Re: [atomic-devel] docs-first RFE for stripping containers

[Subhendu Ghosh <sghosh redhat com>]

Take a look at the  Openshift build system in Origin. It's implementing that workflow for a local registry.

-------- Original message --------

From: "M. Edward (Ed) Borasky" <znmeb znmeb net>

Date:02/06/2015 02:42 (GMT+01:00)

To: atomic-devel projectatomic io

Cc:

Subject: Re: [atomic-devel] docs-first RFE for stripping containers

I need / want something like this very badly. My workflow is basically:

1. Build a development image with all the source, build-time dependencies, etc.
2. Do the builds and export tarballs to my workstation host filesystem
or "someplace on the internet".
3. Build an image with the run-time dependencies and tarballs and
'docker push' it to Docker Hub.

*However* - this needs to be *100%* automated / continuously
integrated / reproducible from upstream source code to finished Docker
Hub image. I'm not there yet. Docker Hub's not there yet. And I have a
half-dozen other itches I want to scratch. ;-)

If I had that, the runtime image wouldn't need 'yum' or 'dnf' -
run-time Fedora dependencies would be updated and a new image made
automagically. I don't know the Docker Hub infrastructure well enough
to build this - I'd have to build a host somewhere and hook into a few
APIs and do a 'docker push' at the end.

On Thu, Feb 5, 2015 at 12:49 PM, Jim Perrin <jperrin centos org> wrote:
>
>
> On 02/05/2015 01:56 PM, SGhosh wrote:
>>
>>
>> I don't think you want to go as far as you are suggesting.
>> Having the concept of RPMs and dependecy is useful mechanism for being
>> able to install apps on top of an existing image, and it is useful if
>> you need to apply an emergency fix before rebuilt image can be deployed.
>>
>
> I'm viewing this more as a a final optional step in the workflow for
> production and deployment, not necessarily for base images.
>
>
>> Cutting down in size is a useful requirement - and getting some upstream
>> help for that is needed as well. The latest RPM changes about to hit
>> Fedora will include strong/weak dependencies - that can be used to
>> remove some deps based on full rms nots being installed. But this is not
>> a CentOS 7 item.
>
> That sounds interesting. I wouldn't suggest this strictly as a CentOS
> thing, but more as an acceptance of containers as a packaging method
> itself.
>
>> yum does have the excludedocs feature - and utilizing that can reduce
>> some of the content - but not all.
>
> We do this already, as well as some limited file abuse in the case of
> glibc locales. This still leaves a fairly minimal OS container weighing
> in at around 150-250MB before the actual applications get installed.
> Once everything is built to satisfaction, the admin/dev could simply
> strip it and deploy as a final step if needed/desired.
>
>
> --
> Jim Perrin
> The CentOS Project | http://www.centos.org
>