#!/bin/bash

#
# LXC template for gentoo
#
# Author: Guillaume Zitta <lxc@zitta.fr>
#
# Widely inspired from lxc-gentoo script at https://github.com/globalcitizen/lxc-gentoo
#
# this version is reworked with :
# - out of the lxc-create compat
# - vanilla gentoo config
# - ready to use cache
#

# Detect use under userns (unsupported)
for arg in "$@"; do
    [ "$arg" = "--" ] && break
    if [ "$arg" = "--mapped-uid" -o "$arg" = "--mapped-gid" ]; then
        echo "This template can't be used for unprivileged containers." 1>&2
        echo "You may want to try the \"download\" template instead." 1>&2
        exit 1
    fi
done

# Make sure the usual locations are in PATH
export PATH=$PATH:/usr/sbin:/usr/bin:/sbin:/bin

# Ensure strict root's umask doesen't render the VM unusable
umask 022

LXC_TEMPLATE_CONFIG="@LXCTEMPLATECONFIG@"

################################################################################
#                        Various helper functions
################################################################################

# param: $1: the name of the lock
# param: $2: the timeout for the lock
# The rest contain the command to execute and its parameters
execute_exclusively()
{
    mkdir -p @LOCALSTATEDIR@/lock/subsys/

    local lock_name="$1"
    local timeout="$2"
    shift 2

    {
        printf "Attempting to obtain an exclusive lock (timeout: %s sec) named \"%s\"...\n" "${timeout}" "$lock_name"

        flock -x -w "${timeout}" 50

        if [[ $? -ne 0 ]]; then
            printf " => unable to obtain lock, aborting.\n"
            return 2
        else
            printf " => done.\n"
        fi

        printf " => Executing \"%s\"\n" "$*"
        "$@"
        retval=$?
    } 50> "@LOCALSTATEDIR@/lock/subsys/lxc-gentoo-${lock_name}"
    return $retval
}

# a die function is always a good idea
die()
{
    printf "\n[the last exit code leading to this death was: %s ]\n" "$?"
    local retval="$1"
    shift 1
    printf "$@"
    exit "$retval"
}

# gentoo arch/variant detection
set_default_arch()
{
    printf "### set_default_arch: default arch/variant autodetect...\n"
    arch=$(uname -m)
    if [[ $arch =~ i.86 ]]; then
        arch="x86"
        variant="x86"
    elif [[ $arch == "x86_64" ]]; then
        arch="amd64"
        variant="amd64"
    elif [[ $arch =~ arm.* ]]; then
        arch="arm"
        variant="armv7a"
    elif [[ $arch == "aarch64" ]]; then
        arch="arm64"
        variant="arm64-openrc"
    else
        #who knows, it may work...
        printf " => warn: unexpected arch:${arch} let me knows if it works :)\n"
        variant="${arch}"
    fi
    printf " => Got: arch=%s variant=%s\n" "${arch}" "${variant}"
}

store_user_message()
{
    user_message="${user_message}=> $@\n"
}

################################################################################
#                    CACHE Preparation
################################################################################
# during setup cachedir is $cacheroot/partial-$arch-$variant
# at the end, it will be   $cacheroot/rootfs-$arch-$variant

cache_setup(){
    partialfs="${cacheroot}/partial-${arch}-${variant}"

    #if cache exists and flush not needed, return
    [[ -d "${cachefs}" && -z "${flush_cache}" ]] && return 0

    printf "###### cache_setup(): doing cache preparation\n"
    local retval=1

    #clean from failed previous run
    rm -rf "${partialfs}"
    mkdir -p "${partialfs}"

    #let's go
    cache_precheck && \
    cache_stage3 && \
    cache_portage && \
    cache_inittab && \
    cache_net && \
    cache_dev && \
    cache_openrc && \
    cache_locale && \
    rm -rf "${cachefs}" && \
    mv "${partialfs}" "${cachefs}" && \
    printf "###### cache_setup: Cache should be ready\n"

    return $?
}

cache_precheck()
{
    printf "### cache_precheck(): doing some pre-start checks ...\n"
    # never hurts to have a fail-safe.
    [[ -n "${cacheroot//\/}" ]] \
        || die 8 "\$cacheroot (%s) IS EMPTY OR MADE OF ONLY DIRECTORY SEPARATORS, THIS IS *VERY* BAD!\n" "${cacheroot}"
}

