logging: Set up logging in wsgi.py

Make flask use the gunicorn loggers when run under gunicorn,
otherwise, use our custom logging.

Putting the logging setup inside `create_app(…)` would cause each
worker to override the gunicorn loggers, meaning we were not receiving
the logs, especially for `debug(…)` calls.

2 files changed, 26 insertions, 14 deletions

diff --git a/qc_app/__init__.py b/qc_app/__init__.py
index c9756a1..88e65be 100644
--- a/qc_app/__init__.py
+++ b/qc_app/__init__.py
@@ -1,9 +1,7 @@
 """The Quality-Control Web Application entry point"""
 import os
-import sys
 import logging
 from pathlib import Path
-from logging import StreamHandler
 
 from flask import Flask
 
@@ -20,15 +18,6 @@ def override_settings_with_envvars(
     for setting in (key for key in app.config if key not in ignore):
         app.config[setting] = os.environ.get(setting) or app.config[setting]
 
-def setup_logging(app: Flask):
-    """Setup application logging"""
-    handler_stderr = StreamHandler(stream=sys.stderr)
-    app.logger.addHandler(handler_stderr)
-
-    rootlogger = logging.getLogger()
-    rootlogger.addHandler(handler_stderr)
-    rootlogger.setLevel(app.config["LOG_LEVEL"])
-
 def create_app():
     """The application factory"""
     app = Flask(__name__)
@@ -38,7 +27,6 @@ def create_app():
         app.config.from_envvar("QCAPP_CONF") # Override defaults with instance path
 
     override_settings_with_envvars(app, ignore=tuple())
-    setup_logging(app)
 
     if "QCAPP_SECRETS" in os.environ:
         app.config.from_envvar("QCAPP_SECRETS")
diff --git a/wsgi.py b/wsgi.py
index ff24d78..9fb63cb 100644
--- a/wsgi.py
+++ b/wsgi.py
@@ -1,9 +1,13 @@
 """Run the application"""
+import sys
+from logging import getLogger, StreamHandler
+
+from flask import Flask
 
 from qc_app import create_app
 from qc_app.check_connections import check_db, check_redis
 
-def check_and_build_app():
+def check_and_build_app() -> Flask:
     """Setup the application for running."""
     # Setup the app
     appl = create_app()
@@ -13,8 +17,28 @@ def check_and_build_app():
     check_redis(appl.config["REDIS_URL"])
     return appl
 
+def setup_logging(appl: Flask):
+    """Setup application logging"""
+    loglevel = appl.config["LOG_LEVEL"].upper()
+
+    # Maybe call `logging.dictConfig(…)` here instead of all this stuff below
+    handler_stderr = StreamHandler(stream=sys.stderr)
+    appl.logger.addHandler(handler_stderr)
+
+    rootlogger = getLogger()
+    rootlogger.addHandler(handler_stderr)
+    rootlogger.setLevel(loglevel)
+
+    appl.logger.setLevel(loglevel)
+
 app = check_and_build_app()
 
-if __name__ == "__main__":
+if __name__ != "__main__":# Running via gunicorn
+    gunicorn_logger = getLogger("gunicorn.error")
+    app.logger.handlers = gunicorn_logger.handlers
+    app.logger.setLevel(gunicorn_logger.level)#pylint: disable=[no-member]
+
+if __name__ == "__main__":# Running via flask
     # Run the app
+    setup_logging(app)
     app.run()