How does tensorflow ignore undefined flags

I solved my problem by defining these flags in tensorflow model: my_tf_model.py.

tf.app.flags.DEFINE_string('bind', '', 'Server address')
tf.app.flags.DEFINE_integer('timeout', 30, 'Server timeout')

And then changed my gunicorn command line to use double dash style command line:

gunicorn --bind 0.0.0.0:5000 --timeout 30 wsgi:app

But I think there should be some other way rather than this hack to resolve the globally-used flags.