Setup module for logging

During development, we need logging sometimes to help with troubleshooting
problems. This commit provides a module to help set up the logging in a
separate module from the app module.

2 files changed, 25 insertions, 0 deletions

diff --git a/gn3/app.py b/gn3/app.py
index 0c2f9f9..b4b4b43 100644
--- a/gn3/app.py
+++ b/gn3/app.py
@@ -7,6 +7,7 @@ from typing import Union
 from flask import Flask
 from flask_cors import CORS # type: ignore
 
+from gn3.loggers import setup_app_handlers
 from gn3.api.gemma import gemma
 from gn3.api.rqtl import rqtl
 from gn3.api.general import general
@@ -42,6 +43,9 @@ def create_app(config: Union[Dict, str, None] = None) -> Flask:
         elif config.endswith(".py"):
             app.config.from_pyfile(config)
 
+    # DO NOT log anything before this point
+    setup_app_handlers(app)
+
     CORS(
         app,
         origins=app.config["CORS_ORIGINS"],
diff --git a/gn3/loggers.py b/gn3/loggers.py
new file mode 100644
index 0000000..a74ae7e
--- /dev/null
+++ b/gn3/loggers.py
@@ -0,0 +1,21 @@
+"""Setup loggers"""
+import sys
+import logging
+from logging import StreamHandler
+
+# ========== Setup formatters ==========
+# ========== END: Setup formatters ==========
+
+def loglevel(app):
+    """'Compute' the LOGLEVEL from the application."""
+    return logging.DEBUG if app.config.get("DEBUG", False) else logging.WARNING
+
+def setup_app_handlers(app):
+    """Setup the logging handlers for the application `app`."""
+    # ========== Setup handlers ==========
+    stderr_handler = StreamHandler(stream=sys.stderr)
+    stderr_handler.setLevel(loglevel(app))
+    app.logger.addHandler(stderr_handler)
+    # ========== END: Setup handlers ==========
+    root_logger = logging.getLogger()
+    root_logger.addHandler(stderr_handler)