[openstack-dev] [kolla] on Dockerfile patterns

Vishvananda Ishaya vishvananda at gmail.com
Wed Oct 15 14:52:56 UTC 2014


On Oct 14, 2014, at 1:21 PM, Lars Kellogg-Stedman <lars at redhat.com> wrote:

> On Tue, Oct 14, 2014 at 04:06:22PM -0400, Jay Pipes wrote:
>> I understand that general feeling, but system administration tasks like
>> debugging networking issues or determining and grepping log file locations
>> or diagnosing packaging issues for OpenStack services or performing database
>> logfile maintenance and backups don't just go away because you're using
>> containers, right?
> 
> They don't go away, but they're not necessarily things that you would
> do inside your container.
> 
> Any state (e.g., database tables) that has a lifetime different from
> that of your container should be stored outside of the container
> proper.  In docker, this would be a "volume" (in a cloud environment,
> this would be something like EBS or a Cinder volume).
> 
> Ideally, your container-optimized applications logs to stdout/stderr.
> If you have multiple processes, they each run in a separate container.
> 
> Backups take advantage of the data volumes you've associated with your
> container.  E.g., spawning a new container using the docker
> "--volumes-from" option to access that data for backup purposes.
> 
> If you really need to get inside a container for diagnostic purposes,
> then you use something like "nsenter", "nsinit", or the forthcoming
> "docker exec”.

“something like” isn’t good enough here. There must be a standard way
to do this stuff or people will continue to build fat containers with
all of their pet tools inside. This means containers will just be
another incarnation of virtualization.

Vish

> 
> 
>> they very much seem to be developed from the point of view of application
>> developers, and not so much from the point of view of operators who need to
>> maintain and support those applications.
> 
> I think it's entirely accurate to say that they are
> application-centric, much like services such as Heroku, OpenShift,
> etc.
> 
> -- 
> Lars Kellogg-Stedman <lars at redhat.com> | larsks @ {freenode,twitter,github}
> Cloud Engineering / OpenStack          | http://blog.oddbit.com/
> 
> _______________________________________________
> OpenStack-dev mailing list
> OpenStack-dev at lists.openstack.org
> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 455 bytes
Desc: Message signed with OpenPGP using GPGMail
URL: <http://lists.openstack.org/pipermail/openstack-dev/attachments/20141015/7025d2bd/attachment.pgp>


More information about the OpenStack-dev mailing list