feat: allows resolving relative public urls into absolute urls

[tVienonen]

Hello,

I had an issue with using tileserver-gl running behind a proxy in a subdirectory. I also wanted to configure my web clients with relative urls so that map server url was /maps. Mapbox GL requires that urls that come from tileserver-gl are absolute URLs.

This feature enables the server to serve content from subdirectory so that all the relative urls are resolved into absolute urls.

This is an opt-in feature so it won't be enabled by default. You have to specify TILESERVER_GL_RESOLVE_RELATIVE_PUBLIC_URL=true env variable and public_url option for it to be enabled.

[ochtec]

We have this same issue

[vasily-polonsky]

any updates?