helm-deno

helm-deno allows write helm charts with JavaScript and TypeScript

️Project status: Alpha️

Project currently in its early stage. Breaking changes are to be expected. Please read changelog before upgrade.

• Known bugs
• Missing features
• Expected breaking changes

Features

• Write charts in JavaScript and TypeScript
• Easy to extend with deno modules
• Can be used with helm-secrets, helm-diff and helm-push

What deno is?

Deno is a simple, modern and secure runtime for JavaScript and TypeScript that uses V8 and is built in Rust. Learn more on Deno official website.

Installation

helm plugin install https://github.com/CSSSR/helm-deno

There is no need to install Deno, it will be installed automatically.

Getting started

helm deno create chart-name # TODO: currently does not work (issue #10)

It will create a directory structure that looks something like this:

chart-name/
├── .helmignore     # Contains patterns to ignore when packaging Helm charts.
├── Chart.yaml      # Information about your chart
├── values.yaml     # The default values for your templates
└── deno-templates/ # The template files
    ├── mod.ts
    └── resources/
        ├── deployment.ts
        ├── service.ts
        └── ingress.ts

Render templates and print the result

helm deno template my-release chart-name/

Benefits

We have written this plugin because we wasn't happy with default helm's templates system: Go templates. There is some of things which wasn't possible with it or was too complex to deal with.

Working with data structures, not templates. Programming languages are much more suitable for working with data such as kubernetes objects. And using functions instead of define and template is so much simpler.

Modules. Deno has a big set of standard and third-party modules. Publishing your own modules is as easy as pushing file to git repository or serving static files.

Type System and static analysis. Types for your chart values is a good documentaion which is always up-to-date. You are also safe from errors like typos and using variables that do not exist.

Ability to work with file system and network. You can replace kubernetes operators or helm plugins with just a function. For example, decode a sops-encrypted file or fetch secrets from Hashicorp Vault.

Current limitations

• Does not support passing options via equal sign --values=values-file.yaml
• Require strict order of command-line arguments: helm deno <secrets> <diff> upgrade/template/install [RELEASE] [CHART] <flags>
• Does not support --reuse-values
• Slower that go templates
• Possible have bugs: doesn't have much tests yet
• Was not tested on Windows but it should probably works