support setting live_migration_timeout_action

[Andrea Ieri]

bug 1861986 requests the ability to set the live migration timeout. Option live_migration_timeout_action is basically the other side of that value, since it allows nova to autoselect a migration strategy (pause/auto-converge/post-copy) without requiring the operator to force-complete migrations.

It would be great if the charm allowed us to configure this option.

Reference: https://docs.openstack.org/nova/stein/configuration/config.html#libvirt.live_migration_timeout_action

[Adam Dyess (addyess)]

i am not completely convinced live_migration_timeout_action has much to do with 'auto-converge'. From my reading of nova and docs above auto-converge starts the MOMENT migration begins -- unless post-copy is enabled at which auto-converge is ignored.

https://github.com/openstack/nova/blob/master/nova/virt/libvirt/driver.py#L1151