juju model migration resets 'Inst id' display in juju status output

[Xav Paice]

Juju 2.9.22, migrating from a controller running Xenial to one running Focal, both provided by Maas.

On the original model when I run 'juju status' I get the display name of machines in the Inst id column, e.g.

Model Controller Cloud/Region Version SLA Timestamp
bootstack-preparation controller-xenial maas 2.9.22 unsupported 18:42:41Z

App Version Status Scale Charm Store Channel Rev OS Message
nagios unknown 1 nagios charmstore stable 46 ubuntu Waiting for agent initialization to finish
thruk-agent unknown 1 thruk-agent charmstore stable 13 ubuntu Waiting for agent initialization to finish

Unit Workload Agent Machine Public address Ports Message
nagios/2* active idle 43 10.36.2.3 80/tcp ready
  thruk-agent/3* active idle 10.36.2.3 ready

Machine State DNS Inst id Series AZ Message
43 started 10.36.2.3 nagios bionic default Deployed

After the upgrade, the "Inst id" column displays the Maas machine ID.

If I run 'juju show-machine 43' it shows me `hostname: nagios`, `instance-id: xn3qm4`, `dns-name: 10.36.2.3`, but previously there was also a `display-name: nagios` field which seems to have disappeared on migration.

Is there any way to get these back?

[Heather Lanigan (hmlanigan)]

Doubled checked the migration export and import code, the DisplayName is not included in the description package, nor part of newCloudInstanceArgs. Migration needs to be updated.

[Canonical Juju QA Bot (juju-qa-bot)]

This Medium-priority bug has not been updated in 60 days, so we're marking it Low importance. If you believe this is incorrect, please update the importance.

[German Mazurenko (german-m)]

Faced same problem after migration from 2.8.6 to 2.9.45. And only on our main cluster. I've done 4 migrations before and they were all ok. Except for last one. All new machines(created after migration) in this model have "normal" name, but old ones use maas system_id (instead of hostname) as inst id.