Write secret key file and then reference it

gistfile1.rb

get_file = ruby_block "get_file" do
  block do
    conn = Some::Remote.new("param")
    remoteFile = conn.get("/path/to/file")
    localFile = File.open("/tmp/test_secret_key",'w')
    localFile.write(remoteFile.contents)
  end
  not_if { ::File.exists?("/tmp/test_secret_key") }
  action :nothing
end
get_file.run_action(:create)

secret_key = Chef::EncryptedDataBagItem.load_secret("/tmp/test_secret_key")

# Fails: invalid zero length secret in "/tmp/test_secret_key"