Disassociate failed dhcp fixed ip in deallocate_for_instance() method

[Yufang Zhang]

Currently, fix_ip disassociation only happens in release_fixed_ip(), which is called by dhcp-bridge when ip is released. But there are circumstances when instancs fail to get lease from dnsmasq(instances fail to boot or instances fail to spawn). In such case, DHCPRELEASE packet sent to dnsmasq would not trigger dhcp-bridge to run. Thus the fixed ip would not be disassociated from instance until _disassociate_stale_fixed_ips() begins to run. We need a fix for this problem.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/29361

[Yufang Zhang (yufang521247)]

Step to reproduce this bug:

1. create an instance in nova
2. stop libvirtd before the instance spawns successfully

Results:
Instance fails to spawn, and the fixed ip associated with the instance is not released when instance is re-scheduled. After some time(fixed_ip_disassociate_timeout)， the fixed ip is returned back to pool.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/34688

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/34688
Committed: http://github.com/openstack/nova/commit/383ca6cf5ff9172a43339dbf845245fbdf2f8210
Submitter: Jenkins
Branch: master

commit 383ca6cf5ff9172a43339dbf845245fbdf2f8210
Author: Yufang Zhang <email address hidden>
Date: Thu May 16 19:42:36 2013 +0800

    Disassociate fixed IPs not known to dnsmasq

    Currently, fix_ip disassociation only happens in release_fixed_ip(),
    which is called by dhcp-bridge script when ip is released. But there
    are circumstances when instancs fail to get lease from dnsmasq(instances
    fail to boot or instances fail to spawn). In such case, DHCPRELEASE
    packet sent to dnsmasq would never trigger dhcp-bridge to run. Thus the
    fixed ip would not be disassociated from instance until
    _disassociate_stale_fixed_ips() begins to run.

    Actually, this patch borrows the idea from Vishvananda's
    3f6739e2a8acdf20d01c0b5039a33f26d879587b commit: explicitly disassociate
    fixed ip which is not known to dnsmasq, instead of via the dhcp-release
    script.

    Steps to reproduce:
    1. Create an instance which doesn't send dhcp request to dnsmasq.
    2. Delete the instance.
    3. The fixed ip associated with the instance is not returned to pool.

    Bug 1180766

    Change-Id: Icc022ea2fb7af08fb7354e3a49c77ad5ae58f34c

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/grizzly
Review: https://review.openstack.org/36573

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/grizzly
Review: https://review.openstack.org/36580

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/36580
Committed: http://github.com/openstack/nova/commit/7fae6661b894596b45ec31e70627b76a643276d8
Submitter: Jenkins
Branch: stable/grizzly

commit 7fae6661b894596b45ec31e70627b76a643276d8
Author: Yufang Zhang <email address hidden>
Date: Thu May 16 19:42:36 2013 +0800

    Disassociate fixed IPs not known to dnsmasq

    Currently, fix_ip disassociation only happens in release_fixed_ip(),
    which is called by dhcp-bridge script when ip is released. But there
    are circumstances when instancs fail to get lease from dnsmasq(instances
    fail to boot or instances fail to spawn). In such case, DHCPRELEASE
    packet sent to dnsmasq would never trigger dhcp-bridge to run. Thus the
    fixed ip would not be disassociated from instance until
    _disassociate_stale_fixed_ips() begins to run.

    Actually, this patch borrows the idea from Vishvananda's
    3f6739e2a8acdf20d01c0b5039a33f26d879587b commit: explicitly disassociate
    fixed ip which is not known to dnsmasq, instead of via the dhcp-release
    script.

    Steps to reproduce:
    1. Create an instance which doesn't send dhcp request to dnsmasq.
    2. Delete the instance.
    3. The fixed ip associated with the instance is not returned to pool.

    Bug 1180766

    Change-Id: Icc022ea2fb7af08fb7354e3a49c77ad5ae58f34c
    (cherry picked from commit 383ca6cf5ff9172a43339dbf845245fbdf2f8210)

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/folsom
Review: https://review.openstack.org/39345