Has anyone already migrate to Almalinux8 in a CentoOS7 OpenVZ container?

Has anyone already migrate to Almalinux8 in a CentOS7 OpenVZ container?

I already know is needed to upgrade to Centos8, before to install AlmaLinux8, with the migration tool:
https://wiki.almalinux.org/documentation/migration-guide.html#how-to-migrate

But there are a indication this can be made the upgrade to AlmaLinux in a container, like this post:
https://bugs.almalinux.org/view.php?id=140

But I haven't tried it myself yet.
Has anyone tried this, and did it work?

Regards,
Netino

I find seems is nearly impossible, quoted from:
https://github.com/plesk/centos2alma/issues/87

Unfortunately, the news is not optimistic. We have investigated and it appears that there is no way to use Elevate (or any other Leapp-based tool) to convert the OS inside a container. This conclusion is based on two facts:

1. The Leapp upgrade process is based on the Interim System, which upgrades certain packages. It can be described as a temporary OS that replaces CentOS 7 packages with AlmaLinux 8 packages. Leapp does not modify packages inside CentOS 7 itself but rather performs preparations and reboots into an initrd OS that performs the actual transformation.
2. When we describe containers broadly, we can consider them as a form of isolation within your kernel. So it has no own bootloader, kernel or something where you could start temporary OS.
Therefore, there is no way to start the initrd inside a container. This is why the Leapp framework and as a result our current centos2alma tool cannot be used to convert the OS inside any container (e.g., Docker, Virtuozzo, etc).

Regarding vzupgrade, if I understand correctly, it is a tool to upgrade the bare-metal server that hosts virtual machines and containers. We have attempted to use it to convert a Virtuozzo container on our side without success. Additionally, there is the vzdeploy tool that can be used to convert CentOS 7 into VZLinux 7 inside a container. However, it simply reinstalls packages from the VZLinux repository within the container. As far as I can see, it cannot convert your CentOS 7 into VZLinux 8, for example. Therefore, it does not appear to be a solution to your problem.

We are also exploring other options for container owners:

1. As far as I know, Virtuozzo allows you to convert a container into a virtual machine. And a Virtuozzo virtual machine can be converted using any leapp based instrument (including centos2alma), so this seems to be the simplest way to resolve the issue.
2. You could use the Plesk migrator tool to migrate your Plesk from the CentOS 7 container to an AlmaLinux 8 container. Obviously you have to have this AlmaLinux 8 container somewhere.
3. Try converting your container with vzdeploy into VZLinux 7 and inquire with the Virtuozzo developers if there is any way to convert VZLinux 7 to VZLinux 8 inside a container.

I hope this information will be helpful in addressing your situation. Additionally, we will reach out to the Virtuozzo developers to inquire about their perspective on the problem.