dockerflatten

#!/bin/bash 
#
#--------------------------------------
# Flatten docker image optimising space
# (C) M.A. O'Neill, Tumbling Dice 2021
#--------------------------------------
#---------------
# Display banner
#---------------

echo ""
echo "    dockerflatten version 2.00"
echo "    (C) M.A. O'Neill, Tumbling Dice, 2021"
echo ""


#---------------------
# Is docker installed?
#---------------------

docker_installed= $(which dockerd |& grep "no")
if [ "$docker_installed" != "" ] ; then
        echo
        echo "    dockerflatten ERROR: docker is not installed on this host"
        echo

        exit 255 
fi


#--------------------
# Is dockerd running?
#--------------------

dockerd_running=$(docker info |& head -1 |& awk '{print $1}' |& grep "Cannot")
if [ "$dockerd_running" != "" ] ; then
        echo
        echo "    dockerflatten ERROR: dockerd is not running on this host"
        echo

        exit 255 
fi


#-------------------------------------------------
# Get docker parameters (for flattening operation)
#-------------------------------------------------

echo ""
docker images
echo ""


docker_repository=$(ask "    docker repository name")
if [ "$docker_repository" = "" ] ; then
	docker_repository="centos-ssh-dev"
	echo "    dockerflatten WARNING: using default docker repository: '$docker_repository'"
	echo ""
elif [ "$docker_repository" = "q" ] || [ "$docker_repository" = "quit" ] ; then
        exit 1 
fi


docker_image=$(ask "    docker image name")
if [ "$docker_image" = "" ] ; then
	echo "    dockerflatten ERROR: expecting docker image name"
	exit 255 
elif [ "$docker_image" = "q" ] || [ "$docker_image" = "quit" ] ; then
        exit 1
fi


docker_container=$(ask "    docker container name")
if [ "$docker_image" = "" ] ; then
	echo "    dockerflatten ERROR: expecting docker container name"
	exit 255 
elif [ "$docker_container" == "q" ] || [ "$docker_container" = "quit" ] ; then
        exit 255 

fi


echo ""
echo "    flattening container $docker_container and saving it to ${docker_repository}:${docker_image}"
echo ""

docker export $docker_container | docker import - "$docker_repository:$docker_image"

echo ""
echo "    finished"
echo ""

exit 0