cc-set-hostname (hostname and fqdn) are not working on google cloud VMs Ubuntu 24.04

[rajannpatel]

Bug report

The steps here do not seem to impact the hostname on google cloud VMs:
https://cloudinit.readthedocs.io/en/latest/reference/modules.html#mod-cc-set-hostname

Steps to reproduce the problem

This cloud-init.yaml file, when used to launch a virtual machine on Google Cloud, does not make any changes to the hostname.

## template: jinja
#cloud-init

{% set HOSTNAME = 'www' %}
{% set FQDN = 'www.example.com' %}

hostname: {{ HOSTNAME }}
fqdn: {{ FQDN }}
prefer_fqdn_over_hostname: true

This is tested with the hostname command, once the machine boots up.

Environment details

• Cloud-init version: cloud-init 24.4-0ubuntu1~24.04.2
• Operating System Distribution: Ubuntu 24.04.2
• Cloud provider, platform or installer type: Google Cloud

[TheRealFalcon]

On Noble and above on GCE, setting the hostname also requires create_hostname_file: true. Does adding that change work for you?

[rajannpatel]

No, I tried with and without, and it doesn't set the hostname or fqdn either way

[TheRealFalcon]

@rajannpatel , whoops, looks like your header is wrong. #cloud-init should be #cloud-config. Though we do have a related issue on Plucky, I don't think that this is a problem on Noble.

[rajannpatel]

That's embarassing. I guess it's working as intended, for posterity I'm including some outputs from tests which appear to be working. I don't understand why I'm seeing some akamai domains in the output, but perhaps that is a byproduct of me using "example.com"

If this looks right to you, we can close this ticket.

Welcome to Ubuntu 24.04.2 LTS (GNU/Linux 6.8.0-1021-gcp x86_64)

 * Documentation:  https://help.ubuntu.com
 * Management:     https://landscape.canonical.com
 * Support:        https://ubuntu.com/pro

 System information as of Thu Feb 27 00:17:30 UTC 2025

  System load:  1.24              Processes:             112
  Usage of /:   23.6% of 8.65GB   Users logged in:       0
  Memory usage: 5%                IPv4 address for ens4: 10.128.0.42
  Swap usage:   0%

Expanded Security Maintenance for Applications is not enabled.

0 updates can be applied immediately.

Enable ESM Apps to receive additional future security updates.
See https://ubuntu.com/esm or run: sudo pro status


The list of available updates is more than a week old.
To check for new updates run: sudo apt update


The programs included with the Ubuntu system are free software;
the exact distribution terms for each program are described in the
individual files in /usr/share/doc/*/copyright.

Ubuntu comes with ABSOLUTELY NO WARRANTY, to the extent permitted by
applicable law.

rajannpatel@www:~$ cloud-init query -f "$(sudo cloud-init query userdata)"
## template: jinja
#cloud-config


hostname: www
fqdn: www.example.com
create_hostname_file: true
rajannpatel@www:~$ hostname --domain
rajannpatel@www:~$ hostname --fqdn
www
rajannpatel@www:~$ hostname --short
www
rajannpatel@www:~$ hostname --long
www
rajannpatel@www:~$ hostname --all-fqdns
instance-20250227-001455.us-central1-c.c.ubuntu-pbx.internal 
rajannpatel@www:~$ hostname --alias

rajannpatel@www:~$ hostname --yp
hostname: Local domain name not set

Welcome to Ubuntu 24.04.2 LTS (GNU/Linux 6.8.0-1021-gcp x86_64)

 * Documentation:  https://help.ubuntu.com
 * Management:     https://landscape.canonical.com
 * Support:        https://ubuntu.com/pro

 System information as of Thu Feb 27 00:25:56 UTC 2025

  System load:  1.21              Processes:             114
  Usage of /:   23.7% of 8.65GB   Users logged in:       0
  Memory usage: 6%                IPv4 address for ens4: 10.128.0.43
  Swap usage:   0%

Expanded Security Maintenance for Applications is not enabled.

0 updates can be applied immediately.

Enable ESM Apps to receive additional future security updates.
See https://ubuntu.com/esm or run: sudo pro status


The list of available updates is more than a week old.
To check for new updates run: sudo apt update


The programs included with the Ubuntu system are free software;
the exact distribution terms for each program are described in the
individual files in /usr/share/doc/*/copyright.

Ubuntu comes with ABSOLUTELY NO WARRANTY, to the extent permitted by
applicable law.

rajannpatel@www:~$ cloud-init query -f "$(sudo cloud-init query userdata)"
## template: jinja
#cloud-config


hostname: www
fqdn: www.example.com
create_hostname_file: true
prefer_fqdn_over_hostname: true
rajannpatel@www:~$ hostname --domain
dscr.akamai.net
rajannpatel@www:~$ hostname --fqdn
a1422.dscr.akamai.net
rajannpatel@www:~$ hostname --short
www
rajannpatel@www:~$ hostname --long
a1422.dscr.akamai.net
rajannpatel@www:~$ hostname --all-fqdns
fqdn.us-central1-c.c.ubuntu-pbx.internal 
rajannpatel@www:~$ hostname --alias
www.example.com www.example.com-v4.edgesuite.net
rajannpatel@www:~$ hostname --yp
hostname: Local domain name not set