The "you don't want a full programming language" trope I see repeated a lot but I think far more people end up wishing for a Turing complete language than wishing it _wasn't_ Turing complete.
They do, until a configuration endless loop brings down their production system.
This is not really different than C vs Rust, or even Perl regular expressions (unbounded execution time) vs real regular expression. With great powers comes great abilities to shoot yourself in the foot.
The power/guarantee balance is delicate, and you can’t hold the stick at both ends. People will always complain.
This is exactly what the Starlark language was developed to solve, initially for Bazel but also used other places. It's a "full scripting language" but intentionally doesn't (in default configuration) support recursion or unbounded loops, so is deterministic and bounded execution time. I really wish more projects would reach for it as a configuration language.
I have such mixed feelings about Starlark and Bazel macros. When I write Bazel macros, they're great, the perfect tool for the job. When I encounter macros written by someone else, they are awful, a mistake and the bane of my existence.
In the same way that it's possible to have an xml/json/yaml/toml config that creates despair in those who have to maintain it, a python or bash script can grow into a monster in the basement.
Or, it could be a cogent script that makes its intent and operation obvious. I prefer that when possible.
The environment around the language can put in limits (on time, number of operations, etc.)
Convex does this well, replacing SQL (somewhat yaml-like sucky old declarative language) with JS/TS but in a well-locked-down environment with limits to ensure one mutation or query doesn’t take down the whole DB.
The number of times I've seen a configuration endless loop bring down anything are so few compared to the time wasted on DSLs and having to bend over backwards to do things a first-class programming language can do simply. Same with PCRE I've seen that maybe.. once.
This is not really different than C vs Rust, or even Perl regular expressions (unbounded execution time) vs real regular expression. With great powers comes great abilities to shoot yourself in the foot.
The power/guarantee balance is delicate, and you can’t hold the stick at both ends. People will always complain.