[ovirt-devel] oVirt Node Next upgrades

[Fabian Deutsch]

Hey,

in the last few weeks the Node team made some significant steps on oVirt Node
Next.

In a nutshell, Node can now be installed using an ISO, added to Engine
and upgraded using `yum update`. This is nice.

To achieve this goal a few smaller steps were needed:

Layout initialization
---------------------
Now the LVM specific layout is initialized during installation. This required
some patches on imgbased.
With those patches, imgbased also gained a bit of a refactoring.

Bootloader configuration
------------------------
Switching between the images works by booting into the different images.
To enable this, bootloader entries are needed.
Previously there was a quick-n-dirty BLS based implementation, now `grubby`
is used to modify the bootloader
This is more aligned with how bootloader configuration is recommended on
CentOS/Fedora and RHEL.
And in addition it was easy to implement.

RPM dependencies
----------------
To get `yum update` working propperly we had to work out a mechanism to
update an image without an image. What!? Well, it's a long story, read all of
it here:
http://www.ovirt.org/node/4.0/update/

Installation ISO generation
---------------------------
This is not really a necessary thing, but it seems that it really helps to
install the initial image of Node Next.
And because our delivery format is so nice, it was very simple to provide this
installation ISO.
Read more about it here:
http://dummdida.tumblr.com/post/139903469765/ovirt-node-next-installation-iso


That's quite a step which we made in the last few weeks, but more is to come.


oVirt 3.6
---------
We noticed that Node is using the rpms from the oVirt master branches, which
makes it a bit unstable. We plan to switch to consume oVirt 3.6 rpms.

Cockpit
-------
Node will have a cockpit plugin for oVirt stuff, this work needs to be started.

Rollback
--------
Rollback is simple in Node, just boot the older image. We want to add a verb to
allow a user to trigger the rollback from the terminal.


It's time to give oVirt Node Next a try! Feel free to provide us some
feedback on
how it went.

On behalf of the Node team
- fabian