On-demand VHDS and S/RDS Updates¶
The on demand filter can be used to support either on demand VHDS or S/RDS update if configured in the filter chain.
The on-demand update filter can be used to request a virtual host data if it’s not already present in the Route Configuration. The contents of the Host or :authority header is used to create the on-demand request. For an on-demand request to be created, VHDS must be enabled and either Host or :authority header be present.
The on-demand update filter can also be used to request a Route Configuration data if RouteConfiguration is specified to be loaded on demand in the Scoped RouteConfiguration. The contents of the HTTP header is used to find the scope and create the on-demand request.
On-demand VHDS and on-demand S/RDS can not be used at the same time at this point.
This filter should be configured with the name envoy.filters.http.on_demand.
The filter should be placed before envoy.filters.http.router filter in the HttpConnectionManager’s filter chain.