Fix: do not spam errors for relatively common conditions

docker-compose/tango-prometheus-exporter/code/tango-prometheus-client.py

@@ -176,7 +176,7 @@ class CustomCollector(object):
         attr_infos = {attr_info.name: attr_info for attr_info in dev.attribute_list_query()}
 
         if dev.state() not in [DevState.STANDBY, DevState.ON, DevState.ALARM, DevState.DISABLE]:
-            logger.error(f"Error processing device {device_name}: it is in state {dev.state()}")
+            logger.warning(f"Error processing device {device_name}: it is in state {dev.state()}")
 
             # at least log state & status
             attrs_to_scrape = ["State", "Status"]
@@ -195,7 +195,7 @@ class CustomCollector(object):
                 metrics.extend(self.metrics(dev, attr_infos[attr_name], attr_value))
             except DevFailed as e:
                 reason = e.args[0].desc.replace("\n", " ")
-                logger.error(f"Error processing device {device_name} attribute {attr_name}: {reason}")
+                logger.warning(f"Error processing device {device_name} attribute {attr_name}: {reason}")
             except Exception as e:
                 logger.exception(f"Error processing device {device_name} attribute {attr_name}")
 
@@ -220,7 +220,7 @@ class CustomCollector(object):
                     attribute_metrics.add_metric(*metric)
             except DevFailed as e:
                 reason = e.args[0].desc.replace("\n", " ")
-                logger.error(f"Error processing device {device_name}: {reason}")
+                logger.warning(f"Error processing device {device_name}: {reason}")
             except Exception as e:
                 logger.exception(f"Error processing device {device_name}")
             finally: