Fix: GCP pubsub / cloud tasks metric queries for metric scoped projec…

…ts (#5258)

CHANGELOG.md

@@ -78,6 +78,7 @@ Here is an overview of all new **experimental** features:
 - **General**: Fix otelgrpc DoS vulnerability ([#5208](https://github.com/kedacore/keda/issues/5208))
 - **General**: Prevented stuck status due to timeouts during scalers generation ([#5083](https://github.com/kedacore/keda/issues/5083))
 - **Azure Pipelines**: No more HTTP 400 errors produced by poolName with spaces ([#5107](https://github.com/kedacore/keda/issues/5107))
+- **GCP pubsub scaler**: Added `project_id` to filter for metrics queries ([#5256](https://github.com/kedacore/keda/issues/5256))
 - **GCP pubsub scaler**: Missing use of default value of `value` added ([#5093](https://github.com/kedacore/keda/issues/5093))
 - **ScaledJobs**: Copy ScaledJob annotations to child Jobs ([#4594](https://github.com/kedacore/keda/issues/4594))
 

pkg/scalers/gcp_stackdriver_client.go

@@ -184,25 +184,31 @@ func (s StackDriverClient) GetMetrics(
 
 	// Create a request with the filter and the GCP project ID
 	var req = &monitoringpb.ListTimeSeriesRequest{
-		Filter: filter,
 		Interval: &monitoringpb.TimeInterval{
 			StartTime: &timestamppb.Timestamp{Seconds: startTime.Unix()},
 			EndTime:   &timestamppb.Timestamp{Seconds: endTime.Unix()},
 		},
 		Aggregation: aggregation,
 	}
 
+	// Set project to perform request in and update filter with project_id
 	switch projectID {
 	case "":
 		if len(s.projectID) > 0 {
 			req.Name = "projects/" + s.projectID
+			filter += ` AND resource.labels.project_id="` + s.projectID + `"`
 		} else {
 			req.Name = "projects/" + s.credentials.ProjectID
+			filter += ` AND resource.labels.project_id="` + s.credentials.ProjectID + `"`
 		}
 	default:
 		req.Name = "projects/" + projectID
+		filter += ` AND resource.labels.project_id="` + projectID + `"`
 	}
 
+	// Set filter on request
+	req.Filter = filter
+
 	// Get an iterator with the list of time series
 	it := s.metricsClient.ListTimeSeries(ctx, req)