.bin/custom-chroot

   1 #!/bin/bash -e
   2
   3 [[ -w / ]] || exec sudo env HOME="$HOME" "$0" "$@"
   4
   5 if [[ -z ${UNSHARE} ]] ; then
   6         mount_args=
   7         if type -P unshare >&/dev/null ; then
   8                 UNSHARE=true exec unshare -m -- "$0" "$@"
   9         fi
  10 else
  11         mount_args='-n'
  12 fi
  13 unset UNSHARE
  14
  15 mounts="proc sys dev dev/pts usr/portage usr/portage/distfiles"
  16
  17 chroot=${0%/*}
  18 case ${chroot} in
  19         .) chroot=${PWD} ;;
  20         ./*) chroot=${PWD}/${chroot#./} ;;
  21 esac
  22 cd "${chroot}"
  23
  24 do_umount() {
  25         mounts=$(mount | grep ${chroot} | awk '{print $3}' | tac)
  26         for m in ${mounts} ; do
  27                 echo "unmounting $m"
  28                 umount $m
  29         done
  30         if [[ -z ${mounts} ]] ; then
  31                 echo "nothing mounted in ${chroot}"
  32         fi
  33         exit 0
  34 }
  35
  36 while [[ -n $1 ]] ; do
  37         case $1 in
  38                 -u) do_umount ;;
  39                 -*) echo "unknown option $1"; exit 1 ;;
  40                 *)  break ;;
  41         esac
  42 done
  43
  44 maybe_mount() {
  45         local src=/$1 dst=${chroot}/${2:-$1}
  46         [[ -d ${src} ]] || return 0
  47         mkdir -p "${dst}"
  48         grep -sq "${dst}" /proc/mounts || mount ${mount_args} --bind "${src}" "${dst}"
  49 }
  50 for m in ${mounts} ; do
  51         maybe_mount ${m}
  52 done
  53
  54 get_type() {
  55         case $(file "$1") in
  56                 *x86-64*)         echo x86_64;;
  57                 *"Intel 80386"*)  echo i386;;
  58                 *32-bit*PowerPC*) echo ppc;;
  59                 *64-bit*PowerPC*) echo ppc64;;
  60         esac
  61 }
  62 bin_dst=$(get_type bin/bash)
  63 setarch=
  64 if [[ -n ${bin_dst} ]] && type -P setarch &>/dev/null ; then
  65         setarch="setarch ${bin_dst}"
  66 fi
  67
  68 if [[ ! -L etc/mtab ]] ; then
  69         rm -f etc/mtab
  70         ln -sf /proc/mounts etc/mtab
  71 fi
  72 etc="
  73         hosts
  74         locale.gen
  75         localtime
  76         resolv.conf
  77 "
  78 home="
  79         .inputrc
  80         .gdbinit
  81         .gitconfig
  82         .nanorc
  83 "
  84 for f in \
  85         $(printf 'etc/%s ' ${etc}) \
  86 ; do
  87         if [ -e "/${f}" ] ; then
  88                 cp /${f} ${f}
  89         fi
  90 done
  91 for f in ${home} ; do
  92         cp ~/${f} root/${f}
  93 done
  94
  95 unset LS_COLORS # format changes over time
  96 [[ $# -eq 0 ]] && set -- env HOME=/root /bin/bash -l
  97 exec \
  98         ${setarch} \
  99         chroot "${chroot}" \
 100         "$@"