SSE: Use errutil to show better error messages in prod (#71658)

- include public message
- propagate data source query errors so they are shown as well to which fixes #70026

pkg/expr/errors.go

@@ -0,0 +1,58 @@
+package expr
+
+import (
+	"errors"
+
+	"github.com/grafana/grafana/pkg/util/errutil"
+)
+
+var ConversionError = errutil.NewBase(
+	errutil.StatusBadRequest,
+	"sse.readDataError",
+).MustTemplate(
+	"[{{ .Public.refId }}] got error: {{ .Error }}",
+	errutil.WithPublic(
+		"failed to read data from from query {{ .Public.refId }}: {{ .Public.error }}",
+	),
+)
+
+func MakeConversionError(refID string, err error) error {
+	data := errutil.TemplateData{
+		// Conversion errors should only have meta information in errors
+		Public: map[string]interface{}{
+			"refId": refID,
+			"error": err.Error(),
+		},
+		Error: err,
+	}
+	return ConversionError.Build(data)
+}
+
+var QueryError = errutil.NewBase(
+	errutil.StatusBadRequest, "sse.dataQueryError").MustTemplate(
+	"failed to execute query [{{ .Public.refId }}]: {{ .Error }}",
+	errutil.WithPublic(
+		"failed to execute query [{{ .Public.refId }}]: {{ .Public.error }}",
+	))
+
+func MakeQueryError(refID, datasourceUID string, err error) error {
+	var pErr error
+	var utilErr errutil.Error
+	// See if this is grafana error, if so, grab public message
+	if errors.As(err, &utilErr) {
+		pErr = utilErr.Public()
+	} else {
+		pErr = err
+	}
+
+	data := errutil.TemplateData{
+		Public: map[string]interface{}{
+			"refId":         refID,
+			"datasourceUID": datasourceUID,
+			"error":         pErr.Error(),
+		},
+		Error: err,
+	}
+
+	return QueryError.Build(data)
+}