Update Stackdriver Exporter insecure trace and monitoring clients

Exporter now explicitly connects with insecure connections.

Author: dinooliva

exporter/stackdriverexporter/stackdriver.go

@@ -89,13 +89,17 @@ func newStackdriverExporter(cfg *Config) (*stackdriver.Exporter, error) {
 		DefaultMonitoringLabels: &stackdriver.Labels{},
 	}
 	if cfg.Endpoint != "" {
-		dOpts := []option.ClientOption{}
 		if cfg.UseInsecure {
-			dOpts = append(dOpts, option.WithGRPCDialOption(grpc.WithInsecure()))
+			conn, err := grpc.Dial(cfg.Endpoint, grpc.WithInsecure())
+			if err != nil {
+				return nil, fmt.Errorf("cannot configure grpc conn: %v", err)
+			}
+			options.TraceClientOptions = []option.ClientOption{option.WithGRPCConn(conn)}
+			options.MonitoringClientOptions = []option.ClientOption{option.WithGRPCConn(conn)}
+		} else {
+			options.TraceClientOptions = []option.ClientOption{option.WithEndpoint(cfg.Endpoint)}
+			options.MonitoringClientOptions = []option.ClientOption{option.WithEndpoint(cfg.Endpoint)}
 		}
-		dOpts = append(dOpts, option.WithEndpoint(cfg.Endpoint))
-		options.TraceClientOptions = dOpts
-		options.MonitoringClientOptions = dOpts
 	}
 	if cfg.NumOfWorkers > 0 {
 		options.NumberOfWorkers = cfg.NumOfWorkers