docker run -it debian:jessie /bin/bash

cat >> /etc/apt/sources.list <<EOF
deb http://deb.theforeman.org/ jessie 1.10 # Replace with wheezy if on wheezy
deb http://deb.theforeman.org/ plugins 1.10
EOF

# Add the key
which curl || ( apt-get update && apt-get install -y curl )
curl http://deb.theforeman.org/pubkey.gpg | apt-key add -
apt-get update

# Ensure postgresql has the correct locale
locale -a | grep -q en_US.UTF-8 || ( echo en_US.UTF-8 UTF-8 >> /etc/locale.gen && apt-get install locales -y && locale-gen )

::shell
apt-get install foreman-installer
foreman-installer --enable-foreman-proxy --foreman-proxy-dns=true --foreman-proxy-dns-provider=powerdns --enable-foreman-proxy-plugin-dns-powerdns --foreman-proxy-plugin-dns-powerdns-manage-database=true

Run into https://github.com/theforeman/smart-proxy/pull/328