Failed to submit the online prediction request about cloudml-samples

[DerekGrant]

I found the reason for this problem that dues to the mistake of the model's export path.
When exploring the model, it should be saved to:

Model exported to:  local-training-output/keras_export/1553709223

but in fact, may due to the tf version reason, it just exported to

Model exported to:  local-training-output/keras_export/

So when you run

SAVED_MODEL_PATH = KERAS_EXPORT_DIRS[-1]

SAVED_MODEL_PATH is expected as "local-training-output/keras_export/1553709223";
but in fact, you will get "local-training-output/keras_export/variables"

Hence, when you save your model, it will tell you there isn't a "saved_model.pb" in "variables".
I just copy a pb file to "variables" to solve it.

But later, when you want to predict, it will load model from "variables", where doesn't have any parameters of the model, so you will fail.