Open Stack

On Tue, 2021-12-07 at 11:53 +0100, Thomas Goirand wrote:
> On 12/7/21 11:20 AM, Kamil Madáč wrote:
> > Hello,
> > 
> > I would like to ask, how to update OS-EXT-SRV-ATTR:hostname via
> > openstack CLI? We changed hostnames on bunch of instances, but metadata
> > service still serves old hostname which causes that every future rebuild
> > of instance reverts hostname (`hostname` command in instance console)
> > back to old one.
> > 
> > Kamil Madáč
> > /Slovensko IT a.s./
> 
> Looks like what you want to do is disable cloud-init editing of your VM
> hostname. This is done simply by cloud-init to stop doing this. Simply
> edit /etc/cloud/cloud.cfg and set:
> 
> preserve_hostname: true
> 
> or remove any cloud-init module from the "cloud_init_modules:" list.
> Simply remove the lines containing:
> - set_hostname
> - update_hostname
> - update_etc_hosts
> 
> I hope this helps,
> 
> Cheers,
> 
> Thomas Goirand (zigo)

To add to this, there's no way to change the hostname embedded in the instance
metadata until Xena, when we added the ability to provide a 'hostname' parameter
when creating, updating or rebuilding servers (microversion 2.90). See [1] and
[2] for more details.

Stephen

[1]https://docs.openstack.org/nova/latest/reference/api-microversion-history.html#maximum-in-xena
[2]https://specs.openstack.org/openstack/nova-specs/specs/xena/implemented/configurable-instance-hostnames.html