Add composefile schema 3.7 with platform

[vdemeester]

It's ignored for now (docker stack deploy) and will print a warning if present.

Fixes #1050

That being said, I think one easy fix to that issue would be to add platform to v3 schema(s) — but it would start at schema 3.7 — and printing a warning when issuing a docker stack deploy that this field is not supported (same way we do it for build). It would allow to more easily updated from v2 to v3 for users and help us not make v2 and v3 schema diverge that much — at least not having elements in v2 that are not in v3…

Also linked to docker/compose#5985

Signed-off-by: Vincent Demeester [email protected]

[silvin-lubecki]

LGTM

[shin-]

Are we really okay with adding non-Swarm compatible options to v3? I'm asking because it's a significant depart from our strategy so far (with the exception of build sub-options) and I'm curious how it'll affect user experience.

I'm guessing the rationale is that Swarm (/kube?) will support the option eventually?

[vdemeester]

I'm guessing the rationale is that Swarm (/kube?) will support the option eventually?

Yes, that's part of the rationale — other part is I really wish we have as divergence between v2 and v3 composefile evolution 👼

[thaJeztah]

I think this requires more eyes; LCOW (and thus the --platform option) is still experimental, and things may change (possibly including the format of the --platform string (e.g., on Windows, some situations not only require the platform and architecture, but also OS version 😞 (IIRC))

I'm also a bit out of sync with the discussion around that (i.e, what format the --platform should take; string, or structured approach)

ping @johnstep @jhowardmsft PTAL

[jetersen]

How rigid do you want to be? Docker compose should perhaps support an experimental flag just like the docker for windows? So that we can get to try out the new stuff. Maybe I am asking for too much, I don't know. 🤔

[thaJeztah]

How rigid do you want to be?

Well, a spec, once published, cannot be changed, so that's why I want to be sure it's finalised and agreed on.

Docker compose should perhaps support an experimental flag

Having this as an extension field (x-platform: foo) would be an option for that

[vdemeester]

So the x-* should be handled by the following PR : #1097

That said, platform is already present in v2.. and if that version of v2 has been released, we can't really transform it to a x-platform and thus, I really think we should at least have it in v3 even though it will be ignored. Otherwise (i.e. v2.4 support is not shipped in a release), we could transform it to `x-platform)

cc @dnephin @shin-

[vdemeester]

Closing this as it staled 😓

[jetersen]

no worries @vdemeester fixed by the auto-detection, so it's fine :)