My app consists of two containers: the app itself and a database. I'm planning to wrap the app into a chart, thus paving a way for easy reproducible deployment.
Apart from setting/reading environment envs (which helm+kubernetes seems to handle really well), part of app's configuration is:
making sure the database is pre-filled with special auxiliary data (e.g. admin user exists, some user role names required to create new users are there, etc.).
I like the idea of having readable yaml files hold the entire configuration in a human readable format. However at a glance it doesn't seem that helm in any way would help with this (DB records) kind of configuration.
That being said, what is the best place to put code/configuration ensuring that DB contains certain auxiliary records? A config yaml file? An container init script, written in bash?
You are right, Kubernetes or Helm cannot help with preparing your pre-filled database records/schema.
You should probably have your application initialize those pre-filled data. If you don't want to put this logic into your application, you can ship an initialization script and configure an init container with Kubernetes.
Kubernetes makes sure every time your application container is restarted, the init container runs first. In the init container, you can execute a bash/python/... script that makes sure the records you want are there.