Updated openstack/openstack
Project: openstack/nova  303f61d1e7aa3a9c1c2a212e7646e670b09aa6c5

Retry ebtables on race

Calls to ebtables can race with libvirt and cause nova, or libvirt
to fail to apply ebtables rules.

The goal of this patch is to provide a simple fix to improve the
stability of the gate.

We now call ebtables in a simple loop that retries on failure.
Long term we want to update nova to make use of the --concurrent
flag in newer versions of ebtables. The --concurrent flag
implements a lock to prevent multiple invocations of ebtables from
racing. This will require a newer libvirt and the ability to
timeout long running execs (--concurrent can block forever if it
never gets the lock).

A future patch is forthcoming to add support for --concurrent.

DocImpact
Add ebtables_exec_attempts option (default=3).

Change-Id: I3e04782ac4678581462f9bee4bb10d5f3b223457
Partial-Bug: #1316621