Rerun parsing for the query expression in the experimental functions …

…middleware and remove `GetQueryExpr`

pkg/frontend/querymiddleware/codec.go

@@ -119,13 +119,6 @@ type MetricsQueryRequest interface {
 	GetStep() int64
 	// GetQuery returns the query of the request.
 	GetQuery() string
-	// GetQueryExpr returns the parsed query expression of the request.
-	// Since this returns a pointer, be careful not to use the returned expression in
-	// functions that may mutate it unintentionally and pass the mutated form to the next
-	// middleware, unless that is the intended behavior and we use WithQuery to replace the query.
-	// If you need to mutate the expression temporarily, then reparse the query string
-	// and use that instead of this function.
-	GetQueryExpr() parser.Expr
 	// GetMinT returns the minimum timestamp in milliseconds of data to be queried,
 	// as determined from the start timestamp and any range vector or offset in the query.
 	GetMinT() int64

pkg/frontend/querymiddleware/experimental_functions.go

@@ -58,7 +58,10 @@ func (m *experimentalFunctionsMiddleware) Do(ctx context.Context, req MetricsQue
 		return m.next.Do(ctx, req)
 	}
 
-	expr := req.GetQueryExpr()
+	expr, err := parser.ParseExpr(req.GetQuery())
+	if err != nil {
+		return nil, apierror.New(apierror.TypeBadData, DecorateWithParamName(err, "query").Error())
+	}
 	funcs := containedExperimentalFunctions(expr)
 	if len(funcs) == 0 {
 		// This query does not contain any experimental functions, so we can continue to the next middleware.

pkg/frontend/querymiddleware/model_extra.go

@@ -133,10 +133,6 @@ func (r *PrometheusRangeQueryRequest) GetQuery() string {
 	return ""
 }
 
-func (r *PrometheusRangeQueryRequest) GetQueryExpr() parser.Expr {
-	return r.queryExpr
-}
-
 // GetMinT returns the minimum timestamp in milliseconds of data to be queried,
 // as determined from the start timestamp and any range vector or offset in the query.
 func (r *PrometheusRangeQueryRequest) GetMinT() int64 {
@@ -317,10 +313,6 @@ func (r *PrometheusInstantQueryRequest) GetQuery() string {
 	return ""
 }
 
-func (r *PrometheusInstantQueryRequest) GetQueryExpr() parser.Expr {
-	return r.queryExpr
-}
-
 func (r *PrometheusInstantQueryRequest) GetStart() int64 {
 	return r.GetTime()
 }

pkg/frontend/querymiddleware/remote_read.go

@@ -281,10 +281,6 @@ func (r *remoteReadQueryRequest) GetQuery() string {
 	return r.promQuery
 }
 
-func (r *remoteReadQueryRequest) GetQueryExpr() parser.Expr {
-	return nil
-}
-
 func (r *remoteReadQueryRequest) GetHeaders() []*PrometheusHeader {
 	return nil
 }