attempt Fluent bit

[rtang03]

https://docs.fluentbit.io/manual/

https://www.youtube.com/watch?v=8jwvg3vgdZk

Simply put, we need a unified logger. Try it.

[rtang03]

In the the default Fluent Bit setting, it outputs to ElasticSearch. For the sake of quicker implementation, I will deploy the in-cluster ElasticSearch and Kibana; instead of original plan using GCP stack driver.

Here will follow the in-cluster EFK stack. And, observe if this stack is good to keep.