isopod VS sprig

Tried it[0], worked reasonably well. Be prepared for strong opposition from traditional “devops” folks “who don’t mind yaml” and will drag everyone down.

[0] - https://github.com/cruise-automation/isopod

I like Cue and Jsonnet and Starlark and so on. But all of these have very low mindshare (though Starlark has the most momentum thanks to Bazel), and who knows if they will be dead by next year.

Being an early adopter is difficult both in terms of the immaturity of the tooling — Cue, for example, only has a Go implementation at the moment — and in terms of the risk of betting on an evolutionary dead end, which can cause a lot of unnecessary churn when you want to standardize on something across an entire organization.

As a concrete example, I'd love to replace Kubernetes's use of YAML with something like the above. But the tooling is immature, and almost nobody is using any of it. For example, there's Isopod [1], which is a nice-looking tool to use Starlark with Kubernetes. But it might go the same way as Ksonnet.

[1] https://github.com/cruise-automation/isopod

Standard Go templating seems really lacking if you come from something like Jinja. Even with libraries like https://masterminds.github.io/sprig/ (used e.g. for Helm templating) it feels hard to use.

Eleven, you'd be surprised what go template libs are out there like sprig. https://masterminds.github.io/sprig/

If you use Go templates be sure to use Sprig as well to get more usable functions.

I'd highly recommend tossing in the sprig library and depending on how you break up your templates, maybe creating a custom "include" helper instead of using the built in define/template helpers. The advantage of this is that if each template is capable of rendering itself independently, you can potentially render all of your templates in parallel.

The discoverability of golang templates is terrible, IMHO, since it's missing a "dir(locals())" equivalent and every execution environment gets to make its own rules about what pipelines/functions are exposed

Look at helm as an example: https://helm.sh/docs/chart_template_guide/function_list/ is some of them, https://helm.sh/docs/chart_template_guide/accessing_files/#p... are some others, but they also glued in some version of https://masterminds.github.io/sprig/ So, short of (a) knowing that's the case (b) having 3+ bookmarks in your favorite browser to refer to those reference pages, how would anyone know what pipelines are available?

Separately, I dooooo nooooooot understand why every joker has to invent their own new thing when we have like 50 or so templating languages already. Golang may be an outlier in that competition due to the Google Promotion Packet Effect(tm) but how they came up with `{{ range }}{{ end }}` as sane syntax is some true facepalm, to say nothing of the same landmine that ansible stepped on by not switching jinja2's default characters: `{{` is not _yaml safe_

You mentioned something about PHP. We also already have a templating language in the standard library that can be extended (commonly done with sprig).

Plopjs looks interesting and is probably not too hard to write for yourself in Go. You could add something like sprig for some useful template functions.

Not at all. It was "write a helm template using the following imaginary values in a values file". In 30 minutes, I was able to google the Kubernetes api and the sprig functions for templating, complete the assignment, fix a stupid typo the unit test caught, and spend 5 minutes trying to think of any corner cases that hidden unit tests might catch (I don't know if there were any hidden unit tests). The goal of this take-home assessment was to prove that you are not wasting an engineer's time when they call you, not to prove that you should be hired.

Support sprig in Template

They may refer to the definitive shortage of built-in functions. The template engine itself only provides the bare minimum. That's usually not a problem because of template function libraries like https://github.com/Masterminds/sprig