[chef] Ohai attributes in Default attributes

[Tom < >]

Ohai,

I'm using chef-solo and I am loading some attributes into ohai - specifcally some custom ec2 data generated from tags and userdata.

I'd like to be able to set some of the default attributes in my cookbook to the values in Ohai, but when I load a chef-solo run I am receiving the following error:

[2013-03-18T14:45:36+00:00] FATAL: Stacktrace dumped to /var/cache/chef-solo/chef-stacktrace.out

and it points to the cookbook attribute:

 83>> default['jockey']['cluster_name']                         = node['ec2']['instance']['Env'].downcase

I presume this is happening because Ohai has not been populated with my custom data by the time default attributes have been processed in the deep merge.

Is there a better/different way I should be loading these attributes?

Thanks for any help.

Tom