Will configurations be reloaded when an environment variable changes?

Elastic Stack Beats
1

The current release (5.5) of Filebeat and Metricbeat contain a beta feature that has the beat reload its configuration file when it changes.

It's possible to have these yml files reference environment variables. Will the configuration reload be triggered when a referenced environment variable changes? Or is it only triggered when the timestamp of the yml file itself is updated on save?

2

No. (And processes get a copy of the environment variables when they are started so they don't normally see changes to env vars outside of the process).

It scans the directory periodically and looks for added/removed/updated files. It detects updated files by changes in last modified time.