function ovh-rescue-setup {
    # apt / conf
    echo -n "\
Acquire::AllowInsecureRepositories False;
Acquire::AllowWeakRepositories False;
Acquire::AllowDowngradeToInsecureRepositories False;
Acquire::Check-Valid-Until True;
APT::Install-Recommends False;
APT::Install-Suggests False;
APT::Get::Show-Versions True;
Dir::Etc::SourceParts '';
Dpkg::Progress True;
" > '/etc/apt/apt.conf'
    # apt / sources
    echo -n "\
deb https://deb.debian.org/debian buster main contrib non-free
deb https://deb.debian.org/debian buster-backports main contrib non-free
deb https://deb.debian.org/debian buster-updates main contrib non-free
deb https://deb.debian.org/debian-security buster/updates main contrib non-free
" > '/etc/apt/sources.list'
    # bash / rc
    link_bashrc
    # host name
    echo -n 'ovh' > '/etc/hostname'
    # locales
    echo -n "\
en_US.UTF-8 UTF-8
fr_FR.UTF-8 UTF-8
" > '/etc/locale.gen'
    # fix alias
    rm --force '/usr/share/locale/locale.alias'
    ln --symbolic '/etc/locale.alias' '/usr/share/locale/locale.alias'
    # generate locales
    locale-gen
}

function ovh-rescue-install {
    local release='buster'
    local packages=(
    'byobu' 'mosh'
    'parted' 'mdadm' 'lvm2'
    'lshw'
    'file'
    'grub-efi-amd64-bin' 'grub-pc-bin'
    'htop' 'iotop' 'lsof'
    'exa' 'ncdu' 'nnn' 'ranger' 'tree'
    'squashfs-tools'
    'uuid-runtime'
    )
    local backports=(
    'cryptsetup-bin'
    'git'
    'rsync'
    )
    # update catalog
    apt-get update
    #
    export DEBIAN_FRONTEND='noninteractive'
    # upgrade packages
    apt-get upgrade --assume-yes
    # install packages
    apt-get install --assume-yes "${packages[@]}"
    # install backports
    apt-get install --assume-yes \
    --target-release "${release}-backports" "${backports[@]}"
    # clean cache
    apt-get clean
}

function ovh-rescue-upload {
local host="${1}"
if [ "${host}" ] ; then
    local user='root'
    #
    local user_host="${user}@${host}"
    # remove fingerprints
    ssh-keygen -R "${host}"
    # copy ssh id
    ssh-copy-id \
    -o 'StrictHostKeyChecking=accept-new' \
    "${user_host}"
    # upload root
    rsync --delete --recursive "${MAIN_ROOT}/" "${user_host}:/etc/bash/"
    # call setup
    ssh "${user_host}" -- "source '/etc/bash/main.sh' ; ovh-rescue-setup"
    # create session
    ssh "${user_host}" -- byobu new-session -d
    # attach session
    mosh "${user_host}" -- byobu attach-session
else
    echo 'Host?'
    return 1
fi
}

function ovh-rescue-wipe-1-2TB {
    local device='/dev/sda'
    local unit='mib'
    #
    echo -n 'WIPE' "${device}" '/?\ OR CANCEL /!\'
    read
    #
    parted "${device}" --script mktable gpt
    #
    parted "${device}" unit "${unit}" mkpart 'crypt' 65795 1907729
    #
    parted "${device}" unit "${unit}" mkpart 'boot' 259 65795
    #
    parted "${device}" unit "${unit}" mkpart 'esp' 2 259
    parted "${device}" set 3 esp on
    #
    parted "${device}" unit "${unit}" mkpart bios 1 2
    parted "${device}" set 4 bios_grub on
    # wipe bios
    dd if='/dev/zero' of='/dev/sda4'
    # format esp
    mkfs.vfat -F 32 -n 'esp' '/dev/sda3'
    # format boot
    mkfs.ext4 -L 'boot' '/dev/sda2'
    # read passphrase
    local passphrase
    read -r -s passphrase
    # encrypt
    echo "${passphrase}" \
    | cryptsetup \
    --verbose \
    --batch-mode \
    --type 'luks2' \
    --pbkdf 'argon2id' \
    --cipher 'aes-xts-plain64' \
    --iter-time 8192 \
    --key-size 512 \
    --hash 'sha512' \
    --use-random \
    luksFormat \
    '/dev/sda1'
    # open
    echo "${passphrase}" \
    | cryptsetup luksOpen '/dev/sda1' 'crypt'
    # pv
    pvcreate '/dev/mapper/crypt'
    # vg
    vgcreate 'crypt' '/dev/mapper/crypt'
    # lv swap
    lvcreate --name 'swap' --size '68719476736b' 'crypt'
    # lv data
    lvcreate --name 'data' --extents '100%FREE' 'crypt'
    # format swap
    mkswap --label 'swap' '/dev/mapper/crypt-swap'
    # format data
    mkfs.ext4 -L 'data' '/dev/mapper/crypt-data'
    # vg off
    vgchange --activate n 'crypt'
    # close
    cryptsetup luksClose 'crypt'
}