istio v1.31.0

VirtualService.spec.http[].route[].headers.request.add.spec.http.mirror

Mirror HTTP traffic to a another destination in addition to forwarding the requests to the intended destination.

VirtualService.spec.http[].route[].headers.request.add.spec.http.mirror fields and descriptions
Field / Type	Description
host `string` required	The name of a service from the service registry.
port `object`	Specifies the port on the host that is being addressed.
subset `string`	The name of a subset within the service.