How do detect that cloud-init completed initialization

Question

I am configuring an OpenStack box using cloud-init/cloud-config. I intend to wait until it is fully configured before I start using it.

This is not all that hard to do using some marker file or detecting if the cloud-init process is still running, though it seems quite cumbersome to do that in every cloud-init script. Is there some recommended way? Natively supported by cloud-init, ideally?

Oliver Gondža Oliver Gondža · Accepted Answer · 2016-02-20T07:02:54

As @flyxiao pointed out, cloud-init put status information into a dedicated directory on a filesystem: /run/cloud-init/ (preferred over /var/lib/cloud/data/ as it is guaranteed to describe last init process). status.json contains detailed about all init phases and result.json denotes the whole init is completed. The project documentation suggest a python script to detect cloud-init completion:

 fin = "/run/cloud-init/result.json"
 if os.path.exists(fin):

   ret = json.load(open(fin, "r"))

   if len(ret['v1']['errors']):

     print "Finished with errors:" + "\n".join(ret['v1']['errors'])

   else:

     print "Finished no errors"

 else:

   print "Not Finished"

How do detect that cloud-init completed initialization

5 Answers