image_to_vm: add support for hyperv_vhdx format

[ader1990]

Add support for Gen 2 Hyper-V VMs.

See: flatcar/Flatcar#1009

./image_to_vm tool has now a new supported format: hyperv_vhdx, that produces .vhdx dynamic disks.

How to use

 ./image_to_vm.sh --from ../build/images/amd64-usr/developer-latest/ --format hyperv_vhdx

Testing done

[Describe the testing you have done before submitting this PR. Please include both the commands you issued as well as the output you got.]

• Changelog entries added in the respective changelog/ directory (user-facing change, bug fix, security fix, update)
• Inspected CI output for image differences: /boot and /usr size, packages, list files for any missing binaries, kernel modules, config files, kernel modules, etc.

[jepio]

Images have been produced: https://bincache.flatcar-linux.net/images/amd64/3916.0.0+vhdx/.

I don't like that the images end up being called flatcar_production_hyperv_vhdx_image.vhdx.bz2 (double vhdx).

[github-actions]

Build action triggered: https://github.com/flatcar/scripts/actions/runs/8564352706

[ader1990]

Images have been produced: https://bincache.flatcar-linux.net/images/amd64/3916.0.0+vhdx/.

I don't like that the images end up being called flatcar_production_hyperv_vhdx_image.vhdx.bz2 (double vhdx).

It is the same naming convention for rackspace and cloudstack. Adding gen2 in the naming would be wrong, and only multiplexing the hyperv image format to create two images .vhd and .vhdx would make sense, but then, it will break the convention I saw in the current implementation, to create only one image file per format.

[ader1990]

Images have been produced: https://bincache.flatcar-linux.net/images/amd64/3916.0.0+vhdx/.

I don't like that the images end up being called flatcar_production_hyperv_vhdx_image.vhdx.bz2 (double vhdx).

@jepio I tested the image on a gen 2 vm, and the image does not properly boot with the initrd stage error: hv_utils kernel module not found. Investigation required.

[ader1990]

Images have been produced: https://bincache.flatcar-linux.net/images/amd64/3916.0.0+vhdx/.
I don't like that the images end up being called flatcar_production_hyperv_vhdx_image.vhdx.bz2 (double vhdx).

@jepio I tested the image on a gen 2 vm, and the image does not properly boot with the initrd stage error: hv_utils kernel module not found. Investigation required.

Code is failing here: https://github.com/coreos/ignition/blob/v2.18.0/internal/providers/hyperv/kvp.go#L50.
Flatcar kernel is built with hv_utils kernel module, but the module is not present in the /lib/module. Do you know why this happens?

@jepio @pothos

[ader1990]

Images have been produced: https://bincache.flatcar-linux.net/images/amd64/3916.0.0+vhdx/.
I don't like that the images end up being called flatcar_production_hyperv_vhdx_image.vhdx.bz2 (double vhdx).

@jepio I tested the image on a gen 2 vm, and the image does not properly boot with the initrd stage error: hv_utils kernel module not found. Investigation required.

Code is failing here: https://github.com/coreos/ignition/blob/v2.18.0/internal/providers/hyperv/kvp.go#L50. Flatcar kernel is built with hv_utils kernel module, but the module is not present in the /lib/module. Do you know why this happens?

@jepio @pothos

Okay, I think I know why, because we are not using the upstream initrd generation for ignition, https://github.com/coreos/ignition/blob/d304850c3d3696822bc05e0833ee4b27df9d7a38/dracut/30ignition/module-setup.sh.

This PR requires a bootengine PR to add that module.

[ader1990]

Test results look good, bootengine PR was merged with commit id updated, changelog was added.

[ader1990]

Note that the VHDX image file after decompression has 1.1GB in file size.

[ader1990]

Bootengine commit was removed, as the flatcar/scripts main is already using the newest bootengine HEAD.

[pothos]

Bootengine commit was removed, as the flatcar/scripts main is already using the newest bootengine HEAD.

Almost^^ I had to push a fix as it was the repo's HEAD.

[ader1990]

Bootengine commit was removed, as the flatcar/scripts main is already using the newest bootengine HEAD.

Almost^^ I had to push a fix as it was the repo's HEAD.

I ll have to rebase on f04ba66, thought the commit was already in at that moment.

[pothos]

A new build is running (.11) and should show up under https://bincache.flatcar-linux.net/images/amd64/9999.9.11+ader1990-hyperv-vhdx-support/