ThorでAWSごにょごにょする時にいつも書いてる気がするやつ

thor_aws.rb

require "thor"
require "aws-sdk-resources"

class OrenoAwsTool < Thor
  class_option :profile,
    desc:    "Load credentials by profile name from shared credentials file (~/.aws/credentials).",
    aliases: [:p]

  class_option :access_key_id,
    desc:    "AWS access key id.",
    aliases: [:k]

  class_option :secret_access_key,
    desc:    "AWS secret access key.",
    aliases: [:s]

  class_option :region,
    desc:    "AWS region.",
    aliases: [:r]

  # 中略

  private

  def aws_configuration
    hash = {}

    [:profile, :access_key_id, :secret_access_key, :region].each do |option|
      hash.update(option => options[option]) if options[option]
    end

    hash.update(region: own_region) if hash[:region].nil? && ENV["AWS_REGION"].nil?
    hash
  end

  def own_region
    @own_region ||= begin
      require "net/http"

      timeout 3 do
        Net::HTTP.get("169.254.169.254", "/latest/meta-data/placement/availability-zone").chop
      end
    rescue
      nil
    end
  end

  def ec2
    @ec2 ||= Aws::EC2::Resource.new aws_configuration
  end
end