From 2798097623ff848742912b501091b3469b693e3c Mon Sep 17 00:00:00 2001
From: GeoffreyCoulaud <geoffrey.coulaud@gmail.com>
Date: Mon, 12 Jun 2023 03:27:43 +0200
Subject: [PATCH] =?UTF-8?q?=F0=9F=8E=A8=20Improved=20logging=20code?=
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- Silenced unwanted library messages
- Logging to file with a max size of 8MB

When the file size is passed, a backup of the file is created,
and the file gets truncated.
There can only be one current file and one backup file.
---
 src/logging/setup.py | 62 +++++++++++++++++++++++++++++---------------
 src/main.py          |  7 +----
 2 files changed, 42 insertions(+), 27 deletions(-)

diff --git a/src/logging/setup.py b/src/logging/setup.py
index 83dbc9b..c8184ff 100644
--- a/src/logging/setup.py
+++ b/src/logging/setup.py
@@ -1,6 +1,6 @@
+import logging
 import logging.config as logging_dot_config
 import os
-from datetime import datetime
 
 from src import shared
 
@@ -8,51 +8,71 @@ from src import shared
 def setup_logging():
     """Intitate the app's logging"""
 
-    # Prepare log file
+    # Prepare the log file
     log_dir = shared.data_dir / "cartridges" / "logs"
     log_dir.mkdir(exist_ok=True)
-    log_file = log_dir / f'{datetime.now().isoformat(timespec="seconds")}.log'
+    log_file_path = log_dir / "cartridges.log"
+    log_file_max_size_bytes = 8 * 10**6  # 8 MB
 
     # Define log levels
-    profile_main_log_level = "DEBUG" if shared.PROFILE == "development" else "WARNING"
+    profile_app_log_level = "DEBUG" if shared.PROFILE == "development" else "INFO"
     profile_lib_log_level = "INFO" if shared.PROFILE == "development" else "WARNING"
-    main_log_level = os.environ.get("LOGLEVEL", profile_main_log_level).upper()
+    app_log_level = os.environ.get("LOGLEVEL", profile_app_log_level).upper()
     lib_log_level = os.environ.get("LIBLOGLEVEL", profile_lib_log_level).upper()
 
-    # Load config
     config = {
         "version": 1,
         "formatters": {
-            "console_formatter": {
-                "class": "src.logging.color_log_formatter.ColorLogFormatter",
-                "format": "%(name)s %(levelname)s - %(message)s",
-            },
             "file_formatter": {
                 "format": "%(asctime)s | %(name)s | %(levelname)s | %(message)s"
             },
+            "console_formatter": {
+                "format": "%(name)s %(levelname)s - %(message)s",
+                "class": "src.logging.color_log_formatter.ColorLogFormatter",
+            },
         },
         "handlers": {
-            "main_console_handler": {
+            "file_handler": {
+                "class": "logging.handlers.RotatingFileHandler",
+                "formatter": "file_formatter",
+                "level": "DEBUG",
+                "filename": log_file_path,
+                "maxBytes": log_file_max_size_bytes,
+                "backupCount": 1,
+            },
+            "app_console_handler": {
                 "class": "logging.StreamHandler",
                 "formatter": "console_formatter",
-                "level": main_log_level,
+                "level": app_log_level,
             },
             "lib_console_handler": {
                 "class": "logging.StreamHandler",
                 "formatter": "console_formatter",
                 "level": lib_log_level,
             },
-            "file_handler": {
-                "class": "logging.FileHandler",
-                "level": "DEBUG",
-                "filename": str(log_file),
-                "formatter": "file_formatter",
-            },
         },
         "loggers": {
-            "PIL": {"handlers": ["lib_console_handler", "file_handler"]},
-            "urllib3": {"handlers": ["lib_console_handler", "file_handler"]},
-            "root": {"handlers": ["main_console_handler", "file_handler"]},
+            "PIL": {
+                "handlers": ["lib_console_handler", "file_handler"],
+                "propagate": False,
+                "level": "NOTSET",
+            },
+            "urllib3": {
+                "handlers": ["lib_console_handler", "file_handler"],
+                "propagate": False,
+                "level": "NOTSET",
+            },
+        },
+        "root": {
+            "level": "NOTSET",
+            "handlers": ["app_console_handler", "file_handler"],
         },
     }
     logging_dot_config.dictConfig(config)
+
+    # Inform of the logging behaviour
+    logging.info("Logging profile: %s", shared.PROFILE)
+    logging.info("Console logging level for application: %s", app_log_level)
+    logging.info("Console logging level for libraries: %s", lib_log_level)
+    logging.info("Use env vars LOGLEVEL, LIBLOGLEVEL to override")
+    logging.info("All message levels are written to the log file")
diff --git a/src/main.py b/src/main.py
index f4f413f..8ac30dd 100644
--- a/src/main.py
+++ b/src/main.py
@@ -16,9 +16,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
 # SPDX-License-Identifier: GPL-3.0-or-later
-
 import json
-import logging
 import sys
 
 import gi
@@ -255,10 +253,7 @@ class CartridgesApplication(Adw.Application):
             scope.add_action(simple_action)
 
 
-def main(version):  # pylint: disable=unused-argument
-    # Initiate logger
-    logging.basicConfig(level="DEBUG")
+def main(_version):
     setup_logging()
-    # Start app
     app = CartridgesApplication()
     return app.run(sys.argv)