Owensmallwood/pubdash panel blank when target has no datasource (#52115)

Fixes public dashboards bug. When panel targets have no datasource, the datasource on the panel can be a json object or a string and will get added to the targets for pubdash.

pkg/models/dashboard_queries.go

@@ -10,7 +10,7 @@ func GetUniqueDashboardDatasourceUids(dashboard *simplejson.Json) []string {
 
 	for _, panelObj := range dashboard.Get("panels").MustArray() {
 		panel := simplejson.NewFromAny(panelObj)
-		uid := panel.Get("datasource").Get("uid").MustString()
+		uid := GetDataSourceUidFromJson(panel)
 
 		// if uid is for a mixed datasource, get the datasource uids from the targets
 		if uid == "-- Mixed --" {
@@ -44,8 +44,11 @@ func GroupQueriesByPanelId(dashboard *simplejson.Json) map[int64][]*simplejson.J
 		for _, queryObj := range panel.Get("targets").MustArray() {
 			query := simplejson.NewFromAny(queryObj)
 
+			// if query target has no datasource, set it to have the datasource on the panel
 			if _, ok := query.CheckGet("datasource"); !ok {
-				query.Set("datasource", panel.Get("datasource"))
+				uid := GetDataSourceUidFromJson(panel)
+				datasource := map[string]interface{}{"type": "public-ds", "uid": uid}
+				query.Set("datasource", datasource)
 			}
 
 			panelQueries = append(panelQueries, query)
@@ -61,13 +64,8 @@ func GroupQueriesByDataSource(queries []*simplejson.Json) (result [][]*simplejso
 	byDataSource := make(map[string][]*simplejson.Json)
 
 	for _, query := range queries {
-		dataSourceUid, err := query.GetPath("datasource", "uid").String()
-
-		if err != nil {
-			continue
-		}
-
-		byDataSource[dataSourceUid] = append(byDataSource[dataSourceUid], query)
+		uid := GetDataSourceUidFromJson(query)
+		byDataSource[uid] = append(byDataSource[uid], query)
 	}
 
 	for _, queries := range byDataSource {
@@ -76,3 +74,14 @@ func GroupQueriesByDataSource(queries []*simplejson.Json) (result [][]*simplejso
 
 	return
 }
+
+func GetDataSourceUidFromJson(query *simplejson.Json) string {
+	uid := query.Get("datasource").Get("uid").MustString()
+
+	// before 8.3 special types could be sent as datasource (expr)
+	if uid == "" {
+		uid = query.Get("datasource").MustString()
+	}
+
+	return uid
+}