Client-Delegating MapML Proxy

[prushforth]

Background

GeoServer has the capability to use a remote WMS or WMTS as a data store and will “cascade” requests received by the local GeoServer to the back-end service, acting as an intermediary or proxy for every client request. In such a cascading configuration, load is incurred on the local GeoServer instance for receiving, processing (acting as a WMS or WMTS client of the remote service) and responding to client requests.

Requirement

Add the option to choose, in the MapML publishing panel for Layers (not in the Layer Group panel, since they are composed of local/remote layers), for a remote (proxied) WMS or WMTS service (Store) requested of the local GeoServer as a MapML response via GetMap, whether the link templates embedded in MapML will refer to the local GeoServer instance (currently this is the only option, with all load falling on the local GeoServer) or to the remote WMS or WMTS i.e. the only load that goes to GeoServer will be the initial GetMap request for MapML. This option will greatly improve the proxying ability of GeoServer by removing all but the first GetMap request from client mapping sessions.