How to package and load a file in a backend plugin

I’m creating a backend datasource plugin. To connect to the database, I need to load a certificate from a file. I would like to package that certificate in the plugin. Where do I put the certificate and what path do I need to use to load it?

I can see the plugin runs in /usr/share/grafana, but plugins are in /var/lib/grafana/plugins. Is there some way to obtain the plugin folder?