Backend: Python-Logging statt print, Diagnose in allen Fallbacks

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

backend/agents.py

@@ -5,15 +5,19 @@ jeweilige Provider fehl — der andere läuft unverändert weiter.
 """
 
 import asyncio
+import logging
 import os
 import re
 import shutil
 import tempfile
+import time
 import urllib.request
 from pathlib import Path
 
 from config import PROVIDERS, DEFAULT_PROVIDER
 
+log = logging.getLogger("creator.agents")
+
 _active_processes: dict[str, asyncio.subprocess.Process] = {}
 
 # Capability → Claude --allowedTools
@@ -54,7 +58,11 @@ def provider_available(provider: str) -> bool:
 def kill_process(agent_key_prefix: str) -> None:
     """Killt alle aktiven Prozesse, deren Key mit dem Prefix beginnt (deckt -plan/-w1… ab)."""
     for key, process in list(_active_processes.items()):
-        if key.startswith(agent_key_prefix) and process.returncode is None:
+        if process.returncode is not None:  # tote Einträge beim Iterieren aufräumen
+            _active_processes.pop(key, None)
+            continue
+        if key.startswith(agent_key_prefix):
+            log.debug("kill agent %s", key)
             process.kill()
 
 
@@ -76,6 +84,7 @@ async def run_agent(
 
 
 async def _communicate(agent_key: str, cmd: list[str], stdin_data: bytes | None, timeout: int) -> tuple[int, str, str]:
+    start = time.monotonic()
     process = await asyncio.create_subprocess_exec(
         *cmd,
         stdin=asyncio.subprocess.PIPE if stdin_data is not None else asyncio.subprocess.DEVNULL,
@@ -95,10 +104,18 @@ async def _communicate(agent_key: str, cmd: list[str], stdin_data: bytes | None,
                 await asyncio.wait_for(process.wait(), timeout=5)
             except asyncio.TimeoutError:
                 pass
+            log.info("agent %s: Timeout nach %ds", agent_key, timeout)
             raise
+        log.info(
+            "agent %s: exit %s nach %.1fs (%d Bytes stdout)",
+            agent_key, process.returncode, time.monotonic() - start, len(stdout),
+        )
         return process.returncode, stdout.decode("utf-8", errors="replace"), stderr.decode("utf-8", errors="replace")
     finally:
-        _active_processes.pop(agent_key, None)
+        # Pop nur bei Identität: ein Slot-Restart unter demselben Key darf den
+        # NEUEN Prozess nicht aus dem Tracking werfen.
+        if _active_processes.get(agent_key) is process:
+            del _active_processes[agent_key]
 
 
 async def _run_claude_cli(agent_key: str, prompt: str, timeout: int, role: str, capabilities: str) -> tuple[int, str, str]:

backend/generator.py

@@ -1,5 +1,6 @@
 import asyncio
 import json
+import logging
 import math
 import shutil
 import subprocess
@@ -45,8 +46,11 @@ def _extra(instructions: str) -> str:
     return f"\n\nZUSÄTZLICHE ANWEISUNGEN VOM NUTZER:\n{instructions}\n" if instructions else ""
 
 
+log = logging.getLogger("creator.generator")
+
+
 def _log(topic: str, msg: str) -> None:
-    print(f"[generator] {topic}: {msg}", flush=True)
+    log.info("[%s] %s", topic, msg)
 
 
 def _claude_error(label: str, returncode: int, stdout: str, stderr: str) -> str:
@@ -112,7 +116,8 @@ def _json_datei(path: Path):
         text = path.read_text(encoding="utf-8").strip()
         text = re.sub(r"^```(?:json)?\s*|\s*```$", "", text)
         return json.loads(text)
-    except Exception:
+    except Exception as e:
+        log.debug("JSON-Datei ungültig: %s (%s)", path, e)
         return None
 
