Interpolate $__interval in backend for alerting with sql datasources (#13156)

add support for interpolate $__interval and  $__interval_ms in sql datasources

pkg/tsdb/postgres/macros.go

@@ -9,18 +9,21 @@ import (
 	"github.com/grafana/grafana/pkg/tsdb"
 )
 
-//const rsString = `(?:"([^"]*)")`;
 const rsIdentifier = `([_a-zA-Z0-9]+)`
 const sExpr = `\$` + rsIdentifier + `\(([^\)]*)\)`
 
 type postgresMacroEngine struct {
+	*tsdb.SqlMacroEngineBase
 	timeRange   *tsdb.TimeRange
 	query       *tsdb.Query
 	timescaledb bool
 }
 
 func newPostgresMacroEngine(timescaledb bool) tsdb.SqlMacroEngine {
-	return &postgresMacroEngine{timescaledb: timescaledb}
+	return &postgresMacroEngine{
+		SqlMacroEngineBase: tsdb.NewSqlMacroEngineBase(),
+		timescaledb:        timescaledb,
+	}
 }
 
 func (m *postgresMacroEngine) Interpolate(query *tsdb.Query, timeRange *tsdb.TimeRange, sql string) (string, error) {
@@ -29,7 +32,7 @@ func (m *postgresMacroEngine) Interpolate(query *tsdb.Query, timeRange *tsdb.Tim
 	rExp, _ := regexp.Compile(sExpr)
 	var macroError error
 
-	sql = replaceAllStringSubmatchFunc(rExp, sql, func(groups []string) string {
+	sql = m.ReplaceAllStringSubmatchFunc(rExp, sql, func(groups []string) string {
 
 		// detect if $__timeGroup is supposed to add AS time for pre 5.3 compatibility
 		// if there is a ',' directly after the macro call $__timeGroup is probably used
@@ -66,23 +69,6 @@ func (m *postgresMacroEngine) Interpolate(query *tsdb.Query, timeRange *tsdb.Tim
 	return sql, nil
 }
 
-func replaceAllStringSubmatchFunc(re *regexp.Regexp, str string, repl func([]string) string) string {
-	result := ""
-	lastIndex := 0
-
-	for _, v := range re.FindAllSubmatchIndex([]byte(str), -1) {
-		groups := []string{}
-		for i := 0; i < len(v); i += 2 {
-			groups = append(groups, str[v[i]:v[i+1]])
-		}
-
-		result += str[lastIndex:v[0]] + repl(groups)
-		lastIndex = v[1]
-	}
-
-	return result + str[lastIndex:]
-}
-
 func (m *postgresMacroEngine) evaluateMacro(name string, args []string) (string, error) {
 	switch name {
 	case "__time":

pkg/tsdb/postgres/postgres_test.go

@@ -43,6 +43,11 @@ func TestPostgres(t *testing.T) {
 			return x, nil
 		}
 
+		origInterpolate := tsdb.Interpolate
+		tsdb.Interpolate = func(query *tsdb.Query, timeRange *tsdb.TimeRange, sql string) (string, error) {
+			return sql, nil
+		}
+
 		endpoint, err := newPostgresQueryEndpoint(&models.DataSource{
 			JsonData:       simplejson.New(),
 			SecureJsonData: securejsondata.SecureJsonData{},
@@ -55,6 +60,7 @@ func TestPostgres(t *testing.T) {
 		Reset(func() {
 			sess.Close()
 			tsdb.NewXormEngine = origXormEngine
+			tsdb.Interpolate = origInterpolate
 		})
 
 		Convey("Given a table with different native data types", func() {
@@ -222,6 +228,40 @@ func TestPostgres(t *testing.T) {
 				}
 			})
 
+			Convey("When doing a metric query using timeGroup and $__interval", func() {
+				mockInterpolate := tsdb.Interpolate
+				tsdb.Interpolate = origInterpolate
+
+				Reset(func() {
+					tsdb.Interpolate = mockInterpolate
+				})
+
+				Convey("Should replace $__interval", func() {
+					query := &tsdb.TsdbQuery{
+						Queries: []*tsdb.Query{
+							{
+								DataSource: &models.DataSource{},
+								Model: simplejson.NewFromAny(map[string]interface{}{
+									"rawSql": "SELECT $__timeGroup(time, $__interval) AS time, avg(value) as value FROM metric GROUP BY 1 ORDER BY 1",
+									"format": "time_series",
+								}),
+								RefId: "A",
+							},
+						},
+						TimeRange: &tsdb.TimeRange{
+							From: fmt.Sprintf("%v", fromStart.Unix()*1000),
+							To:   fmt.Sprintf("%v", fromStart.Add(30*time.Minute).Unix()*1000),
+						},
+					}
+
+					resp, err := endpoint.Query(nil, nil, query)
+					So(err, ShouldBeNil)
+					queryResult := resp.Results["A"]
+					So(queryResult.Error, ShouldBeNil)
+					So(queryResult.Meta.Get("sql").MustString(), ShouldEqual, "SELECT floor(extract(epoch from time)/60)*60 AS time, avg(value) as value FROM metric GROUP BY 1 ORDER BY 1")
+				})
+			})
+
 			Convey("When doing a metric query using timeGroup with NULL fill enabled", func() {
 				query := &tsdb.TsdbQuery{
 					Queries: []*tsdb.Query{