feat: logs lines support '-' sign means starting log file lines (#365)

cmd/kubevpn/cmds/logs.go

@@ -58,6 +58,6 @@ func CmdLogs(f cmdutil.Factory) *cobra.Command {
 		},
 	}
 	cmd.Flags().BoolVarP(&req.Follow, "follow", "f", false, "Specify if the logs should be streamed.")
-	cmd.Flags().Int32VarP(&req.Lines, "number", "N", 10, "The location is number lines.")
+	cmd.Flags().Int32VarP(&req.Lines, "number", "N", 10, "Lines of recent log file to display.")
 	return cmd
 }

pkg/daemon/action/logs.go

@@ -20,7 +20,11 @@ func (svr *Server) Logs(req *rpc.LogRequest, resp rpc.Daemon_LogsServer) error {
 	}
 
 	// only show latest N lines
-	lines -= req.Lines
+	if req.Lines < 0 {
+		lines = -req.Lines
+	} else {
+		lines -= req.Lines
+	}
 
 	config := tail.Config{Follow: req.Follow, ReOpen: false, MustExist: true, Logger: log.New(io.Discard, "", log.LstdFlags)}
 	if !req.Follow {