 
@@ -580,6 +585,7 @@ async def generate_bausteine(topic: str, instructions: str = "", provider: str =
                 encoding="utf-8",
             )
     except Exception as e:
+        log.exception("[%s] Bausteine-Generierung fehlgeschlagen", topic)
         _bausteine_errors[topic] = str(e)[:2000]
     finally:
         # Kein Datei-Cleanup: Zwischendateien bleiben für Resume bzw. Nachvollziehbarkeit.
@@ -1317,6 +1323,7 @@ async def generate_guide(guide_id: str, topic: str, format_name: str, instructio
         except FileNotFoundError:
             await _fail(guide_id, "Bausteine fehlen")
         except Exception as e:
+            log.exception("[%s] Guide-Generierung fehlgeschlagen (%s)", topic, guide_id)
             await _fail(guide_id, str(e)[:2000])
         finally:
             _cancelled.discard(guide_id)
@@ -1349,6 +1356,7 @@ async def chat_with_guide(topic: str, format_name: str, section: str, outline: s
         reply = stdout.strip()
         return reply or "Entschuldigung, ich habe keine Antwort erhalten."
     except Exception:
+        log.warning("[%s] Guide-Chat fehlgeschlagen", topic, exc_info=True)
         return "Entschuldigung, das hat nicht geklappt. Bitte versuche es erneut."
 
 
@@ -1432,6 +1440,7 @@ async def generate_element(topic: str, hint: str, provider: str = DEFAULT_PROVID
             return fallback
         return _element_fields(_parse_json_text(stdout)) or fallback
     except Exception:
+        log.warning("[%s] Element-Erstellung fehlgeschlagen", topic, exc_info=True)
         return fallback
 
 
@@ -1488,6 +1497,7 @@ async def check_element(element: dict, provider: str = DEFAULT_PROVIDER) -> list
             return None
         return _parse_suggestions(stdout)
     except Exception:
+        log.warning("[%s] Element-Prüfung fehlgeschlagen", element.get("topic", "?"), exc_info=True)
         return None
 
 
@@ -1545,6 +1555,7 @@ async def chat_with_element(element: dict, messages: list[dict], provider: str =
         reply = str(data.get("reply", "")).strip() or ("Vorschläge erstellt." if changes else fehler)
         return reply, changes
     except Exception:
+        log.warning("[%s] Element-Chat fehlgeschlagen", element.get("topic", "?"), exc_info=True)
         return fehler, []
 
 
@@ -1562,6 +1573,7 @@ async def style_element(element: dict, provider: str = DEFAULT_PROVIDER) -> list
             return None
         return [v for c in data.get("changes", []) if (v := _validate_change(c, element))]
     except Exception:
+        log.warning("[%s] Stil-Prüfung fehlgeschlagen", element.get("topic", "?"), exc_info=True)
         return None
 
 
@@ -1584,4 +1596,5 @@ async def refine_suggestion(element: dict, suggestion: dict, instruction: str, p
             return None
         return _validate_change(data.get("change"), element)
     except Exception:
+        log.warning("[%s] Vorschlags-Überarbeitung fehlgeschlagen", element.get("topic", "?"), exc_info=True)
         return None

backend/logsetup.py

@@ -0,0 +1,11 @@
+"""Zentrales Logging-Setup — einmal in main.py aufrufen, bevor die App entsteht."""
+
+import logging
+import os
+
+
+def setup_logging() -> None:
+    logging.basicConfig(
+        level=os.environ.get("LOG_LEVEL", "INFO").upper(),
+        format="%(asctime)s %(levelname)s %(name)s %(message)s",
+    )

backend/main.py

@@ -3,6 +3,10 @@ from contextlib import asynccontextmanager
 from fastapi import FastAPI
 from fastapi.staticfiles import StaticFiles
 
+from logsetup import setup_logging
+
+setup_logging()
+
 from config import FRONTEND_DIST, STORAGE_DIR
 from database import init_db, close_db
 from routes import router