This is a step by step guide for installing openSUSE MicroOS within 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 your combustion script on your local computer 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 << EOF >> /root/.ssh/authorized_keys
ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQCW1AFnflfnPfKg12oAlESachI/BKlMXQ4CpAHBqrVBqlyb4bbma9fNNAlomD+qzKkorxRGIkxK/6WwIwTZpaiz84H+FlpIrPJeiz1jDeSqW+apP/trh95CvwKgCocXZQeA8O0lRy1RtPZYwKNONR427urIYTavrFcxpqeEYD/C2A+v4QdGlSJQHXsMbgZ2egFJlG7n/b0o4tJAH4YmiiKIECq7S03SHWzd8d5ZKzSxwGq35C/HBLBcgvi47jSQZC9H4eyuFY8xSb+fvi4jPXaZlbDlDaJJ9GrwgWbjyJIiwyMAhrxlaG31DmcJoMecxZ0f/ZXIDCSzSG02N93SsBH7 pavel@laptop.pdostal.cz
EOF
systemctl enable sshd.service

# Install nmap
zypper --non-interactive install nmap

# Leave a marker
echo "Configured with combustion" > /etc/issue.d/combustion
  3. If you install MicroOS on real hardware or other hypervisor, you need to create a Combustion disk image.
    # dd if=/dev/zero of=/dev/sdX  bs=1M  count=10
# mkfs.ext4 -F /dev/sdX -L combustion
# mkdir /mnt/combustion
# mount /dev/sdX /mnt/combustion
# mkdir /mnt/combustion/combustion

    Please use something like /tmp/combustion.img instead of /dev/sdX in case you install on another hypervisor.

  4. Create the QEMU VM:
    # I=01; 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$I.qcow2 --noautoconsole --graphics vnc,listen=0.0.0.0,port=59$I --qemu-commandline="-fw_cfg name=opt/org.opensuse.combustion/script,file=/var/lib/libvirt/images/combustion"
  5. The VM can be accessed over the SSH, by virsh console microos01 or via VNC.

Installing from the network via autoYAST

# virt-install -n tumbleweed --os-variant=opensusetumbleweed --network network=default,mac=52:54:00:f2:fb:67 --ram=8192 --vcpus=4 --disk path=tumbleweed.qcow2,size=40 --location http://download.opensuse.org/tumbleweed/repo/oss/ --extra-args 'autoyast=https://pdostal.sh.cvut.cz/autoyast.xml' --noautoconsole --graphics vnc,listen=0.0.0.0,port=5900

We can use the 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.

Serial console installation with UEFI and secure boot enabled

# virt-install -n tumbleweed --os-variant=opensusetumbleweed --network network=default,mac=52:54:00:f2:fb:67 --ram=8192 --vcpus=4 --disk path=tumbleweed.qcow2,size=40 --nographics --location http://download.opensuse.org/tumbleweed/repo/oss/ --extra-args "console=ttyS0,115200 textmode=1" --boot uefi,loader_secure=yes

There are two magical boot parameters: console=ttyS0,115200 which outputs the console to the serial terminal and textmode=1 which spawns the YaST in the text mode. Let’s also add --nographics as we don’t really need it.

To enable UEFI and secureboot please use the --boot uefi,loader_secure=yes parameter. With this option openSUSE can also be installed with trusted boot enabled.

Removal

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

Resources:

linux