instance method generate_local_secret

# File railties/lib/rails/application/configuration.rb, line 709
        def generate_local_secret
          key_file = root.join("tmp/local_secret.txt")

          random_key = begin
            File.binread(key_file)
          rescue SystemCallError
            nil
          end

          if random_key.blank?
            random_key = SecureRandom.hex(64)
            FileUtils.mkdir_p(key_file.dirname)
            File.binwrite(key_file, random_key, perm: 0o600)
          end

          unless Gem.win_platform?
            begin
              File.chmod(0o600, key_file) unless (File.stat(key_file).mode & 0o077).zero?
            rescue SystemCallError
            end
          end

          random_key
        end