NTP/Chrony Configuration on Rocky via cloud-init fails with "no template found"

[thunderboltsid]

I've encountered an issue with cloud-init on Rocky Linux that prevents NTP configuration during initialization. Rocky Linux seems to be missing the necessary template for chrony configuration. In the /var/log/cloud-init-output.log, the following warnings appear:

[2024-11-08 18:24:55] Cloud-init v. 22.1-5.el9.0.1 running 'modules:config' at Fri, 08 Nov 2024 18:24:55 +0000. Up 113.25 seconds.
[2024-11-08 18:24:55] 2024-11-08 18:24:55,312 - cloud.py[WARNING]: No template found in /etc/cloud/templates for template named chrony.conf.rocky
[2024-11-08 18:24:55] 2024-11-08 18:24:55,312 - util.py[WARNING]: Running module ntp (<module 'cloudinit.config.cc_ntp' from '/usr/lib/python3.9/site-packages/cloudinit/config/cc_ntp.py'>) failed
[2024-11-08 18:24:55] Cloud-init v. 22.1-5.el9.0.1 running 'modules:final' at Fri, 08 Nov 2024 18:24:55 +0000. Up 113.94 seconds.

Upon inspection, the chrony.conf.rocky.tmpl file is indeed missing:

# ls /etc/cloud/templates/chrony*
/etc/cloud/templates/chrony.conf.alpine.tmpl
/etc/cloud/templates/chrony.conf.debian.tmpl
/etc/cloud/templates/chrony.conf.fedora.tmpl
/etc/cloud/templates/chrony.conf.opensuse.tmpl
/etc/cloud/templates/chrony.conf.photon.tmpl
/etc/cloud/templates/chrony.conf.rhel.tmpl
/etc/cloud/templates/chrony.conf.sles.tmpl
/etc/cloud/templates/chrony.conf.ubuntu.tmpl

Cloud-init recognizes ‘rocky’ as a distro in its configuration: cloudinit/config/cc_ntp.py#L40.
Newer versions of cloud-init include logic to handle similar distros through mapping: cloudinit/config/cc_ntp.py#L241-L248 however, Rocky Linux isn’t included in this mapping.

About a year ago, there was an upstream PR addressing this issue, but it wasn’t merged: PR #4627
Earlier this year, AlmaLinux folks submitted a similar PR: PR #5235
Based on these, I’ve created a new PR to add support for Rocky Linux: PR #5864