feat: add usename label

Signed-off-by: rezaxd <r324r11@gmail.com>

Author: rezaxd

collector/pg_process_idle.go

@@ -89,12 +89,13 @@ func (PGProcessIdleCollector) Update(ctx context.Context, instance *instance, ch
 
 	var state sql.NullString
 	var applicationName sql.NullString
+	var usename sql.NullString
 	var secondsSum sql.NullFloat64
 	var secondsCount sql.NullInt64
 	var seconds []float64
 	var secondsBucket []int64
 
-	err := row.Scan(&state, &applicationName, &secondsSum, &secondsCount, pq.Array(&seconds), pq.Array(&secondsBucket))
+	err := row.Scan(&state, &applicationName, &usename, &secondsSum, &secondsCount, pq.Array(&seconds), pq.Array(&secondsBucket))
 	if err != nil {
 		return err
 	}
@@ -117,6 +118,11 @@ func (PGProcessIdleCollector) Update(ctx context.Context, instance *instance, ch
 		applicationNameLabel = applicationName.String
 	}
 
+	usenameLabel := "unknown"
+	if usename.Valid {
+		usenameLabel = usename.String
+	}
+
 	var secondsCountMetric uint64
 	if secondsCount.Valid {
 		secondsCountMetric = uint64(secondsCount.Int64)
@@ -128,7 +134,7 @@ func (PGProcessIdleCollector) Update(ctx context.Context, instance *instance, ch
 	ch <- prometheus.MustNewConstHistogram(
 		pgProcessIdleSeconds,
 		secondsCountMetric, secondsSumMetric, buckets,
-		stateLabel, applicationNameLabel,
+		stateLabel, applicationNameLabel, usenameLabel,
 	)
 	return nil
 }