run

#!/bin/sh

if [[ "${MODE}" == "INIT" ]]; then

    echo "Intializing reroot configuration"
    
    DIFF=$(diff /app/reroot /app/per-boot/reroot > /dev/null 2>&1 )
    
    if [[ $? != 0 ]]; then      
        echo "reroot not found or does not match expected content"
        echo "creating reroot in /var/lib/cloud/scripts/per-boot"
        echo "Rebooting..."

        cp /app/reroot /app/per-boot
        chown root:root /app/per-boot/reroot
        chmod 700 /app/per-boot/reroot

        /usr/bin/nsenter -m/proc/1/ns/mnt /bin/systemctl disable docker
        /usr/bin/nsenter -m/proc/1/ns/mnt /bin/systemctl disable kubelet
        /usr/bin/nsenter -m/proc/1/ns/mnt /bin/systemctl reboot
    fi
    echo "Found reroot and content matches"
    echo "Intialization complete"
    exit 0
fi

if [[ "${MODE}" == "RUN" ]]; then

    # if we retained priviledged execution, we could make a host level
    # check to see if the system is still configuring, or in the expected
    # state of reroot, and offer liveness and readiness probes
    # but as the container runs forever, it presents a added security risk. 

    # this assumes the pod is stuck at init until docker is restarted at the
    # end of reroot script after reboot. If the container gets to this point
    # reroot must be successful and the initial state is ready. 

    echo "Reroot is already configured, sleeping forever"
    while true; do sleep 3600; done

fi

echo "Error: improper mode '${MODE}' selected"
exit 1