envoyfilter-bodysizelimit-with-lua.yml

apiVersion: networking.istio.io/v1alpha3
kind: EnvoyFilter
metadata:
  name: filter-buffersize-limit
  namespace: istio-system
spec:
  workloadSelector:
    labels:
      istio: ingressgateway
  configPatches:
    - applyTo: HTTP_FILTER
      match:
        context: GATEWAY
        listener:
          filterChain:
            filter:
              name: "envoy.filters.network.http_connection_manager"
              subFilter:
                name: "envoy.filters.http.router"
      patch:
        operation: INSERT_BEFORE
        value: # lua filter specification
          name: envoy.lua
          typed_config:
              "@type": "type.googleapis.com/envoy.extensions.filters.http.lua.v3.Lua"
              inlineCode: |
                function envoy_on_request(request_handle)
                  request_handle:logInfo("Aidan Path: "..request_handle:headers():get(":path"))
                  body_size = request_handle:body():length()
                  if (body_size > 4) then
                    request_handle:logInfo("body_size is bigger than 4")
                    request_handle:respond({ [":status"] = "413" })
                  else
                    print("good size")
                  end
                  request_handle:headers():add("request-body-size", tostring(body_size))
                end
                function envoy_on_response(response_handle)
                  body_size = response_handle:body():length()
                  response_handle:headers():add("response-body-size", tostring(body_size))
                end