Support userdata on QEMU PPC64

[bgilbert]

Feature Request

Environment

QEMU ppc64

Desired Feature

Support reading an Ignition config from userdata. fw_cfg is not supported on ppc64.

Other Information

SMBIOS OEM strings are also not supported; see #656 (comment).

[bgilbert]

Ideally QEMU and libvirt would gain support for a generic userdata mechanism that works on all CPU architectures; see #656 (comment).

[jcajka]

Could we in the mean time drop the hard requirement on the qemu_fw_cfg as it break the coreos assembler on platforms that are not supported by it. And from my understanding it is not only way how to interact with ignition, right?

[dustymabe]

Could we in the mean time drop the hard requirement on the qemu_fw_cfg as it break the coreos assembler on platforms that are not supported by it.

What specific error are you seeing?

And from my understanding it is not only way how to interact with ignition, right?

It is on the qemu (local qemu/libvirt) platform.

I didn't realize you had said only way

[jcajka]

@dustymabe respective kernel module doesn't exists on those platforms so dracut during initramfs always errorout
To clarify my drop has been directed in direction of dropping the requirement on not supported arches(this could be done even on spec file level).

[dustymabe]

could you try to provide ignition.config.url=http://example.com/ignition.ign on the kernel command line and see if it still errors out?

[jcajka]

It is at build time of artifacts.

[ajeddeloh]

Ignition itself doesn't require it for building, only at runtime. I'm guessing this is erroring out when rpm-ostree runs dracut and tries to install the kernel module to the initramfs?

[jcajka]

@ajeddeloh yes, that is the case

[jcajka]

Do you prefer some change to this repo or just "per package" patch in the spec?

[dustymabe]

right I was thinking it was probably ignition-dracut.. so we would make the change there:

https://github.com/coreos/ignition-dracut/blob/master/dracut/30ignition/module-setup.sh#L78

Can we do arch specific things in dracut modules ?

[ajeddeloh]

There's not a lot to change in this repo other than adding the ability to exclude platforms from the build process. I'm fine with building Ignition with qemu support that doesn't work on some arches short term. But long term we need to fix it or have a way to disable platforms at compile time. I suppose we could have a patch applied to the spec file that removes qemu support on unsupported platforms, but that seems hacky; it'd be better to make the ignition build process more modular.

The changes would probably need to be made around here: https://github.com/coreos/ignition-dracut/blob/master/dracut/30ignition/module-setup.sh#L78 but I'm not sure what the normal approach for specifying different behavior with different arches for dracut is.

[dustymabe]

i guess dracut is just bash scripts so can probably just uname -i and act differently based on that.

[jcajka]

@ajeddeloh tbh me neither. I will dig in to the possibility to do it "cleanly" in dracut, otherwise IMHO some ifarch patch will be good for the mean time.

[jlebon]

@jaypoulz @Prashanth684 Has a channel for PPC64 been investigated and discussed?

[Prashanth684]

@jaypoulz @Prashanth684 Has a channel for PPC64 been investigated and discussed?

No. it has been a more urgent requirement for s390x, becauseOpenshft libvirt IPI was the only way possible for running the CI. For ppc64, we have the Openstack platform for running the CI, so in terms of priority it has taken a backseat.