Better error handling for empty server responses (#1741)

Author: prashantkumar1982

observability-lib/grafana/datasource.go

@@ -1,6 +1,10 @@
 package grafana
 
-import "github.com/smartcontractkit/chainlink-common/observability-lib/api"
+import (
+	"errors"
+
+	"github.com/smartcontractkit/chainlink-common/observability-lib/api"
+)
 
 type DataSource struct {
 	ID   uint
@@ -26,6 +30,9 @@ func GetDataSourceFromGrafana(name string, grafanaURL string, grafanaToken strin
 	if err != nil {
 		return nil, err
 	}
+	if datasource.Name == "" {
+		return nil, errors.New("unexpected empty response. please check connection or vpn settings")
+	}
 
 	return &DataSource{ID: datasource.ID, Name: datasource.Name, UID: datasource.UID, Type: datasource.Type}, nil
 }