Workload labels not working (restrict filter to service)

1

Hello Istio,

I am trying to implement envoy filters in our environment to handle header manipulation for various microservices but we are not able to use “workloadLabels” to make that application(service) specific. I am applying it at gateway level due to which even a small load is breaking the call flow.

Here is the config I am using:

apiVersion: networking.istio.io/v1alpha3
kind: EnvoyFilter
metadata:
  name: envoy-filter-relqa
  namespace: mui-relqa
spec:
  filters:
  - listenerMatch:
      portNumber: 443
      listenerType: GATEWAY
    filterName: envoy.lua
    filterType: HTTP
    insertPosition:
      index: FIRST
    filterConfig:
      inlineCode: |
        function envoy_on_request(request_handle)
          local path= request_handle:headers():get(":path");
          if path~="/health" then

            local cookie= request_handle:headers():get("cookie")
            local token= request_handle:headers():get("access_token");
            local user= request_handle:headers():get("user-agent");

            if string.match(path,"/api/checkout") then
            request_handle:logWarn("inside checkout service")
              if token then
                if token~="true" then
                  request_handle:logWarn("Access token in the header")
                  request_handle:logWarn(request_handle:headers():get("access_token"))
                  request_handle:headers():replace("access_token",token)
                end
              end
              if cookie then
                request_handle:logWarn("Access token in the Cookie")
                request_handle:logWarn(cookie)
                cookietoken(cookie,";",request_handle,"=");
              end
            end

We have multiple such “if” conditions mentioned above (actually one “if” condition for each microservice in single EnvoyFilter)

Please let me know if you have any suggestions to optimize this to make istio scan the filter faster, which I guess it does for each an every call.