Now set up full Django logging for 404

settings.py

@@ -1,5 +1,7 @@
+import logging
 import sys
 from datetime import date
+from pathlib import Path
 from socket import gethostname
 
 """
@@ -76,6 +78,76 @@ USE_L10N = True
 
 FIX_PERMISSIONS = []
 
+
+### LOGGING set up here --------------------
+class RequireDevServerTrue(logging.Filter):
+    """Filter that only allows records through if DEVSERVER is True."""
+    def filter(self, record):
+        return DEVSERVER
+
+PRIMARY_LOG_DIR = Path("/var/log/troggle")
+FALLBACK_LOG_DIR = Path(__file__).parent / "BACKUP_LOGGING"
+log_filename = "troggle.log"
+    
+try:
+    PRIMARY_LOG_DIR.mkdir(parents=True, exist_ok=True)
+    final_log_path = PRIMARY_LOG_DIR / log_filename
+except (PermissionError, OSError):
+    FALLBACK_LOG_DIR.mkdir(parents=True, exist_ok=True)
+    final_log_path = FALLBACK_LOG_DIR / log_filename
+    print(f"!! Log permission denied at /var/log. Falling back to: {final_log_path}")
+ 
+LOGGING = {
+    "version": 1,
+    "disable_existing_loggers": False,
+    "formatters": {
+        "timestamped": {
+            "format": "{asctime} {message}",
+            # "format": "{levelname} {asctime} {module} {message}",
+            # "format": "{levelname} [{module}:{lineno}] {message}" # for bug reporting
+            "style": "{",
+            "datefmt": "%Y-%m-%d %H:%M:%S", # No milliseconds
+        },
+        "simple": {
+            "format": "{levelname} {asctime} [{module}:{lineno}] {message}",
+            "style": "{",
+            "datefmt": "%Y-%m-%d %H:%M:%S", # No milliseconds
+        },
+    },
+    "filters": {
+        "require_devserver_true": {
+            # Use the full import path to your class
+            # If this is in settings.py, you can use 'settings.RequireDevServerTrue'
+            "()": "settings.RequireDevServerTrue", 
+        },
+    },
+    "handlers": {
+        "file": {
+            "level": "WARNING",
+            "class": "logging.handlers.RotatingFileHandler",
+            "filename": final_log_path,
+            "maxBytes": 1024 * 1024 * 5,
+            "backupCount": 5,
+            "formatter": "timestamped",
+        },
+        "console": {
+            "level": "INFO",
+            "filters": ["require_devserver_true"], # Applied here!
+            "class": "logging.StreamHandler",
+            "formatter": "simple",
+        },
+    },
+    "loggers": {
+        "troggle": {
+            "handlers": ["file", "console"],
+            "level": "INFO",
+            "propagate": True,
+        },
+    },
+}
+### LOGGING set up end  --------------------
+
+
 # top-level survex file basename (without .svx)
 # SURVEX_TOPNAME = "1623-and-1626-no-schoenberg-hs"
 SURVEX_TOPNAME = "troggle_import_root" # same, but without all the 'essentials' gubbins