feat: initial docker installation support

Refs #1076

Dockerfile

@@ -0,0 +1,60 @@
+FROM phusion/baseimage:0.11
+
+CMD ["/sbin/my_init"]
+
+RUN apt-get update && apt-get -y upgrade && apt-get -y install \
+    nano \
+    rsync \
+    software-properties-common \
+    sudo \
+    wget && \
+    apt-get purge -y syslog-ng-core && \
+    apt-get clean && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
+
+ARG DOKKU_TAG=0.17.7
+ARG DOKKU_GID=200
+ARG DOKKU_UID=200
+ARG DOKKU_DOCKERFILE=true
+ARG DOKKU_WEB_CONFIG=false
+ARG DOKKU_HOSTNAME=dokku.invalid
+ARG DOKKU_VHOST_ENABLE=false
+ARG DOKKU_SKIP_KEY_FILE=true
+
+RUN addgroup --gid $DOKKU_GID dokku && \
+    adduser --uid $DOKKU_UID --gid $DOKKU_GID --disabled-password --gecos "" "dokku"
+
+RUN export DOKKU_TAG=$DOKKU_TAG \
+      DOKKU_DOCKERFILE=$DOKKU_DOCKERFILE \
+      DOKKU_WEB_CONFIG=$DOKKU_WEB_CONFIG \
+      DOKKU_HOSTNAME=$DOKKU_HOSTNAME \
+      DOKKU_VHOST_ENABLE=$DOKKU_VHOST_ENABLE \
+      DOKKU_SKIP_KEY_FILE=$DOKKU_SKIP_KEY_FILE && \
+    wget https://raw.githubusercontent.com/dokku/dokku/v$DOKKU_TAG/bootstrap.sh && \
+    bash bootstrap.sh && \
+    apt-get clean && rm -rf bootstrap.sh /var/lib/apt/lists/* /tmp/* /var/tmp/*
+
+WORKDIR /tmp
+
+COPY ./docker .
+
+RUN \
+    rsync -a /tmp/ / && \
+    rm -rf /tmp/* && \
+    rm /etc/runit/runsvdir/default/sshd/down && \
+    chown -R dokku:dokku /home/dokku/ && \
+    mkdir -p /skel/etc /skel/home /skel/var/lib/dokku /var/log/services && \
+    mv /etc/ssh /skel/etc/ssh && \
+    mv /home/dokku /skel/home/dokku && \
+    mv /var/lib/dokku/config /skel/var/lib/dokku/config && \
+    mv /var/lib/dokku/data /skel/var/lib/dokku/data && \
+    ln -sf /mount/etc/ssh /etc/ssh && \
+    ln -sf /mount/home/dokku /home/dokku && \
+    ln -sf /mount/var/lib/dokku/config /var/lib/dokku/config && \
+    ln -sf /mount/var/lib/dokku/data /var/lib/dokku/data && \
+    mv /etc/my_init.d/00_regen_ssh_host_keys.sh \
+      /etc/my_init.d/15_regen_ssh_host_keys && \
+    rm /etc/nginx/sites-enabled/default && \
+    rm /usr/share/nginx/html/index.html && \
+    rm /etc/my_init.d/10_syslog-ng.init && \
+    sed -i '/imklog/d' /etc/rsyslog.conf && \
+    rm /var/log/btmp /var/log/wtmp /var/log/*log /var/log/apt/* /var/log/dokku/* /var/log/nginx/*