Re: suggestions sought for migrating from Xen to K8

[Mike <debian@xxxxxxxxxxxxxxxxxxxxx>]

Miles Fidelman wrote:
> The version of Xen I'm running doesn't seem to store image files at all.

The "image" that I was referring to is a Docker or OCI image.  It's a
completely new entity from anything that you'd find in Xen.  It's basically
a tar file formatted in a certain way that Kubernetes knows how to load, to
create a container.  You create an image with the "docker" or (more modern)
"podman" command, using a Dockerfile, which describes how to assemble the
image.

If you have experience with LXCs, containers are close to that.

> From: Mike
> 
> Miles Fidelman wrote:
> > Looking for a simple way to convert the vm to an image that can run as a 
> > Kubelet, and for migrating the DRBD volume to a generic block storage 
> > service.
> 
> Kubelet is part of the Kubernetes software; one doesn't run an image "as a
> kubelet", one runs it as a container.
> 
> An image typically contains just one main executable, which runs as PID 1.
> As usual, the container dies when PID 1 dies.  I suppose there may be a way
> to convert a whole domU image into an OCI image and then run the initd as
> PID 1, but that would be really weird.  So you should instead be thinking
> about decomposing your VM into an image per application.