starlark-go VS tanka

Starlark in go https://github.com/google/starlark-go is a great way to combine the best of both, the ease of use of Python and the simplicity of go.

I have been building a platform for deploying internal web applications using this approach https://github.com/claceio/clace. Use Starlark to configure the application, the platform itself is built in go.

The big unknown is your task definition: what does user-defined logic look like? If you're expecting go code, that's gonna need some cleverness because of the compiled nature of it. There's a node runtime implemented in go if you want to provide sandboxed javascript (check the source of k6.io, it's the main one I know that uses it). If you want to provide building blocks and let them compose them, starlark might be a good choice.

Another one of those (with broader language support) is the Starlark language, which has a Go implementation: https://github.com/google/starlark-go

Every config format gets as complex to be touring complete in the end. We had similar problems and eventually got rid of that complexity and switched to starlark (the bazel config language), was a huge benefit for the tools. https://github.com/google/starlark-go "Starlark is a dialect of Python intended for use as a configuration language. Like Python, it is an untyped dynamic language with high-level data types, first-class functions with lexical scope, and garbage collection."

Direct link to the Go implementation of Starlark: https://github.com/google/starlark-go

For a Python-like syntax, https://github.com/google/starlark-go is the language used in Babel. It's very mature, but since it is used in a massive mature project with a specific purpose, it doesn't move fast or drift from the spec of its Java-based sibling. It doesn't have exception try except blocks or some other features you might expect, but for short extension logic, it might be exactly what you want with the stability you can depend upon.

Context: https://github.com/google/starlark-go/blob/cfacd890221418a2dc2c736f7b5e3476c38709b1/starlark/int_posix64.go

Thus envd is more like Dockerfile, while it uses a simplified python dialect starlark https://github.com/google/starlark-go as the build language.

Use Go (mostly for starlark-go)

I would recommend implementing a similar API to Grafana Tanka: https://tanka.dev

When you "synthesise", the returned value should be an array or an object.

1. If it's an object, check if it has an `apiVersion` and `kind` key. If it does, yield that as a kubernetes object and do not recurse.

Maybe you'd like jsonnet: https://jsonnet.org/

I find it particularly useful for configurations that often have repeated boilerplate, like ansible playbooks or deploying a bunch of "similar-but" services to kubernetes (with https://tanka.dev).

Dhall is also quite interesting, with some tradeoffs: https://dhall-lang.org/

A few years ago I did a small comparison by re-implementing one of my simpler ansible playbooks: https://github.com/retzkek/ansible-dhall-jsonnet

- validation is often impractical (at least identifying exactly where the error is… I’m looking at you Helm!)

Unrelated to OP, but you can leverage Tanka to extend helm charts with functionality not provided by upstream.

https://tanka.dev/

Although jsonette might be considered more complex Tanka is a great alternative for k8s config management.

At Grafana Labs we're using jsonnet at scale, while being a powerful functional language it is also excellent for rendering JSON/YAML config. We have developed Tanka[0] to work with Kubernetes, for other purposes I can recommend this course[1] (authored by me).

[0] https://tanka.dev/

[1] https://jsonnet-libs.github.io/jsonnet-training-course/

If you're hitting the limits of Kustomize, maybe look at Tanka as well.

Yes, try Tanka.

yes. basically. and this is a path that multiple people are trying to solve. e.g. AWS CDK8s, https://tanka.dev/, etc

Compose would be awesome.

http://tanka.dev

(Note I work for Grafana Labs who fund Tanka and use it for all production config)