Handle ds init errors

pkg/datasource.go

@@ -164,6 +164,16 @@ func readZabbixSettings(dsInstanceSettings *backend.DataSourceInstanceSettings)
 		return nil, err
 	}
 
+	if zabbixSettingsDTO.TrendsFrom == "" {
+		zabbixSettingsDTO.TrendsFrom = "7d"
+	}
+	if zabbixSettingsDTO.TrendsRange == "" {
+		zabbixSettingsDTO.TrendsRange = "4d"
+	}
+	if zabbixSettingsDTO.CacheTTL == "" {
+		zabbixSettingsDTO.CacheTTL = "1h"
+	}
+
 	trendsFrom, err := gtime.ParseInterval(zabbixSettingsDTO.TrendsFrom)
 	if err != nil {
 		return nil, err
@@ -202,6 +212,7 @@ func (ds *ZabbixDatasource) GetDatasource(pluginContext backend.PluginContext) (
 
 	ds.logger.Debug(fmt.Sprintf("Datasource cache miss (Org %d Id %d '%s' %s)", pluginContext.OrgID, dsSettings.ID, dsSettings.Name, dsInfoHash))
 
+	ds.logger.Debug("DS config", "settings", pluginContext.DataSourceInstanceSettings)
 	dsInstance, err := ds.NewZabbixDatasource(pluginContext.DataSourceInstanceSettings)
 	if err != nil {
 		ds.logger.Error("Error initializing datasource", "error", err)

pkg/resource_handler.go

@@ -37,6 +37,11 @@ func (ds *ZabbixDatasource) zabbixAPIHandler(rw http.ResponseWriter, req *http.R
 
 	pluginCxt := httpadapter.PluginConfigFromContext(req.Context())
 	dsInstance, err := ds.GetDatasource(pluginCxt)
+	if err != nil {
+		ds.logger.Error("Error loading datasource", "error", err)
+		WriteError(rw, http.StatusInternalServerError, err)
+		return
+	}
 
 	apiReq := &ZabbixAPIRequest{Method: reqData.Method, Params: reqData.Params}
 

pkg/zabbix_api.go

@@ -29,14 +29,14 @@ func (ds *ZabbixDatasourceInstance) ZabbixQuery(ctx context.Context, apiReq *Zab
 	cachedResult, queryExistInCache := ds.queryCache.Get(requestHash)
 	if !queryExistInCache {
 		resultJson, err = ds.ZabbixRequest(ctx, apiReq.Method, apiReq.Params)
+		if err != nil {
+			return nil, err
+		}
 
 		if _, ok := NotCachedMethods[apiReq.Method]; !ok {
 			ds.logger.Debug("Write result to cache", "method", apiReq.Method)
 			ds.queryCache.Set(requestHash, resultJson)
 		}
-		if err != nil {
-			return nil, err
-		}
 	} else {
 		var ok bool
 		resultJson, ok = cachedResult.(*simplejson.Json)