[SOLVED] Cloud-init breaking grub-pc boot disk selection?

[czechsys]

Hi,

i have debian 11 VM as golden image. I have boot disk set as /dev/sda. VM shutdown, cloud-init disk regenerated.

Disk /dev/sda:

Disk /dev/sda: 10 GiB, 10737418240 bytes, 20971520 sectors
Disk model: QEMU HARDDISK   
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xb75887e2

Device     Boot Start      End  Sectors Size Id Type
/dev/sda1  *     2048 20969471 20967424  10G 8e Linux LVM


Disk /dev/mapper/vg0-root: 7.45 GiB, 7998537728 bytes, 15622144 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/mapper/vg0-swap: 2.55 GiB, 2734686208 bytes, 5341184 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

Clone the new VM:
1] without cloud-init:

debconf-show grub-pc

grub-pc/install_devices: /dev/disk/by-id/scsi-0QEMU_QEMU_HARDDISK_drive-scsi0

2] with cloud-init:

debconf-show grub pc

grub-pc/install_devices: /dev/disk/by-id/dm-name-vg0-root

The 2] is generating same problem as https://ubuntuforums.org/showthread.php?t=2408085 , dunno if problem is grub-pc directly or cloud-init. My ansible is failing due this. How to solve it?

 

[mira]

How is cloud-init configured inside the guest? /etc/cloud/cloud.cfg
Please also provide the VM config qm config <VMID>.

Does it boot fine and is it just Ansible that fails once it is booted, or where exactly does it fail?

 

[czechsys]

boot: cdn
bootdisk: scsi0
cores: 2
cpu: host
ide0: vg-iscsi:vm-103-cloudinit,media=cdrom,size=4M
ide2: none,media=cdrom
memory: 4096
name: testcloud
net0: virtio=06:55:57:66:58:E1,bridge=vmbr0,link_down=1
net1: virtio=2A:4C:E8:43:F6:BF,bridge=vmbr0,link_down=1,tag=VLANID
numa: 0
ostype: l26
protection: 1
scsi0: vg-iscsi:vm-103-disk-0,discard=on,size=10G
scsihw: virtio-scsi-pci
smbios1: uuid=eda53093-210d-4780-aade-f6c75331c3a7
sockets: 1

/etc/cloud/cloud.cfg from cloned and booted VM:

# The top level settings are used as module
# and system configuration.

# A set of users which may be applied and/or used by various modules
# when a 'default' entry is found it will reference the 'default_user'
# from the distro configuration specified below
users:
   - default

# If this is set, 'root' will not be able to ssh in and they 
# will get a message to login instead as the above $user (debian)
disable_root: true

# This will cause the set+update hostname module to not operate (if true)
preserve_hostname: false

# This prevents cloud-init from rewriting apt's sources.list file,
# which has been a source of surprise.
apt_preserve_sources_list: true

# Example datasource config
# datasource: 
#    Ec2: 
#      metadata_urls: [ 'blah.com' ]
#      timeout: 5 # (defaults to 50 seconds)
#      max_wait: 10 # (defaults to 120 seconds)

# The modules that run in the 'init' stage
cloud_init_modules:
 - migrator
 - seed_random
 - bootcmd
 - write-files
 - growpart
 - resizefs
 - disk_setup
 - mounts
 - set_hostname
 - update_hostname
 - update_etc_hosts
 - ca-certs
 - rsyslog
 - users-groups
 - ssh

# The modules that run in the 'config' stage
cloud_config_modules:
# Emit the cloud config ready event
# this can be used by upstart jobs for 'start on cloud-config'.
 - emit_upstart
 - ssh-import-id
 - locale
 - set-passwords
 - grub-dpkg
 - apt-pipelining
 - apt-configure
 - ntp
 - timezone
 - disable-ec2-metadata
 - runcmd
 - byobu

# The modules that run in the 'final' stage
cloud_final_modules:
 - package-update-upgrade-install
 - fan
 - puppet
 - chef
 - salt-minion
 - mcollective
 - rightscale_userdata
 - scripts-vendor
 - scripts-per-once
 - scripts-per-boot
 - scripts-per-instance
 - scripts-user
 - ssh-authkey-fingerprints
 - keys-to-console
 - phone-home
 - final-message
 - power-state-change

# System and/or distro specific settings
# (not accessible to handlers/transforms)
system_info:
   # This will affect which distro class gets used
   distro: debian
   # Default user name + that default users groups (if added/used)
   default_user:
     name: debian
     lock_passwd: True
     gecos: Debian
     groups: [adm, audio, cdrom, dialout, dip, floppy, netdev, plugdev, sudo, video]
     sudo: ["ALL=(ALL) NOPASSWD:ALL"]
     shell: /bin/bash
   # Other config here will be given to the distro class and/or path classes
   paths:
      cloud_dir: /var/lib/cloud/
      templates_dir: /etc/cloud/templates/
      upstart_dir: /etc/init/
   package_mirrors:
     - arches: [default]
       failsafe:
         primary: http://deb.debian.org/debian
         security: http://security.debian.org/
   ssh_svcname: ssh

I think i have cloud-init pure default, just setting IP in GUI to be accessible via ansible after boot. VM boots fine, ansible fails on every operation via apt when grub(-pc) is reconfigured.

 

[mira]

Looks fine here. Can you provide your ansible playbook and the exact error you get, including the step that lead to it?

 

[czechsys]

Ansible is calling apt modules (https://docs.ansible.com/ansible/latest/collections/ansible/builtin/apt_module.html ) for update installed packages. The problem isn't tied to ansible, it shows even on manual update.

 

[mira]

So this seems to be coming from the following module that's enabled in your cloud.cfg: https://cloudinit.readthedocs.io/en/latest/reference/modules.html#grub-dpkg

Do you need this for your use case or can you disable it? It should be run once per instance, but since you clone from a template, the template should have it configured already.

 

[czechsys]

I can disable it so i will look into it.