gpg sample wrapper.rb

class GpgWrapper
  class GpgNotInstalled < StandardError; end
  class CanNotFindPgpKey < StandardError; end

  attr_reader :file_to_encrypt, :tmp_dir, :pgp_key, :email

  def initialize(file_content, for_what = "customer")
    check_gpg
    load_config(for_what)
    random_filename = "#{String.random}_#{Time.now.to_i}.xml"
    @file_to_encrypt = path_for(random_filename)
    File.open(file_to_encrypt, "w") do |f|
      f.write(file_content)
    end
  end

  def encrypt
    import_key
    output_file = path_for("#{String.random}_#{Time.now.to_i}.encrypted")
    `#{GpgWrapper.command} -r #{email} -q --no-verbose --always-trust  -a -o #{output_file} --yes -e #{file_to_encrypt}`
    File.read(output_file)
  end

  def import_key
    raise CanNotFindPgpKey unless pgp_key
    `#{GpgWrapper.command} --import #{pgp_key}`
  end

  def self.command
    '/usr/bin/env gpg'
  end

  private

  def path_for(filename)
    @tmp_dir ||= Dir.tmpdir
    File.join(tmp_dir, filename)
  end

  def check_gpg
    raise GpgNotInstalled.new("Please install gpg ('brew install gnupg')") unless `#{GpgWrapper.command} --version`.present?
  end

  def load_config(for_what)
    @pgp_key = File.join(Rails.root, PistachioConf.config.third_party_keys.send(:[], for_what.to_s)["key_path"])
    @email = PistachioConf.config.third_party_keys.send(:[], for_what.to_s)["email"]
  end
end