RancherOS on digitalocean

#!/bin/bash

# get the kernel and initrd
ROS_VERSION="v0.9.2-rc4"
URL_BASE="https://github.com/rancher/os/releases/download/${ROS_VERSION}"
VMLINUX="vmlinuz-4.9.21-rancher"
INITRD="initrd-v0.9.2-rc4"

cd /tmp
echo "downloading ${URL_BASE}/${VMLINUX}" > /dev/kmsg
curl -O -L "${URL_BASE}/${VMLINUX}"
echo "downloading ${URL_BASE}/${INITRD}" > /dev/kmsg
curl -O -L "${URL_BASE}/${INITRD}"

# setup the host ready for kexec
PUBLIC_IPV4=$(wget -qO- http://169.254.169.254/metadata/v1/interfaces/public/0/ipv4/address)

if [ "$(ros config get rancher.environment.installer)" == "true" ] && ros --version &>/dev/null; then
        cat > cloud-config.yml <<EOF
#cloud-config
rancher:
  network:
    interfaces:
      eth0:
        address: $(ip -4 addr show dev eth0 | awk "/${PUBLIC_IPV4}/ {print \$2}")
        gateway: $(ip -o route get 1 | awk '{print $3}')
        dhcp: false
ssh_authorized_keys:
EOF
        while read -r KEY; do
                echo "  - ${KEY}" >> cloud-config.yml
        done < <(wget -qO- http://169.254.169.254/metadata/v1/public-keys; echo)
        yes | ros install -c cloud-config.yml -d /dev/vda --append "rancher.debug=true printk.devkmsg=on notsc clocksource=kvm-clock rancher.network.interfaces.eth0.ipv4ll rancher.cloud_init.datasources=[digitalocean] rancher.autologin=tty1 rancher.autologin=ttyS0"
        exit 0
fi

echo "apt-get installing kexec" > /dev/kmsg

export DEBIAN_FRONTEND=noninteractive
apt-get update && apt-get install -y kexec-tools ipcalc

PUBLIC_IPV4_NETMASK=$(curl -s http://169.254.169.254/metadata/v1/interfaces/public/0/ipv4/netmask)
PUBLIC_IPV4_CIDR=$(ipcalc ${PUBLIC_IPV4}/${PUBLIC_IPV4_NETMASK} | awk '/^Network/ {n=split($2, i, "/"); print i[2]};')
PUBLIC_IPV4_GATEWAY=$(curl -s http://169.254.169.254/metadata/v1/interfaces/public/0/ipv4/gateway)

echo "running kexec" > /dev/kmsg


kexec --initrd=${INITRD} -l ${VMLINUX} -f --command-line="rancher.debug=true printk.devkmsg=on notsc clocksource=kvm-clock rancher.network.interfaces.eth0.ipv4ll rancher.cloud_init.datasources=[digitalocean] rancher.autologin=tty1 rancher.autologin=ttyS0 rancher.environment.installer=true"