People keep hacking up YAML with templating to produce a configuration language which is a bad solution (see for example https://leebriggs.co.uk/blog/2019/02/07

People keep hacking up YAML with templating to produce a configuration language which is a bad solution (see for example https://leebriggs.co.uk/blog/2019/02/07/why-are-we-templating-yaml https://leebriggs.co.uk/blog/2019/02/07/why-are-we-templatin...). The problem is that the people who are using templated YAML don't really want to learn a full-blown language since the vast majority of them never, ever want to write a compiler or a highly concurrent HTTP server. They definitely don't care about functional programming or want to know what a monad is or want to have to learn about first class functions and closures or async/await. They just want a pretty trivial language that you can learn in a weekend or two. The kind of necessary complexity that you might 'add' to such a language before anything else is making it side-effect free so that you can't alter the running state of the system in the language and the purpose is to render a YAML/JSON/TOML config to feed as declarative config into tools like terraform. That focus is much different from a programming language which gives you the ability to execve() arbitrary commands and comes with concurrency primitives that templated-YAML users just don't care about at all. When you look at it from the perspective of someone who already knows a computer language well it doesn't seem useful, but the point is to address the users who don't know any computer languages particularly well. And 24 years ago I thought we needed to just use general purpose computer languages and turn system administrators into programmers (or fire the ones that wouldn't learn) but that has clearly never happened, and we're retaining the less-technical-than-SWE roles who manage infrastructure, although its now DevOps people managing k8s with YAML. If just using a general purpose language met the social needs that we have then it would have happened already. The existence of templated YAML and its overwhelming success proves that there's a need that has to be met. I'm still skeptical that any of these configuration management languages is thinking clearly about what need is driving templated YAML though, but its nice that there's an explosion of them so that hopefully sooner or later one of them will really stick and become popular.