Keep config drive in swift until server deletion

[xiaobin]

Currently if configdrive_use_swift is set, config drive will be uploaded to swift with header:
{'X-Delete-After': timeout}
Which means config drive will be removed after "timeout" seconds.
If the server is rebuilt "timeout" seconds later, config drive won't be available, provisioning will fail.

Proposal:
1. Do not pass 'X-Delete-After' header
2. Delete config drive during server deletion
3. If config drive is allowed in "rebuild" call (Bug 1575935), override previous config drive.

UPD by dtantsur: we still must expire the temporary URL and generate a new one on rebuild.

[Dmitry Tantsur (divius)]

We need to fix rebuild, not keep configdrive in Swifr forever (this is a security concern).

[Dmitry Tantsur (divius)]

Correction: we can and should keep the configdrive in swift, but we should expire the temporary URL for it, and renew it on rebuilt.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/355142

[Jay Faulkner (jason-oldos)]

I do not agree that the symptom described should be fixed by keeping the configdrive past server delete. For other Nova drivers, configdrive is regenerated on rebuild (https://github.com/openstack/nova/blob/0da6c6461177539cf69c7c2998f3ce8914112b0a/nova/compute/manager.py#L2576) based on user input, so that we are currently:

1) ignoring user data passed into rebuild and
2) providing different behavior than other nova drivers (by preserving configdrive contents).

I instead propose that post-deployment, we remove the configdrive from the node immediately after deployment, and rebuilding in Ironic will always require re-adding configdrive information to the node.

[Mathieu Mitchell (mat128)]

I agree with Jay's proposal. It is better aligned with the other drivers *and* submitting more user-data on rebuild will work.

[Lucas Alvares Gomes (lucasagomes)]

Thanks Jay for the comment. I also agree that would be the right way of fixing this problem.

[xiaobin (jxiaobin)]

True, bug 1575935 is the final fix, but it's still "Wishlist", I see no progress on it.
Once 1575935 is resolved, user data during rebuild will still be accepted.

[OpenStack Infra (hudson-openstack)]

Change abandoned by jxiaobin (<email address hidden>) on branch: master
Review: https://review.openstack.org/355142