Getting there

src/polymaker/logging.py

@@ -0,0 +1,66 @@
+"""structlog configuration: human console in dev, JSON to file in prod."""
+
+from __future__ import annotations
+
+import logging
+import sys
+from pathlib import Path
+from typing import Any
+
+import structlog
+
+
+def configure(
+    *,
+    level: str = "INFO",
+    json_file: Path | None = None,
+    console: bool = True,
+) -> None:
+    """Set up structlog + stdlib logging once at process start."""
+    shared: list[Any] = [
+        structlog.contextvars.merge_contextvars,
+        structlog.processors.add_log_level,
+        structlog.processors.TimeStamper(fmt="iso", utc=True),
+        structlog.processors.StackInfoRenderer(),
+        structlog.processors.format_exc_info,
+    ]
+
+    structlog.configure(
+        processors=[*shared, structlog.stdlib.ProcessorFormatter.wrap_for_formatter],
+        logger_factory=structlog.stdlib.LoggerFactory(),
+        wrapper_class=structlog.stdlib.BoundLogger,
+        cache_logger_on_first_use=True,
+    )
+
+    root = logging.getLogger()
+    root.handlers.clear()
+    root.setLevel(level)
+
+    if console:
+        ch = logging.StreamHandler(sys.stderr)
+        ch.setFormatter(
+            structlog.stdlib.ProcessorFormatter(
+                processors=[
+                    structlog.stdlib.ProcessorFormatter.remove_processors_meta,
+                    structlog.dev.ConsoleRenderer(colors=sys.stderr.isatty()),
+                ]
+            )
+        )
+        root.addHandler(ch)
+
+    if json_file is not None:
+        json_file.parent.mkdir(parents=True, exist_ok=True)
+        fh = logging.FileHandler(json_file)
+        fh.setFormatter(
+            structlog.stdlib.ProcessorFormatter(
+                processors=[
+                    structlog.stdlib.ProcessorFormatter.remove_processors_meta,
+                    structlog.processors.JSONRenderer(),
+                ]
+            )
+        )
+        root.addHandler(fh)
+
+
+def get_logger(name: str) -> structlog.stdlib.BoundLogger:
+    return structlog.get_logger(name)  # type: ignore[no-any-return]