IMAGE postgres
LAYER shared/alpine
LAYER postgres/postgres

SCRIPT
    # Modify OS user (which will be picked up later by apk add)
    sed -i 's/postgres:x:70:70/postgres:x:5432:5432/' /etc/passwd
    sed -i 's/postgres:x:70/postgres:x:5432/' /etc/group

    # Add edge/testing repository for postgis support
    echo '@edge http://dl-cdn.alpinelinux.org/alpine/edge/testing' >>/etc/apk/repositories

    # Install PostgreSQL + PostGIS
    apk --no-cache add postgresql postgresql-contrib postgis@edge

    # Create socket directory 
    mkdir /run/postgresql
    chown postgres:postgres /run/postgresql
RUN

MOUNT /srv/postgres/data var/lib/postgresql

USER 5432 5432
CMD postgres -D /var/lib/postgresql