Copying in pre-existing image recipes.

+FROM debian:stretch-slim
+
+COPY files/ /tmp/files
+RUN /tmp/files/configure
+EXPOSE 143
+VOLUME ["/home"]
+ENTRYPOINT ["/sbin/entrypoint"]
+CMD ["/usr/sbin/dovecot", "-F"]
+

+#!/bin/sh
+
+set -e
+
+mkdir -p /etc/dovecot/conf.d/
+cp /tmp/files/dovecot.conf /etc/dovecot/conf.d/99-docker.conf
+
+apt-get update
+apt-get install -y ssmtp dovecot-sqlite dovecot-imapd
+
+cp /tmp/files/entrypoint /sbin/entrypoint
+
+addgroup hostgroup
+adduser --gecos 'Host User' --ingroup hostgroup --disabled-password hostuser

+mail_location = maildir:~/Maildir
+disable_plaintext_auth = no

+#!/bin/bash
+
+set -ex
+
+hostuser_home="$(getent passwd hostuser | cut -f 6 -d :)"
+
+if [[ $GID ]]; then
+	old_gid=$(getent group hostgroup | cut -f 3 -d :)
+	groupmod -g $GID hostgroup
+	find "$hostuser_home" -gid $old_gid -print0 | xargs -0r chgrp hostgroup
+fi
+if [[ $UID ]]; then
+	usermod -u $UID hostuser
+fi
+
+if [[ $DOVECOT_HOSTUSER_PASSWORD ]]; then
+	echo "hostuser:$DOVECOT_HOSTUSER_PASSWORD" | chpasswd
+fi
+
+exec "$@"

+FROM debian:stretch
+
+COPY files/ /tmp/files/
+RUN /tmp/files/configure
+
+ENTRYPOINT ["/sbin/entrypoint.sh"]
+CMD ["nginx", "-g", "daemon off;"]

+#!/bin/sh
+
+set -e
+apt-get update
+apt-get install -y ssmtp nginx libnginx-mod-http-subs-filter
+rm /etc/nginx/sites-enabled/default
+cp -a /tmp/files/entrypoint.sh /sbin

+#!/bin/sh
+
+set -e
+
+if [ "$NGINX_CONF_NAME" ]; then
+	ln -sf "../sites-available/$NGINX_CONF_NAME.conf" /etc/nginx/sites-enabled/app.conf
+fi
+
+exec "$@"

+FROM node
+
+COPY files/ /tmp/files/
+RUN /tmp/files/configure
+
+#ADD https://raw.githubusercontent.com/wp-cli/builds/gh-pages/phar/wp-cli.phar /usr/local/bin/wp
+#RUN ["chmod", "755", "/usr/local/bin/wp"]
+
+ENTRYPOINT ["/root/entrypoint"]
+#CMD ["/usr/sbin/php5-fpm", "--nodaemonize", "--force-stderr", "--fpm-config", "/etc/php5/fpm/php-fpm.conf"]

+#!/bin/sh
+
+set -e
+apt-get update
+apt-get install -y ssmtp sudo
+#npm install -g gulp grunt
+
+cp /tmp/files/entrypoint /root/entrypoint

+#!/bin/bash
+
+set -ex
+
+node_home="$(getent passwd node | cut -f 6 -d :)"
+
+if [[ $GID ]]; then
+	old_gid=$(getent group node | cut -f 3 -d :)
+	groupmod -g $GID node
+	find "$node_home" -gid $old_gid -print0 | xargs -0r chgrp node
+fi
+if [[ $UID ]]; then
+	usermod -u $UID node
+fi
+if [[ -e package.json ]]; then
+	sudo -u node npm install
+fi
+exec "$@"

+FROM debian:stretch
+
+COPY files/ /tmp/files/
+RUN /tmp/files/configure
+
+ADD https://raw.githubusercontent.com/wp-cli/builds/gh-pages/phar/wp-cli.phar /usr/local/bin/wp
+RUN ["chmod", "755", "/usr/local/bin/wp"]
+
+ENTRYPOINT ["/root/entrypoint"]
+CMD ["/usr/sbin/php-fpm7.0", "--nodaemonize", "--force-stderr", "--fpm-config", "/etc/php/7.0/fpm/php-fpm.conf"]

+#!/bin/sh
+
+set -e
+cp /tmp/files/default-release.conf /etc/apt/apt.conf.d/default-release
+apt-get update
+apt-get install -y ssmtp php7.0-fpm php7.0-mysql php7.0-imagick php7.0-ldap php7.0-xml php7.0-mbstring php7.0-mcrypt php7.0-gd php7.0-apc git ffmpeg ghostscript
+
+rm /etc/php/7.0/fpm/pool.d/www.conf
+cp -a /tmp/files/app-defaults.conf /etc/php/7.0/fpm
+
+cp /tmp/files/entrypoint /root/entrypoint
+
+addgroup hostgroup
+adduser --gecos 'Host User' --ingroup hostgroup --disabled-password hostuser
+su - hostuser -c 'git config --global user.email hostuser@php-fpm'
+su - hostuser -c 'git config --global user.name "Host User"'

+APT::Default-Release "stretch";

