#!/bin/bash -eu
# Download Raspbian Image, remove first-boot stuff, add repos and install packages.
#
# Open interactive Shell in chroot or write result to SD Card
#
# License: GNU General Public License, see http://www.gnu.org/copyleft/gpl.html for full text
#
# The following variables and arrays customize the behavior. To change them simply create a configuration
# file `rpi-image-creator.config` which overrides them.
#
# Add at least the following lines to override the internal ImmobilienScout24 configuration:
# INSTALL_PACKAGES=()
# ADD_REPOS=()
# ADD_REPO_KEYS=()

# Raspbian
RASPBIAN_URL=http://downloads.raspberrypi.org/raspbian/images/raspbian-2015-02-17/2015-02-16-raspbian-wheezy.zip
RASPBIAN_SHA1=b71d7b61f44e9bd582df71c9be494c271c97650f

# List of packages to install
INSTALL_PACKAGES=(
    is24-rpi-env
    is24-team-monitor
)

# List of packages to remove
PURGE_PACKAGES=(
    wolfram-engine # takes up too much space to run updates on downloaded image
)

# List of extra APT repositories
ADD_REPOS=(
    "deb http://debit/repo wheezy main"
)

# List of extra GPG keys to import from the LOCAL SYSTEM!
ADD_REPO_KEYS=(
    "0A9A9A5B"
)

# Extra command to run upon completion. This is run within a chroot environment.
# Example: CUSTOM_COMMAND="curl http://some.domain/script.sh | bash -i ; rm -f /some/file"
CUSTOM_COMMAND=""

############ End of User Cusomization

if [[ -r ./rpi-image-creator.config ]] ; then
    source ./rpi-image-creator.config
fi

function die {
    echo 1>&2 ERROR: "$*"
    exit 1
}

missing_deps=()
for prog in kpartx wget gpg parted qemu-arm-static ; do
    if ! type $prog &>/dev/null ; then
        missing_deps+=( $prog )
    fi
done
if (( ${#missing_deps[@]} > 0 )) ; then
    die "Missing required programs: ${missing_deps[*]}
    On Debian/Ubuntu try 'sudo apt-get install kpartx qemu-user-static'"
fi

# Constants
NL="$(echo)"

# taken from http://debian-handbook.info/browse/wheezy/sect.automatic-upgrades.html
MIRACLE_COMBINATION_AUTO_UPGRADE_SCRIPT="
#!/bin/bash -e
exec &>/var/log/miracle-combination-auto-upgrade.log
date
apt-get update
export DEBIAN_FRONTEND=noninteractive
yes '' | apt-get -y -o Dpkg::Options::='--force-confdef' -o Dpkg::Options::='--force-confold' dist-upgrade
"

function _op {
    "$@" &> >(sed -e 's/^/| /')
}

function _umount {
    for dir in "$@" ; do
        if grep -q "$dir" /proc/self/mounts ; then
            if ! umount -f "$dir" ; then
                die "Could not umount $dir, check running procs:$NL$(lsof 2>/dev/null | grep $(readlink -f $dir))"
            fi
        fi
    done
}

function _get_image {
    echo "Fetching $RASPBIAN_URL "
    mkdir -p download
    RASPBIAN_ARCHIVE_FILE=download/${RASPBIAN_URL##*/}
    wget --no-verbose --continue --directory-prefix download $RASPBIAN_URL || die "Download of $RASPBIAN_URL failed"
    echo -n "Checksum of "
    sha1sum --strict --check - <<<"$RASPBIAN_SHA1 *$RASPBIAN_ARCHIVE_FILE" || die "Download checksum validation failed, please check http://www.raspberrypi.org/downloads"
    unzip -q $RASPBIAN_ARCHIVE_FILE -d temp/ || die "Could not unzip $RASPBIAN_ARCHIVE_FILE"
}

function _open_image {
    echo "Loop-back mounting" temp/*.img
    kpartx="$(kpartx -av temp/*.img)" || die "Could not setup loop-back access to $RASPBIAN_ARCHIVE_FILE:$NL$kpartx"
    read img_boot_dev img_root_dev <<<$(grep -o 'loop.p.' <<<"$kpartx")
    test "$img_boot_dev" -a "$img_root_dev" || die "Could not extract boot and root loop device from kpartx output:$NL$kpartx"
    img_boot_dev=/dev/mapper/$img_boot_dev
    img_root_dev=/dev/mapper/$img_root_dev
    mkdir -p mnt/img_root
    mount -t ext4 $img_root_dev mnt/img_root || die "Could not mount $img_root_dev mnt/img_root"
    mkdir -p mnt/img_root/boot || die "Could not mkdir mnt/img_root/boot"
    mount -t vfat $img_boot_dev mnt/img_root/boot || die "Could not mount $img_boot_dev mnt/img_root/boot"
    cp -a "$(type -p qemu-arm-static)" mnt/img_root/usr/bin/ || die "Could not copy qemu-arm-static"
    echo "Raspbian Image Details:"
    df -h mnt/img_root/boot mnt/img_root | sed -e "s#$(pwd)/##"
}

