HOWTOBUILD.md does not work as described when installing plugins

[steros]

Describe the bug

When following HOWTOBUILD.md fluentd stops with an unknown plugin error.

To Reproduce

Follow HOWTOBUILD.md use debian v1.17

Expected behavior

Fluentd starts properly with recognizing the installed plugin

Your Environment

- Tag of using fluentd-docker-image: fluent/fluentd:v1.17-debian-1

Your Configuration

Just see HOWTOBUILD.md

Your Error Log

config error file="/fluentd/etc/fluent.conf" error_class=Fluent::NotFoundPluginError error="Unknown output plugin 'elasticsearch'. Run 'gem search -rd fluent-plugin' to find plugins"

Additional context

No response

[kenhys]

It might be a bit outdated sample in HOWTOBUILD.md debian's Dockefile example FROM:, at least Fluent::NotFoundPluginError is not reproducible for me.

Could you copy & paste your customized Dockefile and command line when launching that image, please?