+#!/bin/bash
+
+set -ex
+
+hostuser_home="$(getent passwd hostuser | cut -f 6 -d :)"
+
+if [[ $GID ]]; then
+	old_gid=$(getent group hostgroup | cut -f 3 -d :)
+	groupmod -g $GID hostgroup
+	find "$hostuser_home" -gid $old_gid -print0 | xargs -0r chgrp hostgroup
+fi
+if [[ $UID ]]; then
+	usermod -u $UID hostuser
+fi
+mkdir -p /run/php
+
+update_sapi_conf() {
+	declare sapi="$1" file
+	shift
+	find "/etc/php/7.0/$sapi/conf.d" -name '97-app-*' -delete
+	for file in /etc/php/7.0/app.conf.d/*; do
+		if [[ -r $file ]]; then
+			ln -sf "$file" "/etc/php/7.0/$sapi/conf.d/97-app-${file##*/}"
+		fi
+	done
+}
+update_sapi_conf fpm
+
+exec "$@"

+deb http://ftp.us.debian.org/debian/ stretch main contrib non-free

+FROM debian:stretch-slim
+
+COPY files/ /tmp/files
+RUN /tmp/files/configure
+EXPOSE 25
+VOLUME ["/home"]
+ENTRYPOINT ["/sbin/entrypoint"]
+CMD ["/usr/lib/postfix/sbin/master", "-d"]
+

+#!/bin/sh
+
+set -e
+
+apt-get update
+apt-get install -y bsd-mailx postfix rsyslog
+
+cp /tmp/files/rsyslog-stderr.conf /etc/rsyslog.d
+cp /tmp/files/entrypoint /sbin/entrypoint
+
+addgroup hostgroup
+adduser --gecos 'Host User' --ingroup hostgroup --disabled-password hostuser

+#!/bin/bash
+
+set -ex
+
+hostuser_home="$(getent passwd hostuser | cut -f 6 -d :)"
+
+if [[ $GID ]]; then
+	old_gid=$(getent group hostgroup | cut -f 3 -d :)
+	groupmod -g $GID hostgroup
+	find "$hostuser_home" -gid $old_gid -print0 | xargs -0r chgrp hostgroup
+fi
+if [[ $UID ]]; then
+	usermod -u $UID hostuser
+fi
+
+HOSTNAME=$(hostname -f)
+
+postconf -e \
+	"myhostname = ${POSTFIX_MAILNAME:-$HOSTNAME}" \
+	"myorigin = app" \
+	"mydestination = $HOSTNAME, localhost.localdomain, localhost, app" \
+	"mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128 10.0.0.0/8 172.0.0.0/8 192.168.0.0/16"\
+	"inet_protocols = all" \
+	"relayhost = $POSTFIX_RELAYHOST" \
+	"virtual_maps = hash:/etc/postfix/virtual, regexp:/etc/postfix/virtual-regexp" \
+	"home_mailbox = Maildir/" \
+	&& true
+
+: > /etc/postfix/virtual
+postmap /etc/postfix/virtual
+
+: ${POSTFIX_FORWARD_APP:=hostuser+app@localhost}
+: ${POSTFIX_FORWARD_CATCHALL:=hostuser+catchall@localhost}
+
+POSTFIX_FORWARD_APP_quoted="$(echo "$POSTFIX_FORWARD_APP" | sed 's/\([][\\+*.$^()]\)/\\\1/g')"
+POSTFIX_FORWARD_CATCHALL_quoted="$(echo "$POSTFIX_FORWARD_CATCHALL" | sed 's/\([][\\+*.$^()]\)/\\\1/g')"
+(
+	echo "/.+@app/ $POSTFIX_FORWARD_APP"
+	if [[ $POSTFIX_CATCHALL ]]; then
+		echo "if !/^($POSTFIX_FORWARD_APP_quoted|$POSTFIX_FORWARD_CATCHALL_quoted)/"
+		echo "/.+@.+/ $POSTFIX_FORWARD_CATCHALL"
+		echo "endif"
+	fi
+) > /etc/postfix/virtual-regexp
+
+cp /etc/resolv.conf /etc/services /var/spool/postfix/etc
+
+/etc/init.d/rsyslog start
+exec "$@"

+*.*	/proc/1/fd/2

+FROM debian:stretch-slim
+
+COPY files/ /tmp/files
+RUN /tmp/files/configure
+EXPOSE 80
+#VOLUME ["/home"]
+ENTRYPOINT ["/sbin/entrypoint"]
+CMD ["/usr/sbin/apache2", "-D", "NO_DETACH"]
+

+Alias / /var/lib/roundcube/

+#!/bin/sh
+
+set -e
+
+export DEBIAN_FRONTEND=noninteractive
+
+apt-get update
+apt-get install -y ssmtp roundcube-sqlite3 roundcube roundcube-plugins
+
+sed -i "/default_host/c\$config['default_host'] = 'imap';" /etc/roundcube/config.inc.php
+sed -i "/smtp_server/c\$config['smtp_server'] = 'smtp';" /etc/roundcube/config.inc.php
+
+for plugin in jqueryui zipdownload; do
+	cp -a /var/lib/roundcube/plugins/$plugin/config.inc.php.dist /etc/roundcube/plugins/$plugin
+done
+
+cp /tmp/files/apache-mail-container.conf /etc/apache2/conf-enabled
+
+cp /tmp/files/entrypoint /sbin/entrypoint
+
+addgroup hostgroup
+adduser --gecos 'Host User' --ingroup hostgroup --disabled-password hostuser

+#!/bin/bash
+
+set -ex
+
+hostuser_home="$(getent passwd hostuser | cut -f 6 -d :)"
+
+if [[ $GID ]]; then
+	old_gid=$(getent group hostgroup | cut -f 3 -d :)
+	groupmod -g $GID hostgroup
+	find "$hostuser_home" -gid $old_gid -print0 | xargs -0r chgrp hostgroup
+fi
+if [[ $UID ]]; then
+	usermod -u $UID hostuser
+fi
+
+. /etc/apache2/envvars
+
+exec "$@"