Provide periodic detection updating of the ipfs daemon's running status from the replay web UI

[machawk1]

No description provided.

[ibnesayeed]

For things like this we can use SSE to update the number of captures, progress of indexing, status of the IPFS daemon and whatnot on the client side. No need to poll.

[machawk1]

@ibnesayeed I would prefer to make this feature as light as possible initially on our end. We don't control the response from the ipfs daemon's HTTP API. The idea is to solely get the status of the daemon with this ticket then maybe more information about the node once we are confident of ipwb replay to ipfs daemon communication.

[ibnesayeed]

I am not suggesting to talk to the IPFS daemon from the client/browser. Our IPWB server should detect and keep the state info somewhere and tell the client using SSE when necessary. The only thing I am suggesting here to change is not to use periodic polling, but let the server tell the client instead.

[machawk1]

Ah, ok, so (ipwb replay web ui)←SSE→(ipwb replay backend)↔(ipfs daemon)?

[ibnesayeed]

SSE is not a separate animal. The client (web UI) connects to the backend (IPWB server) and starts listening on a channel. Each time the backend finds something worth telling the client, it simply emits an event data on that channel which can then be received by the client and acted upon (update pieces of information on the page). After the initial connection, it is a one-way communication, that is why it is called a Server Sent Event.

[machawk1]

SSE is not a separate animal

@ibnesayeed I am aware of this. I meant to convey communication via SSE, not that SSE was an entity in itself. Thanks for the suggestions.