Elasticsearch: Add support for Elasticsearch 8.0 (Beta) (#41729)

* use fixed_interval in date_histogram

* Add 8.0 to available versions in datasource settings

* Remove moving_avg from available metric aggregations

* Add ES8 devenv

* Update public/app/plugins/datasource/elasticsearch/components/QueryEditor/MetricAggregationsEditor/utils.ts

Co-authored-by: Piotr Jamróz <pm.jamroz@gmail.com>

* Add FE tests

* Add BE test

* fix FE test

* fix BE test

Co-authored-by: Piotr Jamróz <pm.jamroz@gmail.com>

pkg/tsdb/elasticsearch/client/models.go

@@ -239,6 +239,7 @@ type HistogramAgg struct {
 type DateHistogramAgg struct {
 	Field          string          `json:"field"`
 	Interval       string          `json:"interval,omitempty"`
+	FixedInterval  string          `json:"fixed_interval,omitempty"`
 	MinDocCount    int             `json:"min_doc_count"`
 	Missing        *string         `json:"missing,omitempty"`
 	ExtendedBounds *ExtendedBounds `json:"extended_bounds"`

pkg/tsdb/elasticsearch/client/search_request.go

@@ -342,6 +342,11 @@ func (b *aggBuilderImpl) DateHistogram(key, field string, fn func(a *DateHistogr
 		fn(innerAgg, builder)
 	}
 
+	if b.version.Major() >= 8 {
+		innerAgg.FixedInterval = innerAgg.Interval
+		innerAgg.Interval = ""
+	}
+
 	b.aggDefs = append(b.aggDefs, aggDef)
 
 	return b

pkg/tsdb/elasticsearch/time_series_query_test.go

@@ -1049,6 +1049,62 @@ func TestSettingsCasting(t *testing.T) {
 
 			assert.Equal(t, 10, dateHistogramAgg.MinDocCount)
 		})
+
+		t.Run("interval parameter", func(t *testing.T) {
+			t.Run("Uses interval with ES < 8.0.0", func(t *testing.T) {
+				c := newFakeClient("7.7.0")
+				_, err := executeTsdbQuery(c, `{
+					"timeField": "@timestamp",
+					"bucketAggs": [
+						{
+							"type": "date_histogram",
+							"field": "@timestamp",
+							"id": "2",
+							"settings": {
+								"interval": "1d"							
+							}
+						}
+					],
+					"metrics": [
+						{ "id": "1", "type": "average", "field": "@value" }
+					]
+				}`, from, to, 15*time.Second)
+				assert.Nil(t, err)
+				sr := c.multisearchRequests[0].Requests[0]
+
+				dateHistogramAgg := sr.Aggs[0].Aggregation.Aggregation.(*es.DateHistogramAgg)
+
+				assert.Zero(t, dateHistogramAgg.FixedInterval)
+				assert.NotZero(t, dateHistogramAgg.Interval)
+			})
+
+			t.Run("Uses fixed_interval with ES >= 8.0.0", func(t *testing.T) {
+				c := newFakeClient("8.0.0")
+				_, err := executeTsdbQuery(c, `{
+					"timeField": "@timestamp",
+					"bucketAggs": [
+						{
+							"type": "date_histogram",
+							"field": "@timestamp",
+							"id": "2",
+							"settings": {
+								"interval": "1d"							
+							}
+						}
+					],
+					"metrics": [
+						{ "id": "1", "type": "average", "field": "@value" }
+					]
+				}`, from, to, 15*time.Second)
+				assert.Nil(t, err)
+				sr := c.multisearchRequests[0].Requests[0]
+
+				dateHistogramAgg := sr.Aggs[0].Aggregation.Aggregation.(*es.DateHistogramAgg)
+
+				assert.NotZero(t, dateHistogramAgg.FixedInterval)
+				assert.Zero(t, dateHistogramAgg.Interval)
+			})
+		})
 	})
 
 	t.Run("Inline Script", func(t *testing.T) {