Cheers for looking, Wei.
Yes, indeed, there's more than one way to skin a cat and producing other
formats is one qemu-img command away.
https://www.nux.ro/Upstream_Linux_cloud_images_and_Cloudstack/
If we can at least agree on the basic concepts then that's the important
bit.
Regardless of method (virt-*, packer etc), we should clarify (SSH)
access into the template and whether my approach is OK or not.
On 2026-10-16 10:02, Wei ZHOU wrote:
Hi Lucian,
Thanks for sharing. I agree that Debian 13 would be a nice option.
The script looks good and the steps are very similar to one I am
working
on. Mine supports customizing other cloud images (Debian, of course, as
well as Ubuntu, Rocky, AlmaLinux, etc.) and converting them into
specific
formats.
Packer would be a good option for production templates. However,
customizing existing cloud images is much easier and faster - I can get
qcow2, VHD, and OVA templates ready in about 10 minutes. Sorry @Wido
den
Hollander <[email protected]>
-Wei
On Thu, Oct 15, 2026 at 3:10 AM Nux <[email protected]> wrote:
I've manipulated a Debian 13 genericcloud image into a possible
CloudStack default template.
Build script and samples here, everything is explained in the script,
I'd appreciate your thoughts, especially around security and SSH
access.
https://jenkins.openvm.eu/files/deftmpl/
Lucian
On 2026-10-12 10:14, Kiran Chavala wrote:
> Subject: [DISCUSS] Replacing the default built-in CentOS template in
> CloudStack
>
> Hi all,
>
> I'd like to start a discussion on replacing the default built-in
> template
> that ships with every CloudStack installation.
>
> The original GitHub discussion is here, and you're welcome to comment
> there
> as well:
> https://github.com/apache/cloudstack/discussions/13797
>
> Today, the built-in templates registered for each hypervisor are quite
> outdated:
>
> - KVM: CentOS 5.5 (64-bit) no GUI
>
>
http://download.cloudstack.org/releases/2.2.0/eec2209b-9875-3c8d-92be-c001bd8a0faf.qcow2.bz2
> - XenServer: CentOS 5.6 (64-bit) no GUI
>
> http://download.cloudstack.org/templates/builtin/centos56-x86_64.vhd.bz2
> - vSphere: CentOS 5.3 (64-bit) no GUI
> http://download.cloudstack.org/releases/2.2.0/CentOS5.3-x86_64.ova
>
> These templates are no longer practical, even for basic testing:
>
> 1. The VM deploys, but the SSH service doesn't work, so it's of little
> use
> for validating a fresh installation.
> 2. They're starting to break outright on newer hypervisors. On ACS 4.22
> with XenServer 8.4, deploying a VM from the default CentOS template
> fails
> with "Cannot find Template CentOS 7 on XenServer host", because
> XenServer
> 8.4 has deprecated the CentOS 7 guest template (tracked in
> https://github.com/apache/cloudstack/issues/13798).
>
> What I'd like to see is a new default template that is:
>
> - current, and in line with what users actually run today
> - small in footprint, so it downloads quickly and can be used for quick
> testing right after installation
> - functional for the core guest features: root password reset, SSH
> keys,
> user data, and cloud-init
>
> Candidates I've looked at:
>
> - macchinina (https://github.com/NuxRo/macchinina)
> - Alpine Linux cloud images (https://alpinelinux.org/cloud/)
> - CirrOS (https://github.com/cirros-dev/cirros)
> - Debian cloud images (https://cloud.debian.org/images/cloud/)
> - Ubuntu minimal cloud images (
> https://cloud-images.ubuntu.com/minimal/releases/)
> - AlmaLinux Generic Cloud (
> https://wiki.almalinux.org/cloud/Generic-cloud.html)
> - Rocky Linux (https://wiki.rockylinux.org/rocky/image/)
> - Fedora Cloud (https://fedoraproject.org/cloud/download/)
>
> My personal preference is between two options:
>
> 1. macchinina: built for CloudStack testing, but it needs a refresh and
> someone to maintain it going forward.
> 2. Alpine cloud image: very small and well maintained upstream. We'd
> need
> to run tests to confirm password, SSH key, and user-data behaviour
> across
> hypervisors.
>
> Most of the mainstream distro cloud images are in the 500-600 MB range,
> which goes against the "quick test after install" goal.
>
> I'd love to hear the community's views on:
>
> - which image (or images) you'd prefer as the default
> - any hypervisor-specific concerns (KVM / XenServer-XCP-ng / VMware)
>
>
> If there's rough consensus, I'm happy to follow up with a PR and
> testing
> across hypervisors.
>
> Thanks,
> Kiran Chavala
