Reverse Engineer a docker image for Dockerfile

#!/bin/bash

if [[ "$(docker images -q chenzj/dfimage:latest 2> /dev/null)" == "" ]]; then
  docker pull chenzj/dfimage
fi

read -e -p "Enter Image ID: " IMAGE_ID

if grep -q dfimage /etc/profile;
 then
 :
 else
  echo "" >> /etc/profile
  echo alias dfimage="'docker run -v /var/run/docker.sock:/var/run/docker.sock --rm chenzj/dfimage'" >> /etc/profile
  source /etc/profile
fi

docker run -v /var/run/docker.sock:/var/run/docker.sock --rm chenzj/dfimage $IMAGE_ID > Dockerfile1

docker history --no-trunc $IMAGE_ID  | tac | tr -s ' ' | cut -d " " -f 5- | sed 's,^/bin/sh -c #(nop) ,,g' | sed 's,^/bin/sh -c,RUN,g' | sed 's, && ,\n  & ,g' | sed 's,\s*[0-9]*[\.]*[0-9]*[kMG]*B\s*$,,g' | head -n -1 > Dockerfile2

Systemd Service only initiates at shutdown ( no reboot ) and keeps network intact

# the %H is the env var for systemd file which is $(hostname) for bash

[Unit]
Description=Run a Bash script at shutdown
DefaultDependencies=no
Wants=network-online.target
After=network-online.target
Before=poweroff.target halt.target

[Service]
ExecStart=/usr/bin/curl -X POST 'http://box21.ara.ac.nz:32446/query?db=telegraf' --data-urlencode "q=DROP SERIES WHERE host = '%H'"
Type=oneshot
RemainAfterExit=yes

[Install]
WantedBy=poweroff.target halt.target