last_error
async def aclose(self) -> None:
await self._primary.aclose()
for transport in self._fallbacks.values():
await transport.aclose()
def _normalize_fallback_ips(values: Iterable[str]) -> list[str]:
normalized: list[str] = []
for value in values:
raw = str(value).strip()
if not raw:
continue
try:
addr = ipaddress.ip_address(raw)
except ValueError:
logger.warning("Ignoring invalid Telegram fallback IP: %r", raw)
continue
if addr.version != 4:
logger.warning("Ignoring non-IPv4 Telegram fallback IP: %s", raw)
continue
normalized.append(str(addr))
return normalized
def parse_fallback_ip_env(value: str | None) -> list[str]:
if not value:
return []
parts = [part.strip() for part in value.split(",")]
return _normalize_fallback_ips(parts)
def _resolve_system_dns() -> set[str]:
"""Return the IPv4 addresses that the OS resolver gives for api.telegram.org."""
try:
results = socket.getaddrinfo(_TELEGRAM_API_HOST, 443, socket.AF_INET)
return {addr[4][0] for addr in results}
except Exception:
return set()
async def _query_doh_provider(
client: httpx.AsyncClient, provider: dict
) -> list[str]:
"""Query one DoH provider and return A-record IPs."""
try:
resp = await client.get(
provider["url"], params=provider["params"], headers=provider["headers"]
)
resp.raise_for_status()
data = resp.json()
ips: list[str] = []
for answer in data.get("Answer", []):
if answer.get("type") != 1: # A record
continue
raw = answer.get("data", "").strip()
try:
ipaddress.ip_address(raw)
ips.append(raw)
except ValueError:
continue
return ips
except Exception as exc:
logger.debug("DoH query to %s failed: %s", provider["url"], exc)
return []
async def discover_fallback_ips() -> list[str]:
"""Auto-discover Telegram API IPs via DNS-over-HTTPS.
Resolves api.telegram.org through Google and Cloudflare DoH, collects all
unique IPs, and excludes the system-DNS-resolved IP (which is presumably
unreachable on this network). Falls back to a hardcoded seed list when DoH
is also unavailable.
"""
async with httpx.AsyncClient(timeout=httpx.Timeout(_DOH_TIMEOUT)) as client:
doh_tasks = [_query_doh_provider(client, p) for p in _DOH_PROVIDERS]
system_dns_task = asyncio.to_thread(_resolve_system_dns)
results = await asyncio.gather(system_dns_task, *doh_tasks, return_exceptions=True)
# results[0] = system DNS IPs (set), results[1:] = DoH IP lists
system_ips: set[str] = results[0] if isinstance(results[0], set) else set()
doh_ips: list[str] = []
for r in results[1:]:
if isinstance(r, list):
doh_ips.extend(r)
# Deduplicate preserving order, exclude system-DNS IPs
seen: set[str] = set()
candidates: list[str] = []
for ip in doh_ips:
if ip not in seen and ip not in system_ips:
seen.add(ip)
candidates.append(ip)
# Validate through existing normalization
validated = _normalize_fallback_ips(candidates)
if validated:
logger.debug("Discovered Telegram fallback IPs via DoH: %s", ", ".join(validated))
return validated
logger.info(
"DoH discovery yielded no new IPs (system DNS: %s); using seed fallback IPs %s",
", ".join(system_ips) or "unknown",
", ".join(_SEED_FALLBACK_IPS),
)
return list(_SEED_FALLBACK_IPS)
def _rewrite_request_for_ip(request: httpx.Request, ip: str) -> httpx.Request:
original_host = request.url.host or _TELEGRAM_API_HOST
url = request.url.copy_with(host=ip)
headers = request.headers.copy()
headers["host"] = original_host
extensions = dict(request.extensions)
extensions["sni_hostname"] = original_host
return httpx.Request(
method=request.method,
url=url,
headers=headers,
stream=request.stream,
extensions=extensions,
)
def _is_retryable_connect_error(exc: Exception) -> bool:
return isinstance(exc, (httpx.ConnectTimeout, httpx.ConnectError))