Purge the compute_node records, resource provider records and host_mappings when doing force delete of the host

[Surya Seetharaman]

The nova-manage cell_v2 delete_cell --force option currently only removes the host_mappings of empty hosts before deleting the cell. This has to be extended to deleting the nova.compute_nodes record and nova_api.resource_providers along with the host_mappings for those hosts which have no living instances.

The nova-manage cell_v2 delete_host needs to have a new option --force by which when a host is deleted forcefully, if it has no living instances then again its nova.compute_node record and nova_api.resource_provider along with its host_mapping should be removed.

[Surya Seetharaman (tssurya)]

Bug has been filed following the discussion on IRC : http://eavesdrop.openstack.org/irclogs/%23openstack-nova/%23openstack-nova.2018-02-14.log.html#t2018-02-14T15:08:39

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/546660

[Matt Riedemann (mriedem)]

This is arguably a duplicate of bug 1756179 which is already resolved now - DELETE /os-services/{id} will now delete resource provider and host mapping for a compute service record when deleting the service via the REST API.

[Surya Seetharaman (tssurya)]

Since implementing this on delete_host command would make this a copy of nova service-list, we now focus only on delete_cell; tbh I am not sure what's the goal of having delete_host.. maybe to just delete the host_mapping and re-create the host mapping in the same cell? -> wondering what's the use case for that.