[Airship-discuss] Airship - Multi-OS: image builds - repository per distributive

[Jean-Philippe Evrard]

On Wed, Mar 20, 2019, at 23:36, Roman Gorshunov wrote:
> Hello everyone,
> 
> We have had a few discussions previously and now have an approved spec
> [0] and a story [1] (many thanks to James Gu) which will help us to
> make Airship work with (on) various Linux distributives.
> 
> One of the first steps towards implementation of the above mentioned
> specification is an in-progress effort to support OpenSUSE as a base
> image for Airship components containers. This has started as a set of
> patches under `airship_suse` Gerrit topic [2] (many thanks to Arun
> Kant).
> 
> During the work on this patches, it has become clear that we would
> need to formalize the way we would build and publish images which are
> based on different distributives. To help with that I have created a
> PS [3] to set some rules on image builds & publishing, and left it for
> a discussion.
> 
> Discussion [3] has shown, that we have controversial opinions on
> implementation details. On a latest IRC meeting we have had I've
> volunteered to move the discussion onto the Airship community
> discussions mailing list (this one). This has been done:
>  - to reach wider audience, collect more opinions and reasoning both
> in ML and in PS,
>  - to collectively come to the conclusion and agreement on
> implementation details,
>  - to reflect decision in a PS [3] and get it merged to the specification [0],
>  - and then use specification [0] as a guidance for implementation
> ([2] and others in the future)
> 
> The topic and opinions are the following:
> 
> Topic Statement:
> Non-Ubuntu container images repository naming convention is to add a
> dash separator, following with a distributive flavour, optionally
> specifying version after dash: ``airshipit/<airship
> component>-<distributive flavour>[-<version>]``; e.g.
> ``airshipit/armada-opensuse`` (based on recommendation from `quay.io`
> technical support).
> 
> Opinion 1: I think this ended up with using tags because otherwise the
> overhead of supporting a new distribution base or version is high
> (create a new quay.io docker registry). So it would be
> 'airshipit/drydock:ubuntu-latest' or
> 'airshipit/drydock:ubuntu-<commit>'. I think to maintain that
> backwards compatibility we can say here that if no distribution base
> is in the tag, it refers to an Ubuntu based image.
> 
> Opinion 2: I agree (to use tags), although the general naming scheme
> that I've seen in the majority of other docker repositories is:
> <project version #>-<distribution flavor>-<distribution flavor
> specifics>. So for our case that would end up being
> airshipit/armada:latest-ubuntu-1604 or airshipit/armada:latest-xenial
> 
> Opinion 3: IMHO Ubuntu images should have the distro in its image name
> so it is clear and avoid any confusion when we start have suse, centos
> images etc.
> 
> Opinion 4: Should we also mandate that Ubuntu includes it (distro in
> image name), even if it is default? Just for consistency and
> transparency (otherwise, looking at the Quay website, you cannot be
> sure which distro was used).
> 
> Opinion 5: Creation of another image repository is a one time effort;
> usage of separate image repositories for different base images is a
> recommendation from Quay.io tech.support; usage of separate image
> repositories for different base images allows to easily distinguish
> between images when trying to `docker pull ...` image without
> specifying a tag (assuming :latest)
> 
> Question: would we use ``airshipit/<airship component>-<distributive
> flavour>[-<version>]:<git tag>`` or ``airshipit/<airship
> component>:<distributive flavour>[-<version>]-<git tag>``?
> 
> [0] 
> https://airship-specs.readthedocs.io/en/latest/specs/approved/airship_multi_linux_distros.html
> [1] https://storyboard.openstack.org/#!/story/2003699
> [2] https://review.openstack.org/#/q/topic:airship_suse
> [3] https://review.openstack.org/#/c/643106/
> 
> Thank you.
> 
> Best regards,
> -- Roman Gorshunov
> 
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In OSH, we (I should say Pete) have decided to use <version>-<os>. Which makes it latest-opensuse_15 , latest-ubuntu_xenial (for non openstack images), master-ubuntu_xenial, master-opensuse_15, rocky-opensuse_15, etc. 

Those are always updated images. Frozen images can be tagged when necessary. Just change the 'version' with tag or sha. We can also have labels to give extra info.

I would prefer if we used the same convention.

For the image building process, I suppose it's better if you have it directly in your repo, and reuse as much as possible what's out there. For example, reusing openstack-infra Zuul roles. OSH just builds in a single repo because we don't have the opportunity to build next to the source code.

Regards,
Jean-Philippe Evrard (evrardjp)