How to install Fluentd plugins on k8s
You will find this article interesting for the begging:Kubernetes Logging and Monitoring: The Elasticsearch, Fluentd, and Kibana (EFK) Stack – Part 1: Fluentd Architecture and Configuration
Also there are a lot of fluentd plugins for kubernetes here: https://www.fluentd.org/plugins/all#stq=kubernetes&stp=1
Each plugin has installation instruction, for example Kubernetes Logging with Fluentd
Also you may want to try Fluent Bit is a lightweight and extensible Log Processor