Error 404 and report if app plan doesn't match

nginx.conf

location = /threescale_report {
  internal;
  set $provider_key "PROVIDERKEY";

  proxy_pass http://threescale_backend/transactions.xml;
  proxy_set_header  Host  "su1.3scale.net";
}

nginx.lua

--------------------------------------
-- authrep ---------------------------
--------------------------------------
function authrep(params, service)
  ngx.var.cached_key = ngx.var.cached_key .. ":" .. ngx.var.usage
  local api_keys = ngx.shared.api_keys
  local is_known = api_keys:get(ngx.var.cached_key)

  if is_known ~= 200 then
    local res = ngx.location.capture("/threescale_authrep", { share_all_vars = true })

    -- IN HERE YOU DEFINE THE ERROR IF CREDENTIALS ARE PASSED, BUT THEY ARE NOT VALID
    if res.status ~= 200 then
      -- remove the key, if it's not 200 let's go the slow route, to 3scale's backend
      api_keys:delete(ngx.var.cached_key)
      ngx.status = res.status
      ngx.header.content_type = "application/json"
      error_authorization_failed(service)
    else
      -- check for application plan in authrep response
      local qa_plan = ngx.re.match(res.body,[=[<plan>.+QA]=])

      if not qa_plan then
        -- if application plan is not "Sandbox" report
        -- to 3scale and return 404 error to the client
        local transaction = "transactions[0][app_id]=" .. params.app_id ..
                            "&transactions[0][usage][hits]=1"

        local report_body = "provider_key=" .. ngx.var.provider_key ..
                            "&service_id=" .. ngx.var.service_id ..
                            "&transactions=" .. transaction

        ngx.location.capture("/threescale_report", {
          method = ngx.HTTP_POST,
          body = report_body,
          share_all_vars = true
        })
        error_no_match(service)
      end

      api_keys:set(ngx.var.cached_key,200)
    end
      ngx.var.cached_key = nil
  end
end