changing the FQDN, and not the hostname, in a cluster

[lethargos]

Hello,

I would like to change the FQDN in a cluster which we mainly use to access the administrative interface.
I see that in /etc/hosts both the fqdn and the one-label names are set:

127.0.0.1 localhost.localdomain localhost
10.88.88.231 pve1.example.com pve1
10.88.88.232 pve2.example.com pve2
10.88.88.233 pve6.example.com pve6
10.88.88.236 pve3.example.com pve3
10.88.88.239 pve8.example.com pve8
10.88.88.238 pve7.example.com pve7
10.88.88.237 pve4.example.com pve4

We are accessing the cluster using pve1.example.com (or pve2.example.com, etc.), but we would like to use pve1.otherdomain.com and so move away from example.com.
I can also see that the ssh keys of the Proxmox nodes have the short name root@pve1, root@pve2 and so on and so forth.

Would it be safe to assume that Proxmox doesn't use the FQDN for any important internal mechanisms and simply change it?

We actually want to use a different domain for our certificates which we'd want to renew automatically, but the API token can only be restricted to the whole zone, and not to particular A records, so that's why we'd prefer to use a separate zone for this purpose.

pveversion: pve-manager/8.1.4/ec5affc9e41f1d79 (running kernel: 6.5.11-8-pve)

 

[jsterr]

Hello,

I would like to change the FQDN in a cluster which we mainly use to access the administrative interface.
I see that in /etc/hosts both the fqdn and the one-label names are set:

127.0.0.1 localhost.localdomain localhost
10.88.88.231 pve1.example.com pve1
10.88.88.232 pve2.example.com pve2
10.88.88.233 pve6.example.com pve6
10.88.88.236 pve3.example.com pve3
10.88.88.239 pve8.example.com pve8
10.88.88.238 pve7.example.com pve7
10.88.88.237 pve4.example.com pve4

We are accessing the cluster using pve1.example.com (or pve2.example.com, etc.), but we would like to use pve1.otherdomain.com and so move away from example.com.
I can also see that the ssh keys of the Proxmox nodes have the short name root@pve1, root@pve2 and so on and so forth.

Would it be safe to assume that Proxmox doesn't use the FQDN for any important internal mechanisms and simply change it?

We actually want to use a different domain for our certificates which we'd want to renew automatically, but the API token can only be restricted to the whole zone, and not to particular A records, so that's why we'd prefer to use a separate zone for this purpose.

pveversion: pve-manager/8.1.4/ec5affc9e41f1d79 (running kernel: 6.5.11-8-pve)

Yes. You can easily change it in /etc/hosts. Might need a pvecm updatecerts -f afterwards. Verify fqdn before pvecm-command with hostname -f

 

[lethargos]

hostname -f shows pve1.example.com. So to what extent should I be worried?

 

[jsterr]

hostname -f shows pve1.example.com. So to what extent should I worried?

The hostname gets only used if you use it for web-access, you can still always ACCESS the web-ui via https://ip:8006 no matter what. Aslong as you dont use the pve1.example.com domain internally for something special like scripts, monitoring-tools api calls via web instead of IP etc. you should not worry at all. if you use the dns names in scripts or anywhere else, change them after beeing reachable after the change in pve.

hostname -f should show the new fqdn (hostname+ new domain) after you changed it in /etc/hosts. Might also need a reboot to be active, maybe a ssh reconnect does also work.