Hi Tran,
Google Groups isn't the place to post specific technical issues, as this forum is meant more for general discussion of the platform and services.
If you would like help with a technical issue, you should post to stackoverflow [1] or serverfault [2].
If you believe you've identified and can reproduce an issue with the platform itself (behaviour is different from documentation or error occurs during normal use), then you should proceed to open a public issue tracker [3] issue with enough detail to reproduce the issue on our side, or if possible, an attached app that can be used to directly observe the behaviour.
Your issue seems to be related to how you've configured bitnami or whether you're using the right metadata flags. At any rate, peol eon stackoverflow or serverfault will be much more likely to be able to help you debug. Another thing that comes to mind is perhaps you can SSH into the instance and inspect bitnami logs which may have more information? At any rate, I can't comment authoritatively on this, and as said, this isn't the forum to post specific technical 1-on-1 support issues.
If you would like to open a thread in this forum discussing the platform or services in more broad terms, starting a discussion that would be useful for other users to join in to, feel free to do so.
Have a great day!