Files
hermes-agent/hermes_cli/azure_detect.py

341 lines
14 KiB
Python

"""Azure Foundry endpoint auto-detection.
The detector never crashes on errors (every HTTP call is wrapped in a broad try/except). Callers get
a :class:`DetectionResult` with whatever information could be gathered, and fall back to manual
entry for the rest.
"""
from __future__ import annotations
import json
import logging
import re
from dataclasses import dataclass, field
from typing import Any, Callable, Optional
from urllib import request as urllib_request
from urllib.error import HTTPError, URLError
from urllib.parse import urlparse
from hermes_cli.urllib_security import open_credentialed_url
logger = logging.getLogger(__name__)
# Default Azure OpenAI ``api-version`` to probe with. The v1 GA endpoint
# accepts requests without ``api-version`` entirely, so this is only used
# as a fallback for pre-v1 resources that still require it.
_AZURE_OPENAI_PROBE_API_VERSIONS = (
"2025-04-01-preview",
"2024-10-21", # oldest GA that supports /models
)
# Default Azure Anthropic ``api-version``. Matches the value used by
# ``agent/anthropic_adapter.py`` when building the Anthropic client.
_AZURE_ANTHROPIC_API_VERSION = "2025-04-15"
@dataclass
class DetectionResult:
"""Everything auto-detection could gather from a base URL + API key."""
#: Detected API transport: ``"chat_completions"``,
#: ``"anthropic_messages"``, or ``None`` when detection failed.
api_mode: Optional[str] = None
#: Deployment / model IDs returned by ``/models`` (best effort).
#: Empty when the endpoint doesn't expose the list with an API key.
models: list[str] = field(default_factory=list)
#: Lowercased host from the base URL (used for display messages).
hostname: str = ""
#: Human-readable reason the detector chose ``api_mode``. Useful
#: for explaining auto-detection to the user in the wizard.
reason: str = ""
#: ``True`` when ``/models`` returned a valid OpenAI-shaped payload.
models_probe_ok: bool = False
#: ``True`` when the URL was determined to be an Anthropic-style
#: endpoint (from path suffix or live probe).
is_anthropic: bool = False
def _resolve_credential(api_key: Any,
token_provider: Optional[Callable[[], str]] = None,
) -> tuple[Optional[str], str]:
"""Coerce wizard inputs into a (token, mode) pair.
Returns ``(token_or_None, mode)`` where ``mode`` is: - ``"entra_id"`` when a callable token
provider was supplied — the returned token is a freshly minted bearer JWT, sent ONLY in
``Authorization: Bearer``.
"""
# Token-provider path (callable wins when both supplied).
for provider, label in ((token_provider, "token_provider"), (api_key, "api_key callable")):
if callable(provider) and not isinstance(provider, str):
try:
token = provider()
return (str(token) if token else None), "entra_id"
except Exception as exc:
logger.debug("azure_detect: %s failed: %s", label, exc)
return None, "entra_id"
# API-key path.
if isinstance(api_key, str) and api_key:
return api_key, "api_key"
return None, "api_key"
def _authed_request(url: str, api_key: Any, token_provider, *, method: str = "GET",
data: Optional[bytes] = None) -> urllib_request.Request:
"""Build a request carrying the right auth headers for the credential mode."""
token, mode = _resolve_credential(api_key, token_provider)
req = urllib_request.Request(url, method=method, data=data)
if token:
if mode != "entra_id":
# Legacy broad-compat behaviour: send both headers so we land on
# any Azure resource regardless of which it accepts.
req.add_header("api-key", token)
# Bearer-only in entra_id mode: do NOT also set api-key, which would
# log a JWT in a header slot intended for static keys.
req.add_header("Authorization", f"Bearer {token}")
req.add_header("User-Agent", "hermes-agent/azure-detect")
return req
def _http_get_json(url: str,
api_key: Any,
timeout: float = 6.0,
*,
token_provider: Optional[Callable[[], str]] = None,
) -> tuple[int, Optional[dict]]:
"""GET a URL with the appropriate auth headers. Return
``(status_code, parsed_json_or_None)``. Never raises."""
