From bfd79d751b51d5355c28bca10832423f576f350a Mon Sep 17 00:00:00 2001
From: liugq <silenceqi@hotmail.com>
Date: Sun, 22 May 2022 15:28:26 +0800
Subject: [PATCH] fixed no metric data when length of metric item equals 1

---
 plugin/api/alerting/rule.go | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/plugin/api/alerting/rule.go b/plugin/api/alerting/rule.go
index 479639a9..13dd2fa8 100644
--- a/plugin/api/alerting/rule.go
+++ b/plugin/api/alerting/rule.go
@@ -655,11 +655,19 @@ func getRuleMetricData( rule *alerting.Rule, filterParam *alerting.FilterParam)
 			continue
 		}
 		//filteredMetricData = append(filteredMetricData, md)
+
+		targetData := md.Data["result"]
+		if len(rule.Metrics.Items) == 1 {
+			for k, _ := range md.Data {
+				targetData = md.Data[k]
+				break
+			}
+		}
 		if sampleData == nil {
-			sampleData = md.Data["result"]
+			sampleData = targetData
 		}
 		metricItem.Lines = append(metricItem.Lines, &common.MetricLine{
-			Data:       md.Data["result"],
+			Data:  targetData,
 			BucketSize: filterParam.BucketSize,
 			Metric: common.MetricSummary{
 				Label:      strings.Join(md.GroupValues, "-"),