This config entry will be used to configure terminating gateways.
It accepts the name of the gateway and a list of services the gateway will represent.
For each service users will be able to specify: its name, namespace, and additional options for TLS origination.
Co-authored-by: Kyle Havlovitz <kylehav@gmail.com>
Co-authored-by: Chris Piraino <cpiraino@hashicorp.com>