rest-envoyfilter.yaml

apiVersion: networking.istio.io/v1alpha3
kind: EnvoyFilter
metadata:
  name: inf-auth-gateway-rest
spec:
  workloadLabels:
    app: istio-ingressgateway
  filters:
  - listenerMatch:
      portNumber: 443
      listenerType: GATEWAY
    filterName: envoy.lua
    filterType: HTTP
    insertPosition:
      index: FIRST
    filterConfig:
      inlineCode: |
        function process(request_handle, cluster)

            local authentication_request = {
                [":method"] = "GET",
                [":path"] = "/",
                [":authority"] = request_handle:headers():get(":authority")
            }

            authentication_request["authorization"] = request_handle:headers():get("authorization")

            local response_headers, response_body = request_handle:httpCall(cluster, authentication_request, "", 100)

            if tonumber(response_headers[":status"]) ~= 200 then
                request_handle:respond({[":status"] = response_headers[":status"]}, response_body)
            end

        end

        function envoy_on_request(request_handle)
            process(request_handle, "outbound_.80_._.inf-auth-gateway-rest.x.svc.cluster.local")
        end

        function envoy_on_response(response_handle)
            response_handle:headers():add("x-supported-by", "xring.info")
        end