✨ Enhance logging configuration by introducing file output options and rotation settings in config.dev.toml. Update logger implementation to support multiple output streams, including file logging with rotation using lumberjack. Improve error handling and logging across various components, ensuring consistent logging practices. Update .gitignore to include log files and compressed logs. Add new Go module dependency for lumberjack.

internal/infra/nats/consumer.go

@@ -713,6 +713,12 @@ func (c *Consumer) routeToDLQ(ctx context.Context, msg *nats.Msg, cause error) e
 
 	data, err := json.Marshal(payload)
 	if err != nil {
+		c.logger.Error("failed to marshal DLQ payload",
+			zap.String("stream", c.streamName),
+			zap.String("consumer", c.consumerName),
+			zap.String("dlq_subject", c.dlqSubject),
+			zap.Error(err),
+		)
 		return fmt.Errorf("marshal dlq payload: %w", err)
 	}
 
@@ -722,9 +728,23 @@ func (c *Consumer) routeToDLQ(ctx context.Context, msg *nats.Msg, cause error) e
 		// unavailable. Surface this explicitly to make operational diagnosis
 		// easier.
 		if errors.Is(err, nats.ErrNoResponders) {
+			c.logger.Error("transient DLQ publish error (no responders)",
+				zap.String("stream", c.streamName),
+				zap.String("consumer", c.consumerName),
+				zap.String("dlq_subject", c.dlqSubject),
+				zap.Int("payload_size", len(data)),
+				zap.Error(err),
+			)
 			c.telemetry.RecordDLQPublishFailure(ctx, c.streamName, c.consumerName)
 			return fmt.Errorf("publish to dlq subject %s: no JetStream stream found for subject or JetStream unavailable: %w", c.dlqSubject, err)
 		}
+		c.logger.Error("failed to publish to DLQ",
+			zap.String("stream", c.streamName),
+			zap.String("consumer", c.consumerName),
+			zap.String("dlq_subject", c.dlqSubject),
+			zap.Int("payload_size", len(data)),
+			zap.Error(err),
+		)
 		c.telemetry.RecordDLQPublishFailure(ctx, c.streamName, c.consumerName)
 		return fmt.Errorf("publish to dlq subject %s: %w", c.dlqSubject, err)
 	}