req = _authed_request(url, api_key, token_provider)
try:
with open_credentialed_url(req, timeout=timeout) as resp:
body = resp.read()
try:
return resp.status, json.loads(body.decode("utf-8", errors="replace"))
except Exception:
return resp.status, None
except HTTPError as exc:
return exc.code, None
except (URLError, TimeoutError, OSError) as exc:
logger.debug("azure_detect: GET %s failed: %s", url, exc)
return 0, None
except Exception as exc: # pragma: no cover — defensive
logger.debug("azure_detect: GET %s unexpected error: %s", url, exc)
return 0, None
def _strip_trailing_v1(url: str) -> str:
"""Strip trailing ``/v1`` or ``/v1/`` so we can construct sub-paths."""
return re.sub(r"/v1/?$", "", url.rstrip("/"))
def _looks_like_anthropic_path(url: str) -> bool:
"""Return True when the URL's path ends in ``/anthropic`` or contains a ``/anthropic/`` segment.
Used by Azure Foundry resources that route Claude traffic through a dedicated path.
"""
try:
parsed = urlparse(url)
path = (parsed.path or "").lower().rstrip("/")
return path.endswith("/anthropic") or "/anthropic/" in path + "/"
except Exception:
return False
def _extract_model_ids(payload: dict) -> list[str]:
"""Extract a list of model IDs from an OpenAI-shaped ``/models``
response. Returns ``[]`` on any shape mismatch."""
data = payload.get("data") if isinstance(payload, dict) else None
if not isinstance(data, list):
return []
ids: list[str] = []
for item in data:
if not isinstance(item, dict):
continue
# OpenAI shape: {"id": "gpt-5.4", "object": "model", ...}
mid = item.get("id") or item.get("model") or item.get("name")
if isinstance(mid, str) and mid:
ids.append(mid)
return ids
def _probe_openai_models(base_url: str,
api_key: Any,
*,
token_provider: Optional[Callable[[], str]] = None,
) -> tuple[bool, list[str]]:
"""Probe ``<base>/models`` for an OpenAI-shaped response."""
base_url = base_url.rstrip("/")
# Azure OpenAI v1: {resource}.openai.azure.com/openai/v1 — no
# api-version required for GA paths, so probe without first.
# Fallback: explicit api-version for pre-v1 resources
candidates = [f"{base_url}/models"] + [
f"{base_url}/models?api-version={v}" for v in _AZURE_OPENAI_PROBE_API_VERSIONS
]
for url in candidates:
status, body = _http_get_json(url, api_key, token_provider=token_provider)
if status == 200 and body is not None:
ids = _extract_model_ids(body)
if ids:
logger.info(
"azure_detect: /models probe OK at %s (%d models)",
url, len(ids),
)
return True, ids
# 200 + empty list still counts as "OpenAI shape, no models
# listed" — let the user proceed with manual entry.
if isinstance(body, dict) and "data" in body:
return True, []
return False, []
def _probe_anthropic_messages(base_url: str,
api_key: Any,
*,
token_provider: Optional[Callable[[], str]] = None,
) -> bool:
"""Send a zero-token request to ``<base>/v1/messages`` and check whether the endpoint at least
*recognises* the Anthropic Messages shape (any 4xx that mentions ``messages`` or ``model``, or a
400 ``invalid_request`` with an Anthropic error shape). Never completes a real chat.
"""
base = _strip_trailing_v1(base_url)
url = f"{base}/v1/messages?api-version={_AZURE_ANTHROPIC_API_VERSION}"
payload = json.dumps({
"model": "probe",
"max_tokens": 1,
"messages": [{"role": "user", "content": "ping"}],
}).encode("utf-8")
req = _authed_request(url, api_key, token_provider, method="POST", data=payload)
req.add_header("anthropic-version", "2023-06-01")
req.add_header("content-type", "application/json")
try:
with open_credentialed_url(req, timeout=6.0) as resp:
