Download the raw container linux image from CoreOS.

fetch https://stable.release.core-os.net/amd64-usr/current/coreos_production_image.bin.bz2
fetch https://stable.release.core-os.net/amd64-usr/current/coreos_production_image.bin.bz2.DIGESTS
fetch https://stable.release.core-os.net/amd64-usr/current/coreos_production_image.bin.bz2.DIGESTS.asc
fetch https://stable.release.core-os.net/amd64-usr/current/coreos_production_image.bin.bz2.DIGESTS.sig
fetch https://stable.release.core-os.net/amd64-usr/current/coreos_production_image.bin.bz2.sig

Probably good practice to Verify the image, not described here.

Optionally create a ZFS volumne for the disk drive

zfs create -V 32G -s -o reservation=none -o volmode=dev zroot/coreos

bzcat the image into your new drive, if no ZFS then simply un-bzip the file.

bzcat coreos_production_image.bin.bz2 > /dev/zvol/zroot/coreos

Optionally snapshot if you are using ZFS

zfs snap zroot/coreos@vanilla

At this point you can boot the container linux VM, but it will not be accessible.

bhyve -c 1 -m 4G -A -H -P \
  -s 0,hostbridge \
  -s 3,ahci-hd,/dev/zvol/zroot/coreos \
  -s 31,lpc \
  -l com1,stdio \
  -l bootrom,/usr/local/share/uefi-firmware/BHYVE_UEFI.fd \
  coreos

There are a couple of options here for accessing and configuring the VM:

1. Add ssh key(s) to ~core/.ssh/authorized_keys 2. Configure via hosted configuration

For both options you can boot the VM from alternate media to configure.

This example uses SystemRescueCD, I've also added a network interface so I can copy things over to the VM:

bhyve -c 1 -m 4G -A -H -P \
  -s 0,hostbridge \
  -s 2,ahci-cd,/usr/home/amarks/distfiles/systemrescuecd-x86-5.2.2.iso \
  -s 3,ahci-hd,/dev/zvol/zroot/coreos \
  -s 4,virtio-net,tap1 \
  -s 29,fbuf,w=1280,h=1024,tcp=0.0.0.0:5900 \
  -s 30,xhci,tablet \
  -s 31,lpc \
  -l com1,stdio \
  -l bootrom,/usr/local/share/uefi-firmware/BHYVE_UEFI.fd \
  coreos

From your live disk, mount the root partition

mount /dev/sda9 /media

Copy your public key(s) over to the VM and add them to ~core/.ssh/authorized_keys

Restart the VM without the live disc and ssh using public key authentication.

ssh -l core <ip address>

A web-server is required to host a configuration file. I'm using the same FreeBSD host system to host the Container Linux configuration.

pkg install nginx

Eeither write the configuration in json, or write it in a yml format then convert it to json using https://github.com/coreos/container-linux-config-transpiler.

YML:

passwd:
  users:
    - name: core
      ssh_authorized_keys:
        - "ssh-rsa AAAAB3NzaC1...

JSON:

This part is also done from the Linux Live ISO.

To add kernel parameters to instruct container Linux to use the hosted configuration, add a grub.cfg to the OEM partition of the Container Linux VM.

ls -l /dev/disk/by-partlabel

lrwxrwxrwx 1 root root 10 Aug 19 13:42 BIOS-BOOT -> ../../sda2
lrwxrwxrwx 1 root root 10 Aug 19 13:42 EFI-SYSTEM -> ../../sda1
lrwxrwxrwx 1 root root 10 Aug 19 13:42 OEM -> ../../sda6
lrwxrwxrwx 1 root root 10 Aug 19 13:43 OEM-CONFIG -> ../../sda7
lrwxrwxrwx 1 root root 10 Aug 19 13:42 ROOT -> ../../sda9
lrwxrwxrwx 1 root root 10 Aug 19 13:42 USR-A -> ../../sda3
lrwxrwxrwx 1 root root 10 Aug 19 13:42 USR-B -> ../../sda4

mount /dev/sda6 /media

/media/grub.cfg

linux_append="coreos.autologin coreos.first_boot=1 coreos.config.url=http://<IP Address>/config.json"

Container Linux specific options are documented here: https://coreos.com/os/docs/latest/booting-with-pxe.html

With your web-server running and the hosted configuration in place, reboot the VM without the Linux Live ISO.