add structured logging

pyproject.toml

@@ -9,8 +9,15 @@ description = "Temporary placeholder for fnb web site"
 readme = "README.md"
 requires-python = ">=3.11" # Self type added
 license = "AGPL-3.0-only"
-dependencies = ["flask", "gunicorn"]
+dependencies = [
+    "flask",
+    "gunicorn",
+    "structlog",
+]
 dynamic = ["version"]
 
 [project.scripts]
 # Put scripts here
+
+[tool.yapf]
+based_on_style = "facebook"

roc_fnb/util/__init__.py

@@ -0,0 +1 @@
+from roc_fnb.util.logging import log

roc_fnb/util/logging.py

@@ -0,0 +1,30 @@
+import logging
+from os import environ
+
+from structlog.processors import JSONRenderer, TimeStamper
+from structlog.dev import ConsoleRenderer
+import structlog
+
+if not structlog.is_configured():
+    if (env := environ.get('ENV_MODE')) and env == 'production':
+        timestamper = TimeStamper(fmt="%Y-%m-%d %H:%M:%S", utc=True)
+        renderer: JSONRenderer | ConsoleRenderer = JSONRenderer()
+    else:
+        timestamper = TimeStamper(fmt="%Y-%m-%d %H:%M:%S", utc=False)
+        renderer = ConsoleRenderer()
+    structlog.configure(
+        processors=[
+            structlog.contextvars.merge_contextvars,
+            structlog.processors.add_log_level,
+            structlog.processors.StackInfoRenderer(),
+            structlog.dev.set_exc_info,
+            timestamper,
+            renderer,
+        ],
+        wrapper_class=structlog.make_filtering_bound_logger(logging.NOTSET),
+        context_class=dict,
+        logger_factory=structlog.PrintLoggerFactory(),
+        cache_logger_on_first_use=False
+    )
+
+log = structlog.get_logger()