[CNCF LFX Proposal] Flatcar Container Linux: Cloud-Init to Butane YAML config transpiler

### CNCF Project

Flatcar Container Linux

### Term

2026 Term 3 (Sep-Nov)

### Program Name

Cloud-Init to Butane YAML config transpiler

### Program Description

This is a software development project (Go language) for transpiling from one well-defined YAML format (cloud-config) into another (butane). The project aims to implement the minimum functionality necessary to support ClusterAPI worker node provisioning. This limits the transpiler's scope to support only basic Butane features (users, groups, certificates, files, systemd units, etc.).

While the project itself is well scoped and both formats the transpiler is supposed to work with are well defined, it exists in a complex environment of Linux OS operations and OS provisioning.

Mentors are aware and will give support and guidance, in particular with:
- scope, goals, and non-goals
- on-boarding, development loop, and local testing
- integration with Flatcar and ClusterAPI

### Technologies

Go, YAML, ClusterAPI, Linux Based OS

### Skills same as Technologies?

- [x] Yes, the required skills are the same as the technologies listed above.

### Required/Desirable Skills

_No response_

### Mentors

Mathieu Tortuyaux | @tormath1 | mathieu.tortuyaux@gmail.com | TortueMat
Thilo Fromm | @t-lo | thilo.fromm.work@gmail.com | t-lo
Michael McCune | @elmiko | msm@opbstudios.com | elmiko

### Upstream Issue URL

https://github.com/flatcar/Flatcar/issues/2226

### Application Prerequisites

- [x] Resume
- [x] Cover Letter
- [ ] School Enrollment Verification
- [ ] Participation Permission from school or employer
- [ ] Coding Challenge
- [ ] Custom Prerequisite (fill in details below)

### Coding Challenge URL

_No response_

### Custom Prerequisite Name

_No response_

### Custom Prerequisite Description

_No response_

### Custom Prerequisite — File Upload

- [ ] Yes — completion of this task requires the mentee to submit a file.

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**LFX program:** [CNCF - Flatcar Container Linux: Cloud-Init to Butane YAML config transpiler (2026 Term 3)](https://mentorship.lfx.linuxfoundation.org/project/5245ead5-180e-4117-92cd-1d3ec075ed97)

Start with the upstream Flatcar issue #2226 and read the cloud-config and Butane format requirements for ClusterAPI worker-node provisioning. Use the stated minimum scope—users, groups, certificates, files, and systemd units—to define acceptance cases; done means a Go transpiler handles those cases and is locally tested with mentor guidance.

Written by the indexing model from the issue text.