compose: Stabilize --lockfile

[cgwalters]

We have a lot of experimental features. Lockfiles have been
in use successfully in FCOS for quite a while now. While there
are probably things we could improve here, in the end we need
to support what we have today for a long time, so let's just mark
it stable.

Motivated by reducing our number of experimental features (to
pave the way for adding more, i.e. the container bits), as well
as a side conversation I had around supporting skipping depsolve
since that's what osbuild wants.

[lucab]

If you aren't in a hurry about this, before finalizing lockfile support (and by extension its current format) I'd like to double-check that it suits possible usage by osbuild, and if not tweak it before stabilizing it.

[cgwalters]

Sure, SGTM.
That said, if any changes are required, we'll still have to support the current interface for quite a while while FCOS adapts, and it's not clear to me that "a while" isn't "forever".

[jlebon]

From my POV, I agree it's about time we stabilize these. We might extend the schema, though it's unlikely we'll modify existing keys. I wouldn't shy away from deleting even the --ex aliases in a near future release once cosa has migrated over because AFAIK it's the only consumer.

[lucab]

Dedicated ticket at #3204.

For reference, I was more concerned about the overall flow, while the lockfile JSON format may possibly be fine as is. I do recall cargo making many missteps when approachin this same topics, see the subtle differences between --locked / --frozen / --offline / vendor.

[openshift-ci]

@cgwalters: PR needs rebase.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[openshift-ci]

@cgwalters: The following tests failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
ci/prow/fcos-e2e	f210935	link	true	/test fcos-e2e
ci/prow/clang-analyzer	f210935	link	true	/test clang-analyzer
ci/prow/images	f210935	link	true	/test images
ci/prow/build-clang	f210935	link	true	/test build-clang
ci/prow/kola-upgrade	f210935	link	true	/test kola-upgrade

Full PR test history. Your PR dashboard.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository. I understand the commands that are listed here.