function _modify_image {
    echo "Modifying Image"
    chroot mnt/img_root date &>/dev/null || die "Could not chroot date"
    mount -t devpts devpts -o noexec,nosuid,gid=5,mode=620 mnt/img_root/dev/pts || die "Could not mount /dev/pts"
    mount -t proc proc mnt/img_root/proc || die "Could not mount /proc"
    mount -t tmpfs -o mode=1777 none mnt/img_root/run || "Could not mount /run"
    sed -i -e 's/^/#/' mnt/img_root/etc/ld.so.preload || die "Could not disable ld.so.preload"
    rm -f mnt/img_root/etc/init.d/apply_noobs_os_config mnt/img_root/etc/rc2.d/S01apply_noobs_os_config mnt/img_root/etc/profile.d/raspi-config.sh \
        || die "Could not remove noobs and raspi-config first-boot stuff"
    sed -i -e '/RPICFG_TO_DISABLE/d' -e '/RPICFG_TO_ENABLE/s/^#//' -e '/RPICFG_TO_ENABLE/s/ #.*$//' mnt/img_root/etc/inittab || die "Could not remove raspi-config autorun from inittab"
    sed -i -e 's/^#\(FSCKFIX=\)no/\1yes/' mnt/img_root/etc/default/rcS || die "Could not enable automatic filesystem fix on boot" 
    for f in /etc/default/{keyboard,console-setup} /etc/{resolv.conf,localtime} ; do
        if [[ -r $f ]] ; then
            cp $f mnt/img_root/$f || die "Could not copy $f"
        fi
    done
    echo "localhost" > mnt/img_root/etc/hostname || die "Could not set hostname to localhost"
    echo "unset old_host_name # this will make the system always set the hostname from DHCP" \
        > mnt/img_root/etc/dhcp/dhclient-enter-hooks.d/unset_old_hostname || die "Could not apply fix http://blog.schlomo.schapiro.org/2013/11/setting-hostname-from-dhcp-in-debian.html"
    if [[ "${ADD_REPOS:-}" ]] ; then
        for repo in "${ADD_REPOS[@]}" ; do
            echo "$repo" 
        done > mnt/img_root/etc/apt/sources.list.d/rpi-image-creator.list || die "Could not add repos ${ADD_REPOS[@]}"
    fi
    if [[ ${ADD_REPO_KEYS:-} ]] ; then
        gpg --no-permission-warning --no-default-keyring --keyring /etc/apt/trusted.gpg --export ${ADD_REPO_KEYS[@]} | gpg --no-permission-warning --no-default-keyring --keyring mnt/img_root/etc/apt/trusted.gpg --trustdb-name mnt/img_root/etc/apt/trustdb.gpg --import - || die "Could not import GPG keys ${ADD_REPO_KEYS[@]} for apt"
    fi
    IFS=: read a b c d e user_home g < <(getent passwd ${SUDO_USER:-$USER})
    mkdir -p mnt/img_root/root/.ssh || die "Could not mkdir mnt/img_root/root/.ssh"
    cat $user_home/.ssh/*.pub <<<"" >mnt/img_root/root/.ssh/authorized_keys || :
    chmod 0600 mnt/img_root/root/.ssh/authorized_keys || die "Could not chmod 0600 mnt/img_root/root/.ssh/authorized_keys"
    if (( $(wc -l <mnt/img_root/root/.ssh/authorized_keys) > 0 )) ; then
        echo "Installed SSH keys from $user_home, disabling password access"
        sed -i -e 's/.*PasswordAuthentication.*/PasswordAuthentication no/i' mnt/img_root/etc/ssh/sshd_config || die "Could not disable password auth in mnt/img_root/etc/ssh/sshd_config"
    fi
    sed -i -e 's/.*disable_overscan=.*/disable_overscan=1/i' mnt/img_root/boot/config.txt || die "Could not disable overscan in mnt/img_root/boot/config.txt"

    PURGE_PACKAGES=( $(
        for package in "${PURGE_PACKAGES[@]}" ; do
            if chroot mnt/img_root dpkg -s "$package" &>/dev/null ; then
                echo "$package"
            fi
        done
    ) )
    if [[ ${PURGE_PACKAGES:-} ]] ; then
        echo "Removing unwanted packages ${PURGE_PACKAGES[@]}"
        _op chroot mnt/img_root apt-get -qq purge "${PURGE_PACKAGES[@]}" || die "Could not remove ${PURGE_PACKAGES[@]}"
    fi

    echo "Installing Updates"
    _op chroot mnt/img_root apt-get -qq update || die "Could not update package sources"
    _op chroot mnt/img_root apt-get -qq dist-upgrade || die "Could not upgrade system"
    if [[ ${INSTALL_PACKAGES:-} ]] ; then
        echo "Installing ${INSTALL_PACKAGES[@]}"
        _op chroot mnt/img_root apt-get -qq install ${INSTALL_PACKAGES[@]} || die "Could not install ${INSTALL_PACKAGES[@]}"
    fi
    
    if [[ "${CUSTOM_COMMAND:-}" ]] ; then
        echo "Running Custom Command: $CUSTOM_COMMAND"
        _op chroot mnt/img_root bash -x -c "$CUSTOM_COMMAND" || die "Custom command failed"
    fi
    chroot mnt/img_root service rsyslog stop &>/dev/null || : # some packages start syslog
}

function _create_sdcard {
    # putting it all onto SD card
    DEST_DEVICE="$1"
    test -b "$DEST_DEVICE" || die "Must give block device with SD Card as first parameter"

