Follow index redirect in discovery

[nielsvanvelzen]

Sometimes people use a baseurl and only have a redirect on the index page (e.g. jellyfin.local -> jellyfin.local/jellyfin). We should support these redirects to allow easier setup in Jellyfin clients.

[AllegraCodes]

I'd like to take this.

Just to be clear, when you say the path should be added to the candidates, should that replace the existing candidates so we only check candidates with the redirected path, or should candidates with the path be checked in addition to the existing candidates, possibly with an increased score?

[nielsvanvelzen]

The AddressCandidateHelper is the is the "helper" that clients can use to convert user-input to actual server addresses. It's a synchronous API and does not make network calls.

The RecommendedServerDiscovery is used to test a list of servers (commonly those outputted from AddressCandidateHelper) by connecting to them and validating the responses.

I would expect the RecommendedServerDiscovery follows redirects and decreases the score slightly (to prefer non-redirected URL's above redirected URL's). The returned RecommendedServerInfo should have a way to indicate it was redirected from the original input, perhaps by adding both the original and final addresses with a getter "isRedirected" that compares them.

The discover function should have a parameter "followRedirects", similar to the option in HttpClientOptions.

[AllegraCodes]

Behavior can be tested with our own demo server which redirects to the /stable path.

This doesn't work with the demo site currently as it redirects to stable/web/ instead of just stable/

[nielsvanvelzen]

I've been told we're using a baseurl configuration on demo.jellyfin.org so it will indeed redirect to /stable/web/. So it is not suitable to test this behavior with.