bootengine: some udev rules are in rootfs but missing in initramfs

[r7vme]

Issue Report

Proper way to detect a disk in Azure was added here. Udev rules are creating symlink like /dev/disk/azure/scsi1/lun0. Unfortunately i can not use them from ignition.

Following fails with Timed out waiting for device dev-disk-azure-scsi1-lun0.device

storage:
  filesystems:
    - name: docker
      mount:
        device: /dev/disk/azure/scsi1/lun0
        format: xfs
        wipe_filesystem: true
        label: docker

Inside debug console, i see no rules for azure (which is probably expected as initramfs does not suppy them)

:/# ls /usr/lib/udev/rules.d/
10-dm.rules                  63-md-raid-arrays.rules    80-drivers.rules
13-dm-disk.rules             64-btrfs.rules             80-net-setup-link.rules
50-udev-default.rules        64-md-raid-assembly.rules  90-vconsole.rules
60-block.rules               71-seat.rules              95-dm-notify.rules
60-cdrom_id.rules            73-seat-late.rules         99-systemd.rules
60-persistent-storage.rules  75-net-description.rules

Same applies to ignition on AWS (nvme disks) i assume.

Would be really great to use ignition "filesystems" as it has many advantages over having systemd units to format and mount filesystems.

Bug

Container Linux Version

$ cat /etc/os-release
cat /etc/os-release 
NAME="Container Linux by CoreOS"
ID=coreos
VERSION=1745.7.0
VERSION_ID=1745.7.0
BUILD_ID=2018-06-14-0909
PRETTY_NAME="Container Linux by CoreOS 1745.7.0 (Rhyolite)"
ANSI_COLOR="38;5;75"
HOME_URL="https://coreos.com/"
BUG_REPORT_URL="https://issues.coreos.com"
COREOS_BOARD="amd64-usr"

Environment

Azure

Expected Behavior

Filesystem created on /dev/disk/azure/lun0

Actual Behavior

Ignition fails to boot with timeout

Reproduction Steps

1. Create Azure VM and put ignition with filesystems snippet above
2. VM will fail with provisioning timeout

Other Information

N/A

[ajeddeloh]

Whoops. Looks like we forgot to pull them into the initramfs as well. Should grab coreos/init#268 while we're at it.

[r7vme]

Label "jira" probably means that this bug is already tracked internally. :)

Do you have some rough estimates?

[lucab]

@r7vme yes, but work has not started on it yet. You'll likely see a pingback as soon as it picked up.

[r7vme]

Hi, anyhow i can help with this issue? Some high-level steps would help.

We (and i assume many others who use ignition with AWS or Azure) are waiting for this fix. Briinging back systemd units that format disks are the last thing i want to do :)

[lucab]

@r7vme at a very high level, the problem is that bootengine is not installing any of the udev-related cloud bits that are used in the real rootfs. At a low level, it means setting up proper dependencies between the ebuilds, installing those bits via a dracut module, and testing the result in azure.

I haven't personally looked into this so I don't know if this was simply completely overlooked or if it is done somewhere already and just some bits are missing.