    _umount mnt/img_root/{proc,sys,run,dev/pts}
    
    echo "Preparing SD card in $DEST_DEVICE"
    umount -f ${DEST_DEVICE}* &>/dev/null || :
    dd if=/dev/zero of=$DEST_DEVICE bs=1M count=100 status=none || die "Could not wipe SD card in $DEST_DEVICE"
    parted -a minimal -s $DEST_DEVICE mklabel msdos mkpart primary fat32 0mb 64mb mkpart primary ext2 64mb 100% set 1 boot on || die "Could not parted $DEST_DEVICE"
    if [ -e ${DEST_DEVICE}p1 ] ; then sd_boot_dev=${DEST_DEVICE}p1 ; elif [ -e ${DEST_DEVICE}1 ] ; then sd_boot_dev=${DEST_DEVICE}1 ; else die "Could not find sd-card partition 1" ; fi
    if [ -e ${DEST_DEVICE}p2 ] ; then sd_root_dev=${DEST_DEVICE}p2 ; elif [ -e ${DEST_DEVICE}2 ] ; then sd_root_dev=${DEST_DEVICE}2 ; else die "Could not find sd-card partition 2" ; fi
    mkdir -p mnt/sd_boot mnt/sd_root
    mkfs.vfat >/dev/null -n RASPBIAN_BOOT -F 32 $sd_boot_dev -m - <<<"This is the boot partition of a Raspbian image intended for a Raspberry Pi" || die "Could not create boot partition"
    mkfs.ext4 -q -L raspbian_root -E discard $sd_root_dev || die "Could not create root partition"
    tune2fs >/dev/null $sd_root_dev -o journal_data,discard || die "Could not tune2fs $sd_root_dev"
    mount -o data=writeback,nobarrier -t ext4 $sd_root_dev mnt/sd_root || die "Could not mount $sd_boot_dev mnt/sd_boot"
    mkdir -p mnt/sd_root/boot || die "Could not mkdir boot"
    mount -t vfat $sd_boot_dev mnt/sd_root/boot || die "Could not mount $sd_boot_dev mnt/sd_root/boot"

    echo "Copying files to SD card."
    cp -a mnt/img_root/* mnt/sd_root/ || die "Could not copy root fs"

    echo "SD Card Details:"
    _op parted -s $DEST_DEVICE print
    df -h mnt/sd_root/boot mnt/sd_root | sed -e "s#$(pwd)/##"

    sed -i -e 's/#//' mnt/sd_root/etc/ld.so.preload || die "Could not enable ld.so.preload"
    echo
    echo "SD Card Creation finished, please wait for script to complete."
}

export LANG="C" LANGUAGE="C" LC_ALL="C.UTF-8"
shopt -s nullglob

DESTDEVICE=
if [[ -b "${1:-}" ]] ; then
    DESTDEVICE="$1"
fi

if [[ $# -eq 0 || "$*" == *-h* ]] ; then
    echo "
Usage: $0 <--chroot|/dev/mmcblk0>

Download Raspbian Image, remove first-boot stuff, add repos and install packages.

Open interactive Shell in chroot or write result to SD Card

License: GNU General Public License, see http://www.gnu.org/copyleft/gpl.html for full text
"
    exit 1
fi

if [[ "$USER" != root && $(id -u) != "0" ]] ; then
    # restart as root
    echo "Switching over to run as root"
    exec sudo "$(readlink -f "$0")" "$@"
    echo "Need sudo permission to run as root!"
    exit 1
fi

rm -Rf mnt temp
mkdir -p temp
function exittrap {
    set +u +e
    _umount mnt/img_root/{proc,sys,run,dev/pts} mnt/sd_root/bo?t mnt/img_root/boot mnt/sd_ro?t mnt/img_root
    kpartx -d temp/*.img >/dev/null
    echo "Script execution time: $SECONDS seconds"
}
trap exittrap 0
trap exittrap ERR


_get_image
_open_image
_modify_image

if [[ "$DESTDEVICE" ]] ; then
    _create_sdcard "$DESTDEVICE"
elif [[ "$1" == "--chroot" ]] ; then
    echo "Starting interactive Shell in image chroot"
    chroot mnt/img_root bash -i
    exit 0
else
    die "Usage error. Try $0 --help"
fi


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