IMAGE build
LAYER shared/alpine3.8
COPY https://github.com/gliderlabs/docker-alpine/raw/rootfs/library-3.8/x86_64/versions/library-3.8/x86_64/rootfs.tar.xz

RUN EOF
    # Add edge/testing repository
    echo '@em http://dl-cdn.alpinelinux.org/alpine/edge/main' >>/etc/apk/repositories
    echo '@et http://dl-cdn.alpinelinux.org/alpine/edge/testing' >>/etc/apk/repositories
    echo '@ec http://dl-cdn.alpinelinux.org/alpine/edge/community' >>/etc/apk/repositories

    # Update packages
    apk --no-cache upgrade

    # Install s6 supervisor
    apk --no-cache add libxml2 libxslt s6@em
EOF