backup raspberry pi sd image

backup_sd.sh

#!/bin/bash

set -exu

BOOTDEV=/dev/mmcblk0p1
ROOTDEV=/dev/mmcblk0p2

MOUNT_POINT=/mnt
[[ -d $MOUNT_POINT ]] || mkdir -p $MOUNT_POINT

TMPDIR=/tmp/
FILE="${1:-/tmp/rpi-`date +%Y%m%d%H%M%S`.img}"

USE_DUMP=false

color_echo()
{
    local color
    color="$1"
    shift
    echo -e '\033['"$color"'m'"$@"'\033[0m'
}
green()
{
    color_echo '1;32' "$@"
}
blue()
{
    color_echo '0;36' "$@"
}
yellow()
{
    color_echo '1;33' "$@"
}
red()
{
    color_echo '1;31' "$@"
}

exit_with_error()
{
    red "${1:-error!!!}"
    exit 1
}

check_root()
{
    if [ `whoami` != "root" ];then
        exit_with_error "This script must be run as root!"
    fi
}

install_software()
{
    apt update
    apt install -y dosfstools parted kpartx rsync
    green "software is ready"
}


create_img_file()
{
    local file disksize 
    file="${1}"
    disksize="${2}"
    dd if=/dev/zero of="$file" bs=1K count=0 seek="$disksize"
}

make_part_for_img_file()
{
    local file fat32_start fat32_end ext4_start
    file="${1}"
    fat32_start="${2}s"
    fat32_end="${3}s"
    ext4_start="${4}s"

    parted $file --script -- mklabel msdos
    parted $file --script -- mkpart primary fat32 $fat32_start $fat32_end
    parted $file --script -- mkpart primary ext4 $ext4_start -1
}

create_img_file_and_part()
{
    local file="${1}"

    local boot_total_size=$(df -P $BOOTDEV | tail -n 1 | awk '{print $2}')
    local root_used_size=$(df -P $ROOTDEV | tail -n 1 | awk '{print $3}')
    local scale
    $USE_DUMP && scale=1.2 || scale=1.5
    local disksize=$(echo $boot_total_size $root_used_size |awk '{print int(($1+$2)*'${scale}')}')

    blue "disksize is $disksize"

    create_img_file $file $disksize

    local tmp=$(fdisk -l |grep $BOOTDEV |grep -Eo '\b[0-9]+\b' | tr '\n' ' ')
    local fat32_start=$(echo $tmp | awk '{print $1}')
    local fat32_end=$(echo $tmp | awk '{print $2}')
    local ext4_start=$(fdisk -l |grep $ROOTDEV |grep -Eo '\b[0-9]+\b'| head -n 1)

    blue "fat32_start=$fat32_start fat32_end=$fat32_end ext4_start=$ext4_start"

    make_part_for_img_file $file $fat32_start $fat32_end $ext4_start

    green "create $file and parted it success"
}

backup_rootdev_rsync()
{
    local file="$1"

    local EXCLUDE_SWAPFILE=""
    if [ -f /etc/dphys-swapfile ]; then
        local SWAPFILE=`cat /etc/dphys-swapfile | grep ^CONF_SWAPFILE | cut -f 2 -d=`
        if [ "$SWAPFILE" = "" ]; then
            SWAPFILE=/var/swap
        fi
        EXCLUDE_SWAPFILE="--exclude $SWAPFILE"
    fi

    local boot_mnt=$(findmnt -n $BOOTDEV | awk '{print $1}')
    [[ -n $boot_mnt ]] || exit_with_error "boot_mnt empty"

    rsync --force -rltWDEgop --delete --stats --progress \
        $EXCLUDE_SWAPFILE \
        --exclude ".gvfs" \
        --exclude "$boot_mnt" \
        --exclude "/dev" \
        --exclude "/media" \
        --exclude "$MOUNT_POINT" \
        --exclude "/proc" \
        --exclude "/run" \
        --exclude "/snap" \
        --exclude "/sys" \
        --exclude "/tmp" \
        --exclude "lost\+found" \
        --exclude "$file" \
        / $MOUNT_POINT

    if [ -d /snap ]; then
        mkdir $MOUNT_POINT/snap
    fi

    for i in boot dev media mnt proc run sys boot; do
        if [ ! -d $MOUNT_POINT/$i ]; then
            mkdir $MOUNT_POINT/$i
        fi
    done

    if [ ! -d $MOUNT_POINT/tmp ]; then
        mkdir $MOUNT_POINT/tmp
        chmod a+w $MOUNT_POINT/tmp
    fi

}

backup_rootdev_dump()
{
    sudo dump -0uaf $TMPDIR/tmp12345 /

    pushd $MOUNT_POINT
    sudo restore -rf $TMPDIR/tmp12345
    popd
    #sudo dump -0uaf $MOUNT_POINT/rootdev.dump / # sudo restore -rf rootdev.dump
    #sudo cp rootdev.dump $MOUNT_POINT
}

mkfs_and_mount_and_cp_files()
{
    local file="$1"

    local boot_label=$(dosfslabel $BOOTDEV | tail -n 1)
    local root_label=$(e2label $ROOTDEV | tail -n 1)

    local loopdevice=`losetup -f --show $file | tail -n 1`
    kpartx -va $loopdevice
    local device="/dev/mapper/$(basename $loopdevice)"

    local partBoot="${device}p1"
    local partRoot="${device}p2"

    [[ -e "$partBoot" ]] || exit_with_error "$partBoot not exist"
    [[ -e "$partRoot" ]] || exit_with_error "$partRoot not exist"


    mkfs.vfat -F 32 -n "$boot_label" $partBoot

    mkfs.ext4 $partRoot
    e2label $partRoot $root_label

    mount -t vfat $partBoot $MOUNT_POINT

    # boot mount point
    local boot_mnt=$(findmnt -n $BOOTDEV | awk '{print $1}')
    [[ -n $boot_mnt ]] || exit_with_error "boot_mnt empty"

    cp -rfp ${boot_mnt}/* $MOUNT_POINT/

    local opartuuidb=`blkid -o export $BOOTDEV | grep PARTUUID`
    local opartuuidr=`blkid -o export $ROOTDEV | grep PARTUUID`

    local npartuuidb=`blkid -o export ${partBoot} | grep PARTUUID`
    local npartuuidr=`blkid -o export ${partRoot} | grep PARTUUID`

    sed -i "s/$opartuuidr/$npartuuidr/g" $MOUNT_POINT/cmdline.txt

    sync

    umount $MOUNT_POINT

    mount -t ext4 $partRoot $MOUNT_POINT

    if $USE_DUMP; then
        backup_rootdev_dump
    else
        backup_rootdev_rsync $file
    fi

    sed -i "s/$opartuuidb/$npartuuidb/g" $MOUNT_POINT/etc/fstab
    sed -i "s/$opartuuidr/$npartuuidr/g" $MOUNT_POINT/etc/fstab

    sync

    umount $MOUNT_POINT

    kpartx -d $loopdevice
    losetup -d $loopdevice
    green "mkfs and cp files success"
}

check_root
#install_software
create_img_file_and_part $FILE
mkfs_and_mount_and_cp_files $FILE
green "All done."