Separation of backend and frontend

[hashkool]

I was looking at the code for inspiration to make a different UI frontend someday. But it seems that the frontend does some heavy lifting too. What I understand so far:

• the frontend manages its own rules database, by default in memory (unshared?).
• There is some communication with the backend via protobuf, I guess for the permanent rules?

Is there some design document I could look into?

[gustavo-iniguez-goya]

Yeah, right now the systray icon / GUI is integrated with the gRPC server. We could split it, but maybe it'd be better to rewrite it in Go (which I already did sometime ago, several times, but I'll do it one more time https://github.com/gustavo-iniguez-goya/opensnitch/tree/cli/server).

Basically the binary opensnitch-ui creates a gRPC server and exposes several methods: Ping(), AskRule(), Subscribe(), Notifications(), PostAlert() .

When the daemon connects to the server (the GUI), it connects via unix socket or network socket, and calls Subscribe() (ui/client.go). If the connection is sucessful, it sends the configurations + rules, and inititates a bidirectional channel for notifications (ui/notifications.go).

The interepted connections are collected in a circular buffer, and sent to the GUI every second using the Ping() method (ui/client.go , stats/statistics.go).