function hetzner-rescue-configure {
local host="${1}"
    local packages=(
    'byobu' 'mosh'
    )
    # apt / conf
    echo -n "\
Acquire::AllowInsecureRepositories False;
Acquire::AllowWeakRepositories False;
Acquire::AllowDowngradeToInsecureRepositories False;
Acquire::Check-Valid-Until True;
APT::Install-Recommends False;
APT::Install-Suggests False;
APT::Get::Show-Versions True;
Dir::Etc::SourceParts '';
Dpkg::Progress True;
" > '/etc/apt/apt.conf'
    # apt / sources
    echo -n "\
deb https://deb.debian.org/debian buster main contrib non-free
deb https://deb.debian.org/debian buster-backports main contrib non-free
deb https://deb.debian.org/debian buster-updates main contrib non-free
deb https://deb.debian.org/debian-security buster/updates main contrib non-free
" > '/etc/apt/sources.list'
    # bash / rc
    main_link_bashrc
    # host name
    hostname "${host}"
    # 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
    # update catalog
    apt-get update
    #
    debian_disable_frontend
    # install packages
    apt-get install --assume-yes "${packages[@]}"
    #
    apt_clean_cache
}

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

function hetzner-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 "${MAIN_BASH_ROOT}/" "${user_host}:/etc/bash/"
    # call setup
    # TODO variable
    ssh "${user_host}" -- "source '/etc/bash/main.sh' ; hetzner-rescue-configure '${host}'"
    # create session
    ssh "${user_host}" -- byobu new-session -d
    # send keys
    ssh "${user_host}" -- byobu send-keys 'hetzner-rescue-install' 'C-m'
    # attach session
    mosh "${user_host}" -- byobu attach-session
else
    echo 'Host?'
    return 1
fi
}