changeimg_raw

#!/bin/bash
set -euo pipefail

# A tool to manipulate a VDI image. Useful for adding/removing users,
# changing passwords, setting up ssh keys, etc. without starting the VM.

OP=${1-}

fatal() {
    printf %s\\n "fatal error: $@"
    exit 1
}

_get_loopdev() {
    DISK=$1
    losetup -a | awk -F: "/$(basename ${DISK})/ { print \$1 }"
}

setup() {
    DISK="${2-}"
    [ ! -f "$DISK" ] && fatal "usage: $0 setup <harddisk.raw>"
    LOOPDEV=`_get_loopdev ${DISK}`
    if [ -z "$LOOPDEV" ]; then
        LOOPDEV=`losetup -fv $DISK | awk '{ print $NF; exit }'`
    fi
    if [ -z "$LOOPDEV" ]; then
        fatal "failed to attach $DISK to /dev/loopX"
    fi
    LOOPP1=/dev/mapper/${LOOPDEV#/dev/}p1
    [ ! -b $LOOPP1 ] && kpartx -sa $LOOPDEV
    [ ! -b $LOOPP1 ] && fatal "kpartx -sa $LOOPDEV failed"
    mkdir -p target
    if [ ! -f target/vmlinuz ]; then
        mount $LOOPP1 target || fatal "mount $LOOPP1 failed"
    fi
    echo Setup successful
}

cleanup() {
    DISK="${2-}"
    [ ! -f "$DISK" ] && fatal "usage: $0 setup <harddisk.raw>"
    if [ -f target/vmlinuz ]; then
        umount target || fatal "umount target failed"
    fi
    LOOPDEV=`_get_loopdev ${DISK}`
    LOOPP1=/dev/mapper/${LOOPDEV#/dev/}p1
    [ -b $LOOPP1 ] && kpartx -d $LOOPDEV
    [ -b $LOOPP1 ] && fatal "kpartx -d $LOOPDEV failed"
    [ -n "`_get_loopdev ${DISK}`" ] && losetup -d $LOOPDEV
    [ -n "`_get_loopdev ${DISK}`" ] && fatal "losetup -d $LOOPDEV failed"
    echo Cleanup successful
}

local_run() {
    SCRIPT="$2"
    [ ! -x "$SCRIPT" ] && fatal "usage: changeimg local_run <executable> <args>"
    [ ! -f target/vmlinuz ] && fatal "run setup first"

    cp "$SCRIPT" target/tmp/liox_tmp
    shift;
    exec chroot target tmp/liox_tmp "$@"
}

chroot() {
    [ ! -f target/vmlinuz ] && fatal "run setup first"
    [ -z "$2" ] && exec chroot target /bin/bash -i
    shift;
    exec chroot target "$@"
}

case $OP in
    setup )
        setup "$@"
        ;;
    local_run )
        local_run "$@"
        ;;
    chroot )
        chroot "$@"
        ;;
    cleanup )
        cleanup "$@"
        ;;
    * )
        echo "Usage: $0 (setup|local_run|chroot|cleanup)" ;;
esac