Fix: #14706 Incorrect index pattern padding in alerting queries

When weekly index pattern is used, indices names contain single digit week number for week 1-9
This fix makes sure indice names always contain 2 digit week number for weekly pattern

pkg/tsdb/elasticsearch/client/index_pattern.go

@@ -279,7 +279,7 @@ func formatDate(t time.Time, pattern string) string {
 		isoYearShort := fmt.Sprintf("%d", isoYear)[2:4]
 		formatted = strings.Replace(formatted, "<stdIsoYear>", fmt.Sprintf("%d", isoYear), -1)
 		formatted = strings.Replace(formatted, "<stdIsoYearShort>", isoYearShort, -1)
-		formatted = strings.Replace(formatted, "<stdWeekOfYear>", fmt.Sprintf("%d", isoWeek), -1)
+		formatted = strings.Replace(formatted, "<stdWeekOfYear>", fmt.Sprintf("%02d", isoWeek), -1)
 
 		formatted = strings.Replace(formatted, "<stdUnix>", fmt.Sprintf("%d", t.Unix()), -1)
 

pkg/tsdb/elasticsearch/client/index_pattern_test.go

@@ -76,6 +76,15 @@ func TestIndexPattern(t *testing.T) {
 			So(indices, ShouldHaveLength, 1)
 			So(indices[0], ShouldEqual, "2018-data")
 		})
+
+		Convey("Should return 01 week", func() {
+			from = fmt.Sprintf("%d", time.Date(2018, 1, 15, 17, 50, 0, 0, time.UTC).UnixNano()/int64(time.Millisecond))
+			to = fmt.Sprintf("%d", time.Date(2018, 1, 15, 17, 55, 0, 0, time.UTC).UnixNano()/int64(time.Millisecond))
+			indexPatternScenario(intervalWeekly, "[data-]GGGG.WW", tsdb.NewTimeRange(from, to), func(indices []string) {
+				So(indices, ShouldHaveLength, 1)
+				So(indices[0], ShouldEqual, "data-2018.03")
+			})
+		})
 	})
 
 	Convey("Hourly interval", t, func() {