---
apiVersion: networking.istio.io/v1alpha3
kind: EnvoyFilter
metadata:
  name: xff-filter
spec:
  workloadLabels:
    app: <my_app_name>
  filters:
    - listenerMatch:
        portNumber: 443
        listenerProtocol: HTTP
        listenerType: ANY
      filterName: envoy.lua
      filterType: HTTP
      filterConfig:
        inlineCode: |
          function envoy_on_request(request_handle)
            local xff_header = request_handle:headers():get("X-Forwarded-For")
            local first_ip = string.gmatch(xff_header, "(%d+.%d+.%d+.%d+)")();
            request_handle:headers():add("X-Cust-User-IP", first_ip);
          end