[Openshift Commons Image Builders SIG] Image Building and Terminology

[Brent Baude]

Comments inline...

On Tue, 2016-05-24 at 09:49 -0400, Scott McCarty wrote:
> All,
>      Last week at the container interlock, one of you (sorry, can't
> remember who, maybe Diogones?) was talking about the Middleware team
> building "base images" which contained VMs.  As a follow up, I wanted
> to understand what was meant by that. I think one of two things could
> be happening, but I didn't want to rat hole the presentation.
> 
> 1. We are not using the word base image correctly?
> 2. We are planning on releasing Middleware base images?
> 3. More complicated. Relies on RHEL, but squashed (still has a base
> image of RHEL)
> 
> If #1, check out this article [1] which I did a ton of homework on
> and references Docker's documentation, which defines a base image as
> an image with no parent layer.
> 
That is the definition I also tend to favor.  I also tend to only
associate base images with distributions/OS's.

> If #2, I think the RHEL team and the middleware team should talk. I
> believe we really need to make sure all software in Red Hat products
> rely on the RHEL "base image" and should probably NOT be creating
> their own base images.
> 

Agree completely.  However, if all RH middleware images contained a
significant, similar set of additional packages/configuration, it might
make sense to have a RH middleware layered image based on the official
base-image.  This theoretically could make life easier for folks.

> If #3, I think we should discuss what we message to the world
> (especially customers) about how these are built and we should
> probably be careful calling them base images. Perhaps, something like
> an Application Image or Composed Image? Perhaps talking about how
> they an be used as base images, but are actually rely on a RHEL base
> image? It might not seem important in this small case, but I foresee
> massive confusion if we don't perfectly align now before we 1000s of
> images (currently at just over 100 and growing fast).
> 

In the dev world, we have called these "layered images."  But agree,
some sort of name could make messaging clearer.

> 
> Best Regards
> Scott M
> 
> [1]: http://developers.redhat.com/blog/2016/01/13/a-practical-introdu
> ction-to-docker-container-terminology/
> 
> -- 
> Scott McCarty, RHCA
> Technical Product Marketing: Containers
> Email: smccarty at redhat.com
> Phone: 312-660-3535
> Cell: 330-807-1043
> Web: http://crunchtools.com
> When should you split your application into multiple containers? http
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