No feedback provided when unshelving Vms on systems with no capacity to unshelve

[Steven Parker]

Description
===========
User is not provided any feedback that unshelving of a VM is failing due to lack of capacity on the cloud. In fact there is no status that an error occurred resulting in the end user assuming that the openstack CLI/API may have issues executing the request.

Steps to reproduce
=================
Attempt unshelve command on system with no capacity to place the VM.

Expected result
===============
Provide feedback to end users that command failed. Either via CLI output or via the openstack server show command.

Actual result
=============
After command: openstack server unshelve is executed. We get the following status.

From nova cloud controller logs after unshelve of VM is requested via openstack CLI.

juju ssh nova-cloud-controller/0 grep dc587e54-72db-4825-96c5-13175f14460d /var/log/nova/*
/var/log/nova/nova-conductor.log:2024-06-26 21:17:23.068 10887 ERROR nova.conductor.tasks.migrate [req-9e20410f-d0d7-4309-a747-040b05b61ac9 9c75e46675c34ecc84ed6eae6c07dae3 995e6cec9fd0489fa1482f9445dee780 - default default] [instance: dc587e54-72db-4825-96c5-13175f14460d] Unable to replace resource claim on source host compute1.maas node compute1.maas for instance
/var/log/nova/nova-conductor.log:2024-06-26 21:17:23.077 10887 WARNING nova.scheduler.utils [req-9e20410f-d0d7-4309-a747-040b05b61ac9 9c75e46675c34ecc84ed6eae6c07dae3 995e6cec9fd0489fa1482f9445dee780 - default default] [instance: dc587e54-72db-4825-96c5-13175f14460d] Setting instance to ACTIVE state.: nova.exception.NoValidHost: No valid host was found. Unable to replace instance claim on source
/var/log/nova/nova-conductor.log:2024-06-26 21:17:43.369 10921 ERROR nova.conductor.tasks.migrate [req-ea08150c-c3e2-4d08-b65b-086ed4d70df2 9c75e46675c34ecc84ed6eae6c07dae3 995e6cec9fd0489fa1482f9445dee780 - default default] [instance: dc587e54-72db-4825-96c5-13175f14460d] Unable to replace resource claim on source host compute1.maas node compute1.maas for instance
/var/log/nova/nova-conductor.log:2024-06-26 21:17:43.377 10921 WARNING nova.scheduler.utils [req-ea08150c-c3e2-4d08-b65b-086ed4d70df2 9c75e46675c34ecc84ed6eae6c07dae3 995e6cec9fd0489fa1482f9445dee780 - default default] [instance: dc587e54-72db-4825-96c5-13175f14460d] Setting instance to ACTIVE state.: nova.exception.NoValidHost: No valid host was found. Unable to replace instance claim on source
/var/log/nova/nova-conductor.log:2024-06-26 21:19:37.194 10897 ERROR nova.conductor.tasks.migrate [req-b130a337-d50e-4dc3-993a-839183948597 9c75e46675c34ecc84ed6eae6c07dae3 995e6cec9fd0489fa1482f9445dee780 - default default] [instance: dc587e54-72db-4825-96c5-13175f14460d] Unable to replace resource claim on source host compute1.maas node compute1.maas for instance
/var/log/nova/nova-conductor.log:2024-06-26 21:19:37.202 10897 WARNING nova.scheduler.utils [req-b130a337-d50e-4dc3-993a-839183948597 9c75e46675c34ecc84ed6eae6c07dae3 995e6cec9fd0489fa1482f9445dee780 - default default] [instance: dc587e54-72db-4825-96c5-13175f14460d] Setting instance to STOPPED state.: nova.exception.NoValidHost: No valid host was found. Unable to replace instance claim on source
/var/log/nova/nova-scheduler.log:2024-06-26 21:21:09.217 9986 INFO nova.filters [req-c3150035-ebd6-40f4-9cd8-0d77dbfdf9b8 9c75e46675c34ecc84ed6eae6c07dae3 995e6cec9fd0489fa1482f9445dee780 - default default] Filtering removed all hosts for the request with instance ID 'dc587e54-72db-4825-96c5-13175f14460d'. Filter results: ['RetryFilter: (start: 32, end: 32)', 'AvailabilityZoneFilter: (start: 32, end: 7)', 'ComputeFilter: (start: 7, end: 7)', 'ComputeCapabilitiesFilter: (start: 7, end: 7)', 'ImagePropertiesFilter: (start: 7, end: 7)', 'ServerGroupAntiAffinityFilter: (start: 7, end: 7)', 'ServerGroupAffinityFilter: (start: 7, end: 7)', 'DifferentHostFilter: (start: 7, end: 7)', 'SameHostFilter: (start: 7, end: 7)', 'PciPassthroughFilter: (start: 7, end: 7)', 'NUMATopologyFilter: (start: 7, end: 7)', 'AggregateInstanceExtraSpecsFilter: (start: 7, end: 0)']

However status of server does not indicate failure of unshelve command:

openstack server show dc587e54-72db-4825-96c5-13175f14460d
+-------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Field | Value |
+-------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| OS-DCF:diskConfig | MANUAL |
| OS-EXT-AZ:availability_zone | |
| OS-EXT-SRV-ATTR:host | None |
| OS-EXT-SRV-ATTR:hypervisor_hostname | None |
| OS-EXT-SRV-ATTR:instance_name | instance-000005c7 |
| OS-EXT-STS:power_state | Shutdown |
| OS-EXT-STS:task_state | None |
| OS-EXT-STS:vm_state | shelved_offloaded |
| OS-SRV-USG:launched_at | 2021-06-28T05:43:36.000000 |
| OS-SRV-USG:terminated_at | None |
...

| status | SHELVED_OFFLOADED |
| updated | 2024-06-26T21:38:44Z

Environment
===========
dpkg -l | grep nova
ii nova-api-os-compute 2:21.2.4-0ubuntu2.6 all OpenStack Compute - OpenStack Compute API frontend
ii nova-common 2:21.2.4-0ubuntu2.6 all OpenStack Compute - common files
ii nova-conductor 2:21.2.4-0ubuntu2.6 all OpenStack Compute - conductor service
ii nova-scheduler 2:21.2.4-0ubuntu2.6 all OpenStack Compute - virtual machine scheduler
ii nova-spiceproxy 2:21.2.4-0ubuntu2.6 all OpenStack Compute - spice html5 proxy
ii python3-nova 2:21.2.4-0ubuntu2.6 all OpenStack Compute Python 3 libraries
ii python3-novaclient 2:17.0.0-0ubuntu1 all client library for OpenStack Compute API - 3.x

Feature Request
+++++++++++++++
Request feature to provide feedback to the end user when an unshelve command fails at least in the specific case of capacity limits causing the request to fail. |