Move client parameter to header

Feature request:

We are adding a client parameter to map instantiation to know who is doing that instantiation. CARTO VL: map?client=vl-0.9.2 CARTO.js: map?js=js-4.0.9

This implies that everytime we publish a new version, the cache invalidates.

As @dgaubert suggested, we should move this to a request header, to be able to gather metrics about who our users are and respect the map cache.

[dgaubert]

You are right. This is a clear Won't fix.

Closing then.

[rochoa]

More reasons to not do this:

1. If we don’t change every layer to be aware of the header, we won’t be able to get the header with the version at the application layer. That means that any intermediate layer (CDN, nginx, varnish) should be aware of that header in order to let it pass. That means adding new functionality to handle the header in all the layers between the browser/client and the application server.
2. If you have to do that, you will be hitting the application layer again. So all the effort to not use a query parameter in the URL will vanish because you have to hit the application layer to be able to log that header. Something you got for granted by just simply using the query parameter.
3. Even more, with the new header, you won’t be able to cache anymore any request because you have to let pass all of them to log them at the application layer.