Right now service names/addresses like `sql-mariadb-secondary.default.svc.cluster.local` in our values files.
This means the same string is repeated in multiple places.
We may want to read these from a shared place.
We should consider the pros and cons, and see what this would look like.
This probably also involves the investigation of `base` layers for our helmfile, that we don't use yet.
https://github.com/roboll/helmfile
```
#
# Advanced Configuration: Layering
#
# Helmfile merges all the "base" state files and this state file before processing.
#
# Assuming this state file is named `helmfile.yaml`, all the files are merged in the order of:
# environments.yaml <- defaults.yaml <- templates.yaml <- helmfile.yaml
bases:
- environments.yaml
- defaults.yaml
- templates.yaml
```