terraform-provider-ct

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 = "0.10.0"
    }
  }
}

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 are converted to the current (according to this provider) stable Ignition config and merged together. For example, a Butane Config with version: 1.2.0 would produce an Ignition config with version v3.3.0. This relies on Ignition's forward compatibility.

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

Before terraform-provider-ct v0.10.0, Butane configs contained a version that was 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.

terraform-provider-ct	CLC to Ignition	Butane to Ignition
0.10.x	Renders 2.3.0	Butane (1.0, 1.1, 1.2, 1.3, 1.4) -> Ignition 3.3
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

Development

Binary

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

make