[scl.org] Image naming for centos-based images

Honza Horak hhorak at redhat.com
Tue Oct 20 21:29:53 UTC 2015

I'm wondering whether the silence means nobody has any objections or 
whether everything was already said..

Anyway, there is still the risk of using names without rhel7 and centos7 
suffix like `centos/mariadb-100` or `rhscl/mariadb-100`, that user won't 
be sure what is the OS version in the container -- that is considered 
relevant in more parts of 

That ^ is also the view I'm more leaned towards, simply because I agree 
with the points in the document above and because I don't think platform 
version makes any harm in the name. On the other hand, the Docker world 
works without platform version or even component version in the name, so 
it shouldn't be that bad in the end.

So, technically we're able to change the names for RHSCL images now 
after they are available as Beta, but I'm not sure whether it is still 
possible from PM PoV -- Brian, would it be possible to change names of 
the images from e.g. `rhscl/mariadb-100-rhel7` to `rhscl/mariadb-100` at 
this point?


On 10/09/2015 09:41 PM, Ben Parees wrote:
> Karanbir and I talked briefly today, and i'd like to just lay out a
> couple things from an openshift perspective:
> 1) we encourage the use of both rhel and centos images (rhel for
> support, centos to try), so we really want the images to have the same
> names (other than the namespace/org) because it makes for a much more
> consistent transition, better support experience, etc.  So i do not like
> any approach that results in one naming convention for centos images and
> another for the "rhscl" images.
> 2) we're shipping OSE3.1 nov 19th and things need to be locked down
> earlier than that.  Since this will be the first release shipping these
> new SCL images, we have some freedom to change the names now.  But once
> that happens it's going to be much more painful to change them.  So if
> things are changing, we need a decision asap.
> 3) I suggested that maybe we could use aliases to solve some of this...
> you can still provide a "mariadb" docker alias for the seamless "i don't
> care what i get" experience, but still maintain multiple streams of
> versions/etc by backing that alias with a more specifically named pull
> spec, like the names we use today.
> 4) i'm mostly willing to concede dropping the rhel7/centos7 suffice from
> the names now that we have separate namespaces for the
> repositories...but keeping the version number in the name still seems
> important to avoid the issues with users not being able to pull "latest"
> or not understand what they have pulled.
> I'm also adding Dan McPherson and Clayton Coleman to this thread as they
> are the lead architects for OpenShift and should also weigh in on any
> image naming decisions we're making.
> On Thu, Oct 8, 2015 at 11:43 AM, Honza Horak <hhorak at redhat.com
> <mailto:hhorak at redhat.com>> wrote:
>     On 10/07/2015 11:40 AM, Karanbir Singh wrote:
>                 variant B: centos/mariadb:10.0
>             * less complicated * no redundancy * it is similar to what
>             docker
>             hub uses for official images now
>         adding a few more bits here for B :
>         * pretty much the standard way for the entire docker ecosystem
>         to work
>         on right now ( that redhat is largely absent from )
>     Fair point. Anyway, what a sane user actually does IMO is not
>     `docker pull mariadb`, but rather `docker pull mariadb:5.5`. And
>     since `docker search centos/mariadb` doesn't show available
>     versions, how can user know which versions are available? there is
>     only centos/mariadb in the output.
>     So, user can only guess what versions are available or can find it
>     somewhere else.. in the case there would be the version in the image
>     name, it would be listed in the search output, which seems like a
>     benefit for user to me.
>     Btw. did you know that there has been already centos/mariadb
>     available on docker hub?
>         * provides scope for future expansion as we abstract away from
>         delivery mechanics to focus on payload
>     I still don't consider this to be related to delivery mechanism.
>         * allows for distro decompose and co-exist in a 'as default'
>         manner (
>         admittedly arguable! )
>         A relatively sane proof for this model is looking at how many people
>         run a 'yum install mariadb' V/s 'yum install
>         mariadb-5.5.44-1.el7_1.x86_64' when they want a mariadb install;
>         having a centos/mariadb and using tag space to extend the multiple
>         version availability, allows us to extend the same user expectation.
>     Sure, nobody runs 'yum install mariadb-5.5.44-1.el7_1.x86_64' and
>     just uses `mariadb`, but we must realize that users always install
>     RPMs for the correct platform (nobody configures yum to install el6
>     packages on el7) and we also provide only one version of the mariadb
>     in the system, so users are sure what version they get. Once there
>     are more versions (as SCLs or if we find any other format), users
>     will install particular version -- `yum install mariadb55`, because
>     they care (in most cases).
>     Docker is new in this sense because you have all versions build on
>     various kernels on one heap. This is not something we have
>     experience with in RPM world.
>             As mentioned in this thread [2], there is a new API spec being
>             prepared [3], which will be a chance to change naming scheme to
>             something less redundant, if the current way proofs to be
>             problematic.
>         [1] isnt complete so its clearly a work in progress, how about
>         we just
>         work on getting that complete now and address the whole piece
>         together
>         ? or is the SCL portion left as TBA allowing the scl space to do
>         something completely different ?
>     The SCL part is there already, but covers only RH registry. I wish
>     we could sync on one schema over Fedora/RHEL/CentOS as well, but I
>     don't see a compromise here, that would be fine for all. Or maybe
>     missing willingness to accept some compromise, I don't know.
>         Secondly, if you consider the inertia against looking at a
>         change now
>         largely driven by we-already-have-something, what are the
>         chances that
>         this is going to go away when the api-spec comes up ( and we
>         have even
>         more water under the bridge ? ).
>     IMO the chance would be big enough if we'll be convinced the current
>     way is not good enough for users. If we'll see the current way is
>     fine for them and doesn't make any troubles, then why changing it..
>     Honza
> --
> Ben Parees | OpenShift

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