This is step by step guide for installing openSUSE MicroOS in QEMU. This can be easy to customize or automate. It may help you on other platforms too.

Installation

  1. Download the QEMU openSUSE MicroOS image.
    # curl https://download.opensuse.org/tumbleweed/appliances/openSUSE-MicroOS.x86_64-kvm-and-xen.qcow2 -o microos1.qcow2
  2. Create 10MB Combustion image:
    # dd if=/dev/zero of=combustion.img  bs=1M  count=10
# mkfs.ext4 -F combustion.img -L combustion
# mkdir /mnt/combustion
# mount combustion.img /mnt/combustion
# mkdir /mnt/combustion/combustion

    If you install on real hardware, create the file system on formated disk instead.

  3. Save Combustion script as: /mnt/combustion/combustion/script:
    #!/bin/bash
# combustion: network
# Redirect output to the console
exec > >(exec tee -a /dev/tty0) 2>&1
# Set a password for root, generate the hash with "openssl passwd -6"
echo 'root:EchlU.h2tvfOpOki54NaHpGYKwdNhjaBuSpDotD7' | chpasswd -e
# Add a public ssh key and enable sshd
mkdir -pm700 /root/.ssh/
cat id_rsa.pub >> /root/.ssh/authorized_keys
systemctl enable sshd.service
# Install vim-small
zypper --non-interactive install vim-small
# Leave a marker
echo "Configured with combustion" > /etc/issue.d/combustion
  4. Copy id_rsa.pub to the image and umount it.
  5. Create the QEMU VM:
    # virt-install --boot hd -n microos$I --os-type=Linux --os-variant=opensusetumbleweed --network network=default,mac=52:54:00:f2:fb:$I --ram=4096 --vcpus=4 --disk path=microos$I.qcow2 --noautoconsole --disk path=combustion.img,readonly=on --graphics vnc,listen=0.0.0.0,port=59$I
  6. You can undefine the combustion disk now but it is not necessary.
  7. The VM can be accessed over the SSH, by virsh console microos01 or via VNC.

Installing from the network

--location http://download.opensuse.org/tumbleweed/repo/oss/ --extra-args 'autoyast=https://pdostal.sh.cvut.cz/autoyast.xml'

We can use standard openSUSE Tumbleweed URL or path to ISO image and MicroOS AutoYAST profile (available in resources):

If you wanna boot from PXE then the kernel and initrd files are in the same location under boot/x86_64/loader/ path.

Removal

virsh destroy microos1 # Stop the VM
virsh undefine microos1 # Undefine the VM
rm microos1.qcow2 # Remove the system image

Resources:

linux