[chef] Using Chef to Configue Autoscaled EC2 Instances

[< >]

Hi all, I'd like to get some feedback on how people are doing this now. It
seems that since .10, the preferred way of starting Amazon EC2 instances is 
via
the 'knife ec2 server create' command, while the 'knife ec2 instance data' and
chef preinstalled AMIs are deprecated. That's all fine and good for manually
launching instances, but what about autoscaling? When a node comes up for
autoscalling, I want it to update and configure itself according to its 
role(s)
and environment. With the instance data method of doing thing deprecated,
what's the alternative (aside from having a custom baked AMI that I need to
manually update as is the normal way of doing this without chef)? If there is
no alternative, and I have to use the deprecated method which would mean using
'knife ec2 instance data' to wire into the autoscaling group as UserData. When
using this method how would I specify the environment that the server should 
be
run as too? I don't see anyway to do this using the instance data. Running 
some
command outside the server after the server it is started to set the
environment is not an option as we won't know when a new server has been spun
up (controlled by Amazon). 

I'm interested in what other people have found to be best practice for this
scenario and any advice, tips or tricks that have been learned while trying to
work with chef and autoscaled EC2 instances. 

Thanks for your thoughts!