AWSDS: Add QueryExecutionError type, prepare 0.32.0 (#205)

Author: idastambuk

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 All notable changes to this project will be documented in this file.
 
+## 0.32.0
+
+- AWSDS: Add QueryExecutionError type
+
 ## 0.31.8
 
 - Bump github.com/grafana/grafana-plugin-sdk-go from 0.265.0 to 0.266.0 in the all-go-dependencies group by @dependabot in https://github.com/grafana/grafana-aws-sdk/pull/204

pkg/awsds/asyncDatasource.go

@@ -119,7 +119,20 @@ func (ds *AsyncAWSDatasource) QueryData(ctx context.Context, req *backend.QueryD
 			var err error
 			frames, err = ds.handleAsyncQuery(ctx, query, req.PluginContext.DataSourceInstanceSettings.UID)
 			if err != nil {
-				response.Set(query.RefID, errorsource.Response(err))
+				errorResponse := errorsource.Response(err)
+				var qeError *QueryExecutionError
+				// checking if we know the cause of downstream error
+				if errors.As(err, &qeError) {
+					errorResponse.Status = backend.StatusInternal
+					switch qeError.Cause {
+						// make sure error.status matches the downstream cause, if provided
+						case QueryFailedInternal:
+							errorResponse.Status = backend.StatusInternal
+						case QueryFailedUser:
+							errorResponse.Status = backend.StatusBadRequest
+						}
+				} 
+				response.Set(query.RefID, errorResponse)
 			} else {
 				response.Set(query.RefID, backend.DataResponse{Frames: frames})
 			}

pkg/awsds/types.go

@@ -47,6 +47,31 @@ const (
 	QueryFailed
 )
 
+type DownstreamErrorCause uint32
+
+const (
+	QueryFailedInternal DownstreamErrorCause = iota
+	QueryFailedUser
+)
+
+// QueryExecutionError error type can be returned from datasource's Execute or QueryStatus methods 
+// this will mark the downstream cause in errorResponse.Status
+type QueryExecutionError struct {
+	Err   error
+	Cause DownstreamErrorCause
+}
+
+func (e *QueryExecutionError) Error() string {
+	if e.Err != nil {
+		return e.Err.Error()
+	}
+	return ""
+}
+
+func (e *QueryExecutionError) Unwrap() error {
+	return e.Err
+}
+
 func (qs QueryStatus) Finished() bool {
 	return qs == QueryCanceled || qs == QueryFailed || qs == QueryFinished
 }