Comment 8 for bug 1384259

Looking at the logs pasted into the bug though, cloud-init seems to have finished before Juju starts running its scripts:

...
Cloud-init v. 0.7.5 running 'modules:config' at Wed, 22 Oct 2014 11:56:48 +0000. Up 30.67 seconds.
Generating locales...
  en_US.UTF-8... up-to-date
Generation complete.
Cloud-init v. 0.7.5 running 'modules:final' at Wed, 22 Oct 2014 11:56:54 +0000. Up 36.57 seconds.
+ install -D -m 644 /dev/null /var/lib/juju/nonce.txt
+ printf %s\n user-admin:bootstrap
Cloud-init v. 0.7.5 finished at Wed, 22 Oct 2014 11:56:55 +0000.
DataSourceOpenStack [net,ver=2]. Up 37.66 seconds
Ign http://security.ubuntu.com trusty-security InRelease
Get:1 http://security.ubuntu.com trusty-security Release.gpg [933 B]
...