I've recently been dipping my toes into k8s / kustomize / helm, and I recently had a situation where having a base deployment yml template that I wanted to reuse across various deployments. I had a look at Helm and I was frankly shocked how bad the templating was with Go templates, it was close to unreadable and felt very brittle!

Yeah, that's fair. I don't think it's as bad if you make your own charts and can more liberally hardcode things. Community charts tend to have an insane amount of "knobs" so you can basically change everything being templated.

I don't know if I'd necessarily call it brittle, though. You can use `helm template` and various linters to validate the generated yaml is correct (and use something like pre-commit to autorun)

How so? I find it much the same to other templating engines like Jinja, though I'm definitely not a fan of the syntax. But that hardly matters anymore with LLMs.

Specifically with YAML, Go templating requires some special operators to get anything useful done and it ends up being an unreadable mess.

I think it's a combination of text templating + yaml (which is whitespace delimited). When templating html with Jinja, it's not a big deal if the indentation isn't right. In helm, best case you get a syntax error, worst case you end up overwriting keys and producing something syntactically but not logically correct.

I did that too, and ended up just skipping helm and using envsubst to interpolate the values I need at runtime from env vars. Nearly everyone preferred that approach. YMMV of course.

I think that's a good approach if it works for your use case. Sometimes you might want something slightly more sophisticated like basic logic (loops/conditionals). In those cases, you can still use helm but you have an extremely simple template and avoid many of the "can't read this template" helm pitfalls.

BTW, this is what Flux V2 (GitOps) supports as well and we do at our company. It's worked well and covered almost all our use cases.

Shared up the chain, but bringing your attention to it as well: https://nixidy.dev/ solves all of these issues.