The egress.hosts field in Sidecar allows specifying a list of configurations to import. Only configurations matching the specified criteria will be seen by sidecars impacted by the Sidecar resource.
For example:
apiVersion: networking.istio.io/v1kind: Sidecarmetadata: name: defaultspec: egress: - hosts: - "./*" # Import all configuration from our own namespace - "bookinfo/*" # Import all configuration from the bookinfo namespace - "external-services/example.com" # Import only 'example.com' from the external-services namespace