# Should never 200 — "probe" isn't a real deployment. But
# if it does, the endpoint definitely speaks Anthropic.
return resp.status < 500
except HTTPError as exc:
# 4xx with an Anthropic-shaped error body = Anthropic endpoint.
try:
body = exc.read().decode("utf-8", errors="replace")
lowered = body.lower()
if "anthropic" in lowered or '"type"' in lowered and '"error"' in lowered:
return True
# Pre-Azure-v1 Azure Foundry returns a plain 404 for
# Anthropic-style calls on non-Anthropic deployments. A
# 400 "model not found" IS Anthropic though.
if exc.code == 400 and ("messages" in lowered or "model" in lowered):
return True
return False
except Exception:
return False
except (URLError, TimeoutError, OSError):
return False
except Exception: # pragma: no cover
return False
def detect(base_url: str,
api_key: Any = "",
*,
token_provider: Optional[Callable[[], str]] = None,
) -> DetectionResult:
"""Inspect an Azure endpoint and describe its transport + models.
Call this from the wizard before asking the user to pick an API mode manually. The caller should
treat the returned :class:`DetectionResult` as *advisory* — if ``api_mode`` is None, fall back
to asking the user.
``api_key`` may be a string (legacy API-key auth — sends both ``api-key:`` and ``Authorization:
Bearer``) or a callable returning a bearer JWT (Entra ID auth — sends ONLY ``Authorization:
Bearer``). ``token_provider`` is an alternative explicit name for the callable form; if both are
supplied the callable wins.
"""
result = DetectionResult()
try:
parsed = urlparse(base_url)
result.hostname = (parsed.hostname or "").lower()
except Exception:
result.hostname = ""
# 1. Path sniff. Azure Foundry exposes Anthropic-style deployments
# under a dedicated ``/anthropic`` path.
if _looks_like_anthropic_path(base_url):
result.is_anthropic = True
result.api_mode = "anthropic_messages"
result.reason = "URL path ends in /anthropic → Anthropic Messages API"
return result
# 2. Try the OpenAI-style /models probe. If this works, the
# endpoint definitely speaks OpenAI wire.
ok, models = _probe_openai_models(base_url, api_key, token_provider=token_provider)
if ok:
result.models_probe_ok = True
result.models = models
result.api_mode = "chat_completions"
result.reason = (
f"GET /models returned {len(models)} model(s) — OpenAI-style endpoint"
if models
else "GET /models returned an OpenAI-shaped empty list — OpenAI-style endpoint"
)
return result
# 3. Fallback: probe the Anthropic Messages shape. Slower and more
# intrusive than /models, so only run it when the OpenAI probe
# failed.
if _probe_anthropic_messages(base_url, api_key, token_provider=token_provider):
result.is_anthropic = True
result.api_mode = "anthropic_messages"
result.reason = "Endpoint accepts Anthropic Messages shape"
return result
# Nothing matched. Caller falls back to manual selection.
result.reason = (
"Could not probe endpoint (private network, missing model list, or "
"non-standard path) — falling back to manual API-mode selection"
)
return result
def lookup_context_length(model: str,
base_url: str,
api_key: Any = "",
*,
token_provider: Optional[Callable[[], str]] = None,
) -> Optional[int]:
"""Thin wrapper around :func:`agent.model_metadata.get_model_context_length` that returns ``None``
when only the fallback default (128k) would fire, so the wizard can distinguish "we actually
know this" from "we guessed.
"""
model_id = str(model or "").strip()
if not model_id:
return None
try:
from agent.model_metadata import (
DEFAULT_FALLBACK_CONTEXT,
get_model_context_length,
)
except Exception:
return None
# Resolve the credential once. For Entra mode this calls the token
# provider; for legacy api_key this is a no-op string pass-through.
token, _mode = _resolve_credential(api_key, token_provider)
try:
n = get_model_context_length(model_id, base_url=base_url, api_key=token or "")
except Exception as exc:
logger.debug("azure_detect: context length lookup failed: %s", exc)
return None
if isinstance(n, int) and n > 0 and n != DEFAULT_FALLBACK_CONTEXT:
return n
return None
__all__ = ["DetectionResult", "detect", "lookup_context_length"]