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

[Honza Horak]

On 10/21/2015 11:39 PM, Jim Perrin wrote:
> On 10/21/2015 04:10 PM, Brian Gollaher wrote:
>
> <large snip>
>
>> My assumption was that container names would be consistent.  Where we
>> have images built on rhel7 base that run on rhel7 and rhel8 hosts (or
>> centos7 and centos8 hosts), how do identify that the image is built with
>> rhel7 base?
>
>
> We're trying to make them consistent at least in the community space,
> without making them needlessly complex or redundant. To your question, I
> would posit that in the community space, it doesn't matter. The
> container users simply aren't interested in whether they're based on
> fedora 21 or fedora 22. The users are after the application, not the OS.
> The OS itself is largely invisible in the container ecosystem except as
> a host or base container.

I don't see a problem in Fedora, since changes between latest and 
latest-1 are quite small, so porting of application is easy, if needed.

>  From the community space, neither fedora nor centos currently create
> duplicate containers distinguished by distro version, nor has either
> party expressed interest in doing so during these discussions.
>
>
> In the business case for RH, this could easily be accomplished by
> namespacing per release, registry.access.redhat.com:rhel7/foo, with a
> link to the rhel/foo-rhel7 if the BU requires it.

Well, giving second thoughts to the Ben's idea of having an alias (in 
community variants), it seems like the way out of this, since we're 
really stalled here. How it could work:

* `docker pull centos/ruby-22-centos7` for those who care about 
stability in centos-based images the same as in rhel-based images.

* `docker pull centos/ruby-22` for those who do not care about platform

* and possibly even `docker pull centos/ruby` for those who do not care 
about version either

(again, we'd use this only for centos images)

Since we're not limited to OSBS in centos, it can be done the way all 
those images having the same ID, so no matter what name the user uses, 
it always is the same image.

The only thing we need to take care of is to run something like this 
after every image build:

```
docker tag centos/ruby-22-centos7 centos/ruby-22
docker push centos/ruby-22
docker tag centos/ruby-22-centos7 centos/ruby
docker push centos/ruby
```

Honza