Q:

fluent plugin kafka json escaping

I am using version fluent-plugin-kafka version 0.12.3. 
I have an application that outputs its logs in JSON format, but my console consumer shows that the logs are escaped. 
for instance, the application output the following log line:
{
  "msg": "ok"
}

when i look at the log using the console consumer, it outputs:
{
  "container_id": "7e...",
  "container_name": "/app",
  "source": "stdout",
  "log": "{\"msg\": \"ok\"}"
}

how should fluent-plugin-kafka should be configured so the application log will be nested as a json without escaping it? 
desired output:
{
  "container_id": "7e...",
  "container_name": "/app",
  "source": "stdout",
  "log": {
    "msg": "ok"
  }
}

A:

using record transformer filter i was able to mutate the incoming data.