Has the armhf cross compilation repositories been removed?

Thanks! After some digging, I realise we need to patch the sources.list to include ports

    FROM ubuntu
    USER root
    RUN sed -i "s/^deb /deb \[arch=$(dpkg --print-architecture)] /" /etc/apt/sources.list
    RUN for SUFFIX in "" "-updates" "-security"; do \
      echo "deb [arch=armhf] http://ports.ubuntu.com/ubuntu-ports/ xenial${SUFFIX} main restricted universe multiverse" \
      >> /etc/apt/sources.list.d/armhf.list; \
    done
    RUN dpkg --add-architecture armhf
    RUN apt-get update

Note that I'm not quite sure of the origins of this script.