What is the advantage of using a full blown language for Helm configuration instead just using something, which is a bit more flexible, but not Turing complete like: https://github.com/dhall-lang/dhall-lang (Or something similar)
As Helm so far could operate with a simple template language , and now suddenly jumps to a Turing-complete configuration language - this seems quite large step... What is the justification?
Good question. For 90+% of things a simple template languages works. But, there are cases where you need something more. For example, the features that were baked into Helm v2 to support installing OpenStack in Kubernetes were complex. IIRC, no one on GitHub has used these but they are complicated and in use privately. That complexity should be pushed to the chart rather than Helm. Helm shouldn't need to hold that complexity, which is in the direct line for everyone, for those complicated apps. This is where Lua comes in.
Lua provides the ability to have the language embedded easily (it was designed for that) for use in cross platform situations (Windows included).
As Helm so far could operate with a simple template language , and now suddenly jumps to a Turing-complete configuration language - this seems quite large step... What is the justification?