custom lambda plugin kong

req.lua

local res, err = client:request {
    method = "POST",
    path = request.url,
    body = request.body,
    headers = request.headers
  }
  if not res then
    return responses.send_HTTP_INTERNAL_SERVER_ERROR(err)
  end
 
  local body = res:read_body()
  local json_body = cjson.decode(body)
  local headers = res.headers

  local ok, err = client:set_keepalive(conf.keepalive)
  if not ok then
    return responses.send_HTTP_INTERNAL_SERVER_ERROR(err)
  end

  if conf.unhandled_status
     and headers["X-Amz-Function-Error"] == "Unhandled"
  then
    ngx.status = conf.unhandled_status

  else
    ngx.status = res.status
  end

  -- Send response to client
  for k, v in pairs(headers) do
    ngx.header[k] = v
  end
  

  return responses.send_HTTP_OK(json_body, headers)