How do I configure Envoy to use the v3 API?

All bootstrap files are expected to be v3.

For dynamic configuration, we have introduced two new fields to config sources, transport API version and resource API version. The distinction is as follows:

• The transport API version indicates the API endpoint and version of DiscoveryRequest/DiscoveryResponse messages used.

• The resource API version indicates whether a v2 or v3 resource, e.g. v2 RouteConfiguration or v3 RouteConfiguration, is delivered.

The API version must be set for both transport and resource API versions.

If you see a warning or error with V2 (and AUTO) xDS transport protocol versions are deprecated, it is likely that you are missing explicit V3 configuration of the transport API version.