Open Stack

We're very much looking forward to the new "portable configuration
drive" functionality and would like to provide feedback. If this is not
the best forum, please point me to it.

The blueprint
is: https://blueprints.launchpad.net/nova/+spec/configuration-drive
We reviewed the initial work
in: https://github.com/ChristopherMacGown/nova/commit/47c041a642ff32085b3140475d7a2a62dcb62c1a

Feedback:

1. It is not always obvious how to enumerate attached devices and the
document doesn't explicitly cover how we'd determine which attached
device represents the configuration volume. Specifically consider
Windows as well.

2. Will the configuration drive be available at boot time on a new
instance? Or does it appear "later" (that would be bad)?

3. How does one send the configuration drive content?  What is the API
call where we provide the configuration information and what is the
expected format?

4. It looks like the configuration content is placed into a config.json
file, is this correct? Is that a blob passed through the API? Does it
have to be json or is that just a convention? What is the max size?

5. What are the permissions required to access the configuration drive?
Would be ideal for the content to be root/administrator accessible only
(because it may contain credentials). Can this be influenced via the API?

6. Is this device going to be read-only?

7. We need to be able to change the configuration content when
stopping&starting instances, will this be possible?

8. There is a related spec: 'instance-transport'. Is that still
relevant? Or superseded by the configuration drive?

9. Will the configuration drive contain any metadata? E.g. IP addresses,
names of available volumes, instance ID, etc.

Thanks much!
Thorsten - CTO RightScale