Add url config parameter

[kdesjard]

For your consideration:

Add a url config parameter to set the fully qualified external url used by the webapp. This allows the server_addr to listen to one address while the url may be used at a load balancer/proxy level.

The url parameter becomes a global static URL via once_cell that can be used to generate fully qualified urls in the various services throughout the app.

I will have subsequent patches to make the feature URL's fully qualified and more OGC compliant.

[pka]

As far as I understand, the already existing public_server_url has the same goal as the url configuration you're adding. This configuration option should probably be returned by bbox_core::endpoints::abs_req_baseurl when defined. Or are there other places you're planning to return a user defined public url?

[kdesjard]

Sorry, I can't believe I missed that. How would I get the public_server_url in datasource/postgis.rs or inventory.rs ?

[pka]

public_server_url is currently only returned in the OpenAPI Yaml or JSON at /openapi. It should be used in all places where the public URL is returned. As I said, using it in bbox_core::endpoints::abs_req_baseurl would cover more endpoints, but there are probable others to implement as well.

[kdesjard]

Looking at the spec and other implementations, the href's in the "links" are absolute.

For example, in postgis.rs's setup_collection, the CoreCollection's ApiLink href:

href: format!("/collections/{id}/items"),

should really be:

href: format!("{public_server_url}/collections/{id}/items"),

There isn't an HttpRequest to pass into abs_req_baseurl.

Thanks, Kris

[pka]

Can you point me to a spec, where you saw this requirement? I've run some OGC conformance tests and they didn't complain! I'm against using absolute URLs in metatdata for the same service since WMS 1.0.

[kdesjard]

Absolute is not a requirement, but I think is more ergonomic for an end-user.

https://docs.ogc.org/is/19-072/19-072.html

"NOTE The href value is not restricted to absolute links. Relative links are also allowed."

However, pygeoapi does it:

https://demo.pygeoapi.io/stable/collections/obs?f=json

and mapserver:

https://demo.mapserver.org/cgi-bin/mapserv/localdemo/ogcapi/collections?f=json

Anyway, maybe it could be a config parameter to use absolute url's?

[pka]

For a human user of the JSON API it's probably more ergonmic, indeed. So you can just click on a link. I'm for using bbox_core::endpoints::abs_req_baseurl wherever possible, since this gives you the correct URL in most cases without configuration. But as you say, setup_collection is a place, where there is no request information yet. Maybe inserting a base URL when delivering collection metadata is not that hard?