feat(observability): Langfuse 전송 — 턴 마무리(사용자 trace)·게이트웨이(FabriX generation) 두 훅, SDK 없이 HTTP. deploy/langfuse 에 compose+env+반입 절차

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

5_django_backend/tests/test_langfuse.py

@@ -0,0 +1,87 @@
+"""Langfuse 전송 — 이벤트 모양·인증·게이트웨이/턴 마무리 훅. 서버는 MockTransport."""
+
+import asyncio
+import base64
+import json
+
+import httpx
+import pytest
+from django.test import override_settings
+
+from apps.gateway import langfuse
+
+LF = {"host": "http://lf.test", "public_key": "pk-lf-a", "secret_key": "sk-lf-b"}
+
+
+@pytest.fixture
+def lf_server(monkeypatch):
+    got: list[dict] = []
+
+    def handler(req: httpx.Request) -> httpx.Response:
+        got.append({"url": str(req.url), "auth": req.headers.get("authorization"), "body": json.loads(req.content)})
+        return httpx.Response(207, json={"successes": [], "errors": []})
+
+    monkeypatch.setattr(langfuse, "TRANSPORT", httpx.MockTransport(handler))
+    return got
+
+
+@override_settings(LANGFUSE=LF)
+async def test_send_batch_shape_and_basic_auth(lf_server):
+    ok = await langfuse.send([
+        langfuse.trace("t1", "chat", userId="u@x.com", sessionId="s1"),
+        langfuse.generation("t1", "gen", model="581", usage=langfuse.usage_of(10, 5)),
+    ])
+    assert ok and len(lf_server) == 1
+    req = lf_server[0]
+    assert req["url"] == "http://lf.test/api/public/ingestion"
+    assert req["auth"] == "Basic " + base64.b64encode(b"pk-lf-a:sk-lf-b").decode()
+    batch = req["body"]["batch"]
+    assert [e["type"] for e in batch] == ["trace-create", "generation-create"]
+    assert batch[0]["body"] == {"id": "t1", "name": "chat", "userId": "u@x.com", "sessionId": "s1"}
+    assert batch[1]["body"]["traceId"] == "t1" and batch[1]["body"]["usage"] == {"input": 10, "output": 5, "total": 15}
+    assert batch[0]["id"] != batch[1]["id"] and batch[0]["timestamp"].endswith("Z")
+
+
+@override_settings(LANGFUSE={"host": "", "public_key": "", "secret_key": ""})
+async def test_disabled_is_noop(lf_server):
+    assert not langfuse.enabled()
+    assert await langfuse.send([langfuse.trace("t", "x")]) is False
+    langfuse.send_later([langfuse.trace("t", "x")])
+    assert lf_server == []
+
+
+def test_collect_parses_sse_text_and_usage():
+    from apps.gateway.views import _Collect
+
+    c = _Collect()
+    c.feed(b'data: {"choices":[{"delta":{"content":"SEL"}}]}\n\ndata: {"choices":[{"delta":{"co')
+    c.feed(b'ntent":"ECT"}}],"usage":{"prompt_tokens":7,"completion_tokens":2}}\n\ndata: [DONE]\n\n')
+    assert "".join(c.text) == "SELECT" and c.usage == {"prompt_tokens": 7, "completion_tokens": 2}
+
+
+@pytest.mark.django_db(transaction=True)
+async def test_finalize_sends_user_trace(lf_server, django_user_model, monkeypatch):
+    from apps.chat import stream as stream_mod
+    from apps.chat.models import ChatSession
+    from apps.chat.stream import TurnState, _finalize
+    from common.opencode_service import opencode_service
+
+    async def _msgs(_sid):
+        return [{"info": {"role": "assistant", "tokens": {"input": 3, "output": 4, "reasoning": 1}, "time": {"created": 1000, "completed": 1500}}, "parts": [{"type": "text", "text": "답"}]}]
+
+    async def _sess(_sid):
+        return {"title": "MARA 조회"}
+
+    monkeypatch.setattr(opencode_service, "list_messages_a", _msgs)
+    monkeypatch.setattr(opencode_service, "get_session_a", _sess)
+    user = await django_user_model.objects.acreate(username="u@x.com", email="u@x.com")
+    session = await ChatSession.objects.acreate(id="ses_1", user=user, is_generating=True)
+    with override_settings(LANGFUSE=LF):
+        await _finalize(session, TurnState("ses_1", "질문"), 1.0)
+        await asyncio.gather(*list(langfuse._pending))
+    assert len(lf_server) == 1
+    batch = lf_server[0]["body"]["batch"]
+    t, g = batch[0]["body"], batch[1]["body"]
+    assert t["userId"] == "u@x.com" and t["sessionId"] == "ses_1" and t["input"] == "질문" and t["output"] == "답"
+    assert g["traceId"] == t["id"] and g["usage"] == {"input": 3, "output": 5, "total": 8} and g["level"] == "DEFAULT"
+    assert stream_mod is not None