Dockerfile for network booting ARM64 machines

Dockerfile

FROM ubuntu:xenial
ENV ARCH arm64
ENV DIST xenial
ENV MIRROR http://ports.ubuntu.com
RUN apt-get -q update
RUN apt-get -qy install dnsmasq iptables curl
RUN curl -o /pipework https://raw.githubusercontent.com/jpetazzo/pipework/master/pipework
RUN chmod +x pipework
RUN mkdir /tftp
WORKDIR /tftp
RUN curl -o /tmp/netboot.tar.gz $MIRROR/ubuntu-ports/dists/xenial/main/installer-arm64/current/images/netboot/netboot.tar.gz
RUN tar zxf /tmp/netboot.tar.gz -C /tftp
CMD \
    echo Setting up iptables... &&\
    iptables -t nat -A POSTROUTING -j MASQUERADE &&\
    echo Waiting for pipework to give us the eth1 interface... &&\
    /pipework --wait &&\
    myIP=$(ip addr show dev eth1 | awk -F '[ /]+' '/global/ {print $3}') &&\
    mySUBNET=$(echo $myIP | cut -d '.' -f 1,2,3) &&\
    echo Starting DHCP+TFTP server...&&\
    dnsmasq --interface=eth1 \
            --dhcp-range=$mySUBNET.101,$mySUBNET.199,255.255.255.0,1h \
            --dhcp-boot=ubuntu-installer/arm64/bootnetaa64.efi \
            --enable-tftp --tftp-root=/tftp/ --no-daemon

Based on https://jpetazzo.github.io/2013/12/07/pxe-netboot-docker/