#!/usr/bin/env bash

 #
 # Create a base CentOS Docker image.
 #
 # This script is useful on systems with yum installed (e.g., building
 # a CentOS image on CentOS).  See contrib/mkimage-rinse.sh for a way
 # to build CentOS images on other systems.
 

 set -e
 

 usage() {
     cat <<EOOPTS
 $(basename $0) [OPTIONS] <name>
 OPTIONS:

   -p "<packages>"  The list of packages to install in the container.
                    The default is blank.
   -g "<groups>"    The groups of packages to install in the container.
                    The default is "Core".
   -y <yumconf>     The path to the yum config to install packages from. The
                    default is /etc/yum.conf for Centos/RHEL and /etc/dnf/dnf.conf for Fedora

 EOOPTS
     exit 1
 }
 
 # option defaults
 yum_config=/etc/yum.conf

 if [ -f /etc/dnf/dnf.conf ] && command -v dnf &> /dev/null; then
 	yum_config=/etc/dnf/dnf.conf
 	alias yum=dnf

 fi
 install_groups="Core"
 while getopts ":y:p:g:h" opt; do

     case $opt in
         y)
             yum_config=$OPTARG
             ;;
         h)
             usage
             ;;

         p)
             install_packages="$OPTARG"
             ;;
         g)
             install_groups="$OPTARG"
             ;;

         \?)
             echo "Invalid option: -$OPTARG"
             usage
             ;;
     esac
 done
 shift $((OPTIND - 1))
 name=$1
 
 if [[ -z $name ]]; then
     usage
 fi
 
 target=$(mktemp -d --tmpdir $(basename $0).XXXXXX)
 
 set -x
 

 mkdir -m 755 "$target"/dev

 mknod -m 600 "$target"/dev/console c 5 1
 mknod -m 600 "$target"/dev/initctl p
 mknod -m 666 "$target"/dev/full c 1 7
 mknod -m 666 "$target"/dev/null c 1 3
 mknod -m 666 "$target"/dev/ptmx c 5 2
 mknod -m 666 "$target"/dev/random c 1 8
 mknod -m 666 "$target"/dev/tty c 5 0
 mknod -m 666 "$target"/dev/tty0 c 4 0
 mknod -m 666 "$target"/dev/urandom c 1 9
 mknod -m 666 "$target"/dev/zero c 1 5

 # amazon linux yum will fail without vars set
 if [ -d /etc/yum/vars ]; then
 	mkdir -p -m 755 "$target"/etc/yum
 	cp -a /etc/yum/vars "$target"/etc/yum/
 fi
 

 if [[ -n "$install_groups" ]];
 then
     yum -c "$yum_config" --installroot="$target" --releasever=/ --setopt=tsflags=nodocs \

         --setopt=group_package_types=mandatory -y groupinstall "$install_groups"

 fi
 
 if [[ -n "$install_packages" ]];
 then
     yum -c "$yum_config" --installroot="$target" --releasever=/ --setopt=tsflags=nodocs \

         --setopt=group_package_types=mandatory -y install "$install_packages"

 fi
 

 yum -c "$yum_config" --installroot="$target" -y clean all

 
 cat > "$target"/etc/sysconfig/network <<EOF
 NETWORKING=yes
 HOSTNAME=localhost.localdomain
 EOF
 

 # effectively: febootstrap-minimize --keep-zoneinfo --keep-rpmdb --keep-services "$target".

 #  locales
 rm -rf "$target"/usr/{{lib,share}/locale,{lib,lib64}/gconv,bin/localedef,sbin/build-locale-archive}

 #  docs and man pages

 rm -rf "$target"/usr/share/{man,doc,info,gnome/help}
 #  cracklib
 rm -rf "$target"/usr/share/cracklib
 #  i18n
 rm -rf "$target"/usr/share/i18n

 #  yum cache
 rm -rf "$target"/var/cache/yum
 mkdir -p --mode=0755 "$target"/var/cache/yum

 #  sln
 rm -rf "$target"/sbin/sln
 #  ldconfig

 rm -rf "$target"/etc/ld.so.cache "$target"/var/cache/ldconfig
 mkdir -p --mode=0755 "$target"/var/cache/ldconfig

 
 version=

 for file in "$target"/etc/{redhat,system}-release
 do
     if [ -r "$file" ]; then
         version="$(sed 's/^[^0-9\]*\([0-9.]\+\).*$/\1/' "$file")"
         break
     fi
 done

 
 if [ -z "$version" ]; then
     echo >&2 "warning: cannot autodetect OS version, using '$name' as tag"
     version=$name
 fi
 
 tar --numeric-owner -c -C "$target" . | docker import - $name:$version

 docker run -i -t --rm $name:$version /bin/bash -c 'echo success'

 
 rm -rf "$target"