terraform-provider-ct allows Terraform to validate a Butane config or Container Linux Config and transpile to an Ignition config for machine consumption.

Usage

Configure the config transpiler provider (e.g. providers.tf).

provider "ct" {}

terraform {
  required_providers {
    ct = {
      source  = "poseidon/ct"
      version = "0.9.2"
    }
  }
}

Define a Butane config (for Fedora CoreOS) or Container Linux Config (for Flatcar Linux):

# Butane config
---
variant: fcos
version: 1.4.0
passwd:
  users:
    - name: core
      ssh_authorized_keys:
        - ssh-key foo

# Container Linux Config
---
passwd:
  users:
    - name: core
      ssh_authorized_keys:
        - ssh-key foo

Define a ct_config data source and render for machine consumption.

data "ct_config" "worker" {
  content      = file("worker.yaml")
  strict       = true
  pretty_print = false

  snippets = [
    file("units.yaml"),
    file("storage.yaml"),
  ]
}

resource "aws_instance" "worker" {
  user_data = data.ct_config.worker.rendered
}

Run terraform init to ensure plugin version requirements are met.

$ terraform init

Requirements

Terraform v0.13+ installed

Versions

Butane configs contain a version that is associated with an Ignition format version. For example, a Butane config with version: 1.0.0 would produce an Ignition config with version 3.0.0, across future releases.

Container Linux Configs render a fixed Ignition version, depending on the terraform-provider-ct release, so updating alters the rendered Ignition version.

terraform-provider-ct	CLC to Ignition	Butane to Ignition
0.9.x	Renders 2.3.0	Butane (1.0, 1.1, 1.2, 1.3, 1.4) -> Ignition (3.0, 3.1, 3.2, 3.2, 3.3)
0.8.x	Renders 2.3.0	Butane (1.0, 1.1, 1.2, 1.3) -> Ignition (3.0, 3.1, 3.2, 3.2)
0.7.x	Renders 2.3.0	Butane (1.0, 1.1, 1.2) -> Ignition (3.0, 3.1, 3.2)
0.6.x	Renders 2.3.0	Butane (1.0, 1.1) -> Ignition (3.0, 3.1)
0.5.x	Renders 2.2.0	Butane 1.0.0 -> Ignition 3.0.0
0.4.x	Renders 2.2.0	Butane 1.0.0 -> Ignition 3.0.0
0.3.x	Renders 2.2.0	NA
0.2.x	Renders 2.0.0	NA

Notes:

Butane config snippets must match the version set in the content. Version skew among snippets is not supported.

Development

Binary

To develop the provider plugin locally, build an executable with Go v1.16+.

make