Review missing timeouts

[josecelano]

Relates to: torrust/torrust-tracker#603

I've opened this issue to collect and track all past, current and future problems related to timeouts.

I'm going to describe here some places potentially affected by this type of issue.

Potentially affected code

Healthcheck binary

• Add timeout to the http_health_check binary #433

Index API Server

It uses Axum. All services using Axum have the same problem. For more info see:

• API: Add timeouts for client requests to avoid DoS attack #204

Index API Client

The Index API client does not have timeouts.

• Index API client: add timeout to requests #472

Client: https://github.com/torrust/torrust-index/blob/develop/src/web/api/client/v1/client.rs

That leads to some problems like the one described here. The seeder command uses the Index API to upload random torrents (for testing purposes).

Sometimes a request waits forever. We should add a timeout to the client and retry later. I do not know why the server is not responding. That's a different problem.

Tracker API Client

The Index API client does not have timeouts.

• Tracker API client: add timeout to requests #473

Client: https://github.com/torrust/torrust-index/blob/develop/src/tracker/api.rs

Image Proxy

let reqwest_client = reqwest::Client::builder()
    .timeout(Duration::from_millis(settings.image_cache.max_request_timeout_ms))
    .build()
    .expect("unable to build client request");

It already has the timeout:

[image_cache]
max_request_timeout_ms = 1000
...

cc @WarmBeer @da2ce7