example of ruby code to help drive terraform apply

terraform_apply.rb

#!/usr/bin/ruby
# terraform/lib/terraform.rb

require_relative 'aws'

$terraform_dir = "/opt/terraform"
$terraform_templates = "/opt/terraform_templates"
$terraform_bin = "#{$terraform_dir}/terraform"

def set_terraform_variables(network_zone, instance_name, cluster_name)

  key_name = "rundeck-stage"
  key_path = "/var/lib/rundeck/.ssh/id_rsa"
  aws_region = ENV['RD_OPTION_REGION']
  aws_access_key = ENV['AWS_ACCESS_KEY']
  aws_secret_key = ENV['AWS_SECRET_KEY']
  instance_type = ENV['RD_OPTION_INSTANCE_SIZE']
  subnet_id = get_subnet_id(aws_region, network_zone)
  image_id= ENV['RD_OPTION_AMI_ID']
  user_data = create_user_data(instance_name, cluster_name)

  variables =
    "-var instance_name=#{instance_name} " +
    "-var key_name=#{key_name} " +
    "-var key_path=#{key_path} " +
    "-var aws_region=#{aws_region} " +
    "-var aws_access_key=#{aws_access_key} " +
    "-var aws_secret_key=#{aws_secret_key} " +
    "-var instance_type=#{instance_type} " +
    "-var subnet_id=#{subnet_id} " +
    "-var image_id=#{image_id} " +
    "-var user_data=#{user_data} "

    return variables
end

def terraform_apply(network_zone, instance_name, instance_volume_option, cluster_name)

  terraform_cluster_state_file = "/var/lib/rundeck/data/terraform_#{cluster_name}.tfstate"
  terraform_variables = set_terraform_variables(network_zone, instance_name, cluster_name)
  terraform_cmd = "#{$terraform_bin} apply -no-color --state=#{terraform_cluster_state_file} #{terraform_variables} #{$terraform_templates}"

  puts "****"
  puts "..Launching instance: #{instance_name}"
  puts "..Executing #{$terraform_bin} to build #{instance_name}"
  instance_id = ""
  instance_ip_address = ""
  IO.popen(terraform_cmd) do |io|
    while (line = io.gets) do
      if line =~ /instance_id/
        instance_id = line.split("=")[1].strip
      elsif line =~ /instance_ip_address/
        instance_ip_address = line.split("=")[1].strip
      end
      puts "...." + line
    end
  end

  return instance_id, instance_ip_address
end