Open Stack

Hi Dave,

When we try to boot our VM we mount the label config-2 and access its contents,
But it is seen that in some customer deployments, the label has different name (ex: CONFIG-2), hence our code breaks.
We want to make sure, if  it is always config-2 ?? on what basis it can change ?? or is it set at some location in Openstack config files ??

Thanks
Bhaskar




From: Dave Walker [mailto:email at daviey.com]
Sent: Monday, April 27, 2015 2:35 PM
To: Bhaskar Rao
Cc: openstack-qa at lists.openstack.org; openstack at lists.openstack.org
Subject: Re: [Openstack] config drive on opentack label query


On 27 Apr 2015 09:32, "Bhaskar Rao" <bhaskar.rao at citrix.com<mailto:bhaskar.rao at citrix.com>> wrote:
>
> Hi All,
>
>
>
> With help of user data files, we can provide instance specific details (like IP address, Gateway etc.) to VM booting in OpenStack environment.
>
> This user data file gets attached with VM as part of specific label for example config-2.
>
>
>
> We want to know how this labeling mechanism works? Who decides to give name ‘config-2’ to use for supplied info?
>
> Is there any possibility that instead of ‘config-2’, it can use another name e.g. ‘config-x’?
>
>
>
> Thanks,
>
> Bhaskar
>

Hi,

The name is specifically crafted for config-drive version 2. The reference consumer of this is cloud-init (on linux), but other projects such as cloudbase-init (on windows), also consume this standard.  This standard was originally written for OpenStack.

Version 2 was created due to short fallings with the original spec, and both of these consumers specifically match on the device being named 'config-v2' to avoid miss-parsing the wrong device. Therefore changing the name in the hard coded portion of nova would break the consumers.

To flip the topic slightly, why would you want to use a different named device?  What are you trying to do?

--
Kind Regards,
Dave Walker
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