openstack team mailing list archive

[Justin Santa Barbara <justin@xxxxxxxxxxxx>]

Is there a (de-facto) standard for image metadata/properties?  I'd like to
be able to able to launch e.g. the Debian Squeeze image provided by the
cloud.  This is particularly important for clouds that don't allow image
upload, but likely this will remain useful because different clouds will
have different tweaks needed (e.g installing the right drivers based on the
hypervisor).

I could try "smart"-parsing the names, but it seems like metadata is the
right way to do this, and I see no reason why any cloud would gain any
advantage from not adopting a common convention.  I know some clouds have
started implementing their own approaches, but I don't believe anyone is
locked into anything.

In the interest of efficiency, I'm going to make a proposal for people to
attack:

3 main pieces of metadata: os:distro, os:version_major, os:version_minor

I'm thinking of the os prefix as standing for OpenStack, not Operating
System.  I'd like to 'reserve' the os prefix for 'agreed' prefixes.  Maybe
this should be openstack.org:distro ?

os:distro would be the primary domain name of the distro, i.e. redhat.com,
ubuntu.com, debian.org, centos.org etc

os:version_major would be the major version of the release:
debian.org: 6.0, 5.0, 4.0, 3.1, 3.0, 2.2, 2.1, 2.0
ubuntu.com: 10.04, 10.10, 11.04, 11.10, 12.04

Numbers seem more machine-friendly than codenames - 6.0, not squeeze -
humans will probably use the image names.

os:version_minor would be the minor version of the release (because it's a
minor revision, hopefully we shouldn't normally have to check this,
although we might want to select the latest always).

So os:distro="debian.org" os:version_major "6.0" os:version_minor "3" would
be an image of debian 6.0.3.

Questions / ideas for other properties:

   - Some clouds will automatically respin images e.g. weekly with the
   latest updates.  This could also be exposed through metadata.
    os:updated_through= "20120301" ?
   - Some clouds will offer only bare images, some will provide a variety
   e.g. bare, LAMP, Hadoop, etc.  Should we use the native package names to
   indicate additional packages?  e.g. os:packages="apache2,mysql,php5" ?

As a (programmatic) consumer of these images, my wishlist:

   - A cloud will have to put on whatever drivers / agents they need to,
   but ideally these should otherwise be clean images, with minimal deviation
   from the stock install.  (Or 'clean' images should be available alongside
   other images)  It would be great if I could be launch a 'clean' image on
   any OpenStack cloud and have it behave more or less the same; I shouldn't
   have to second guess any additional tweaks.
   - I would like to be able to launch the clean image and install updates
   myself, in case I don't want a particular update.  Providing a fast apt
   cache is much better than providing respun images, for my use-case.  I
   would be great if old images stuck around, therefore!


Justin

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Justin Santa Barbara
Founder, FathomDB