docker environment control improvement

APP_CORE/openvpn_gatherer_v3.py

@@ -142,14 +142,8 @@ class OpenVPNDataGatherer:
                 'agg_6h_retention_days': '180',  # 6 месяцев
                 'agg_1d_retention_days': '365'   # 12 месяцев
             },
-            'visualization': {
-                'refresh_interval': '5',
-                'max_display_rows': '50'
-            },
-            'certificates': {
-                'certificates_path': '/opt/ovpn/pki/issued',
-                'certificate_extensions': 'crt'
-            }
+            'visualization': {},
+            'certificates': {}
         }
 
         try:
@@ -214,6 +208,12 @@ class OpenVPNDataGatherer:
 
     def get_config_value(self, section, key, default=None):
         try:
+            # Priority: ENV > Config File > Fallback
+            # Format: OVPMON_SECTION_KEY (all uppercase, underscores for spaces/dashes)
+            env_key = f"OVPMON_{section.upper()}_{key.upper()}".replace('-', '_').replace(' ', '_')
+            env_val = os.getenv(env_key)
+            if env_val is not None:
+                return env_val
             return self.config.get(section, key, fallback=default)
         except:
             return default