WIP: Add pod/commit subsource to support user to commit their container

[mqliang]

This PR add pod/commit subsource to support user to commit their image.

I didn't try to fully implement this(I even not update the auto generated files) since some discussion may needed.

If this looks good, I will implement the kubelet&kubectl part and implement the pod/push subsource to support user to push their container to registry.

Kubelet will support the commit/push functionality by some abstraction mediating the runtime(docker and rkt by now), so that it's runtime-agnostic.

It seems that rkt doesn't support commit&push by now(correct me if I am wrong), we can return a error message(indicating that the command is not supported) to user until rkt support commit/push.

Any comment are welcomed.

[k8s-bot]

GCE e2e build/test failed for commit 5447f62.

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[mqliang]

@smarterclayton @davidopp @bparees @ironcladlou @bgrant0607 Could you please give me some feedback?

[bgrant0607]

cc @derekwaynecarr

[k8s-bot]

GCE e2e build/test failed for commit 5447f62.

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[bgrant0607]

@mqliang Sorry, we have a huge backlog right now and the 1.2 deadline is fast approaching, so it may be a while before we can get to this.

Could you explain a bit more about how you expect this to be used? Does the container need to be running? Not running? If not running, what would prevent the container from being garbage collected?

Would imagePullSecrets also be used for push?

cc @ncdc

[mqliang]

Does the container need to be running? Not running? If not running, what would prevent the container from being garbage collected?

I expect user commit/push their container manually, so the container need to be running. If user want push/commit their container automatically, we can add a pod life-cycle hook to support commit+push after container exits(which is proposed by @derekwaynecarr #14561).

Would imagePullSecrets also be used for push?

I am afraid not. I think we would have a ImagePushSecret required or something similar to be used for push.

I didn't try to fully implement this since some discussion may needed. I will make this open and get more feedback before the full implementation.

[derekwaynecarr]

I also am interested in this capability but there are a number of side-effects that we need to account. For example, if an image is committed, do we guarantee that it will not be evicted for some period of time? How can I push a committed image to a registry in an environment where I don't have access to the node, etc. Can you put together a proposal document that starts to explore some of these questions that we can assess post kube 1.2?

[mqliang]

@derekwaynecarr Ok, I will send a proposal ASAP.

[k8s-github-robot]

PR needs rebase

[fejta]

This PR has had no meaningful activity for multiple months. If it is still valid please rebase, push a new commit and reopen the PR. Thanks!