# File lib/openshift-origin-node/model/unix_user.rb, line 318
    def add_env_var(key, value, prefix_cloud_name = false, &blk)
      env_dir = File.join(@homedir,'.env/')
      if prefix_cloud_name
        # BZ 874594
        if @config.get("CLOUD_NAME")
          Syslog.alert "Setting CLOUD_NAME in #{OpenShift::Config::NODE_CONF_FILE} has no effect."
        end
        key = "OPENSHIFT_#{key}"
      end
      filename = File.join(env_dir, key)
      File.open(filename,
          File::WRONLY|File::TRUNC|File::CREAT) do |file|
            file.write "export #{key}='#{value}'"
        end

      if block_given?
        blk.call(value)
      end
    end