YAML2Jsonnet: Switch configuration languages

Converts YAML into Jsonnet (specifically targetting YAML for Kubernetes)

Suppose that you have some YAML that you use for Kubernetes (either hand-written or output by Helm. Now you'd like to use Jsonnet instead, for its fancier templating capabilities. This is a pain, because while YAML->JSON converters are easy to find, they produce ugly-looking (but valid!) Jsonnet.

YAML2Jsonnet makes the conversion a little easier: it transforms the YAML into slightly prettier Jsonnet, preserving comments along the way.

Example

A trivial YAML document:

---
# simple example
- hello: world
  one: 1

Convert it to Jsonnet:

$ yaml2jsonnet trivial.yaml | jsonnetfmt - -o trivial.jsonnet

(Note that we run the output of yaml2jsonnet through the jsonnet formatter jsonnetfmt. This is strongly recommended, since the raw output of yaml2jsonnet is quite ugly.)

The result:

[
  // simple example
  {
    hello: 'world',
    one: 1,
  },
]

Installing

Yaml2Jsonnet expects Python 3.6 or above.

pip install yaml2jsonnet

Or, as this is meant as a stand-alone tool, you may prefer

pipx install yaml2jsonnet

Development

• Install Poetry
• Install Pre-commit
• Run poetry install to install dependencies
• Run poetry run python -m yaml2jsonnet /path/to/yaml to convert a file
• Probably, run jsonnetfmt on the output, since the only whitespace I provide is newlines