Generate Terraform config for CoreOS AMIs

coreos_ami.tf.json

{
  "variable": {
    "coreos_stable_amis": {
      "default": [
        {
          "eu-central-1": "ami-f0e8f09c"
        },
        {
          "ap-northeast-1": "ami-a93802c7"
        },
        {
          "us-gov-west-1": "ami-46e05c27"
        },
        {
          "sa-east-1": "ami-6c1a9a00"
        },
        {
          "ap-southeast-2": "ami-d0a783b3"
        },
        {
          "ap-southeast-1": "ami-4a65aa29"
        },
        {
          "us-east-1": "ami-dfb699b5"
        },
        {
          "us-west-2": "ami-abc82ecb"
        },
        {
          "us-west-1": "ami-4d2d5b2d"
        },
        {
          "eu-west-1": "ami-1461d767"
        }
      ]
    }
  },
  "output": {
    "coreos_stable_ami": {
      "value": "${lookup(var.coreos_stable_amis, var.region)}"
    }
  }
}

coreos_ami_tf.rb

#!/usr/bin/env ruby
#
# Update CoreOS AMIs

require 'open-uri'
require 'json'

# source URL
coreos_stable_url = "https://coreos.com/dist/aws/aws-stable.json"

# target file
module_file = "contentful_amis/coreos.tf.json"
coreos_amis_tf = File.expand_path(File.dirname(__FILE__) + "/../" + module_file)

begin
  coreos_stable_json = JSON.parse(open(coreos_stable_url) { |f| f.read })
rescue => e
  puts e.msg
  exit 1
end

per_region_hvm = coreos_stable_json.reject { |k,v| k == "release_info" }
                  .map { |k,v| { k => v["hvm"] } }

tf_config = {
  "variable" => {
    "coreos_stable_amis" => {
      "default" => per_region_hvm
    }
  },
  "output" => {
    "coreos_stable_ami" => {
      "value" => "${lookup(var.coreos_stable_amis, var.region)}"
    }
  }
}

File.open(coreos_amis_tf, 'w') do |f|
  f.write JSON.pretty_generate tf_config
end