Adding extra Fluentd plugins when using fluentd add-on

Here are below the current Flutend plugins in the Fluentd pod. If we need additional ones, is the recommended way to rebuild the image and add them then?

If yes, is the image coming from https://github.com/fluent/fluentd-kubernetes-daemonset?

cat Gemfile
source 'https://rubygems.org'

gem 'fluentd', '<=1.2.2'
gem 'activesupport', '~>5.2.0'
gem 'fluent-plugin-kubernetes_metadata_filter', '~>2.1.2'
gem 'fluent-plugin-elasticsearch', '~>2.10.5'
gem 'fluent-plugin-systemd', '~>1.0.1'
gem 'fluent-plugin-detect-exceptions', '~>0.0.11'
gem 'fluent-plugin-prometheus', '~>1.0.1'
gem 'fluent-plugin-multi-format-parser', '~>1.0.0'
gem 'oj', '~>3.6.2'

Thanks

Or maybe a follow-up question: is there a public Docker file for rebuilding

Image: k8s.gcr.io/fluentd-elasticsearch:v2.2.0

?