#get latest stage3 tarball
cache_stage3()
{
    printf "### cache_stage3(): stage3 cache deployment...\n"

    if [ -z "${tarball}" ]; then
        #variables init
        local stage3_baseurl="${mirror}/releases/${arch}/autobuilds"

        # get latest-stage3....txt file for subpath
        local stage3_pointer="${stage3_baseurl}/latest-stage3-${variant}.txt"

        printf "Determining path to latest Gentoo %s (%s) stage3 archive...\n" "${arch}" "${variant}"
        printf " => downloading and processing %s\n" "${stage3_pointer}"

        local stage3_latest_tarball=$(wget -q -O - "${stage3_pointer}" | tail -n1 | cut -d' ' -f1) \
            || die 6 "Error: unable to fetch\n"

        printf " => Got: %s\n" "${stage3_latest_tarball}"

        printf "Downloading/untarring the actual stage3 tarball...\n"

        compressor="j"
        if echo ${stage3_latest_tarball} | grep ".xz$"; then
            compressor="J"
        fi

        wget -O - "${stage3_baseurl}/${stage3_latest_tarball}" \
            | tar -x${compressor}pf - --numeric-owner -C "${partialfs}" \
            || die 6 "Error: unable to fetch or untar\n"
        printf " => extracted to: %s\n" "${partialfs}"
    else
        printf "Extracting the stage3 tarball...\n"
        tar -xpf "${tarball}" --numeric-owner -C "${partialfs}" \
            || die 6 "unable to untar ${tarball} to ${partialfs}"
    fi

    #check if it chroots
    printf "chroot test..."
    chroot ${partialfs} /bin/true || die 1 "Error: chroot %s /bin/true, failed" "${partialfs}"
    printf " OK\n"
    printf " => stage3 cache extracted in : %s\n" "${partialfs}"
    return 0
}

cache_portage()
{
    printf "### cache_portage: caching portage tree tarball...\n"
    [[ -z "${flush_cache}" && -f "${portage_cache}" ]] && return 0

    rm -f ${portage_cache}

    printf "Downloading Gentoo portage (software build database) snapshot...\n"
    execute_exclusively portage 60 wget -O "${portage_cache}" "${mirror}/snapshots/portage-latest.tar.bz2" \
    || die 6 "Error: unable to fetch\n"
    printf " => done.\n"
}

# custom inittab
cache_inittab()
{
    printf "### cache_inittab: tuning inittab...\n"

    INITTAB="${partialfs}/etc/inittab"

    [[ -w "$INITTAB" ]] || die 1 "Error: $INITTAB is not writeable"

    # create console
    echo "# Lxc main console" >> "$INITTAB"
    echo "1:12345:respawn:/sbin/agetty -a root --noclear 115200 console linux" >> "$INITTAB"

    # finally we add a pf line to enable clean shutdown on SIGPWR (issue 60)
    echo "# clean container shutdown on SIGPWR" >> "$INITTAB"
    echo "pf:12345:powerwait:/sbin/halt" >> "$INITTAB"

    # we also blank out /etc/issue here in order to prevent delays spawning login
    # caused by attempts to determine domainname on disconnected containers
    sed -i 's/[\][Oo]//g' "${partialfs}/etc/issue"
}

cache_net()
{
    printf "### cache_net: doing some useful net tuning...\n"
    # useful for chroot
    # /etc/resolv.conf
    grep -i 'search ' /etc/resolv.conf > "${partialfs}/etc/resolv.conf"
    grep -i 'nameserver ' /etc/resolv.conf >> "${partialfs}/etc/resolv.conf"

    # fix boot-time interface config wipe under aggressive cap drop
    # (openrc 0.9.8.4 ~sep 2012 - https://bugs.gentoo.org/show_bug.cgi?id=436266)
    # initial warkaround was: sed -i -e 's/^#rc_nostop=""/rc_nostop="net.eth0 net.lo"/' "${partialfs}/etc/rc.conf"
    # but this one does not depends on interfaces names
    echo 'rc_keyword="-stop"' >> "${partialfs}/etc/conf.d/net"
}

cache_dev()
{
    printf "### cache_dev(): /dev tuning...\n"

    #Wait for https://bugs.gentoo.org/show_bug.cgi?id=496054
    mkdir "${partialfs}/dev/pts"
    mkdir "${partialfs}/dev/shm"
    mkdir "${partialfs}/dev/mqueue"

    mkdir -m 755 "${partialfs}/dev/net"
    mknod -m 666 "${partialfs}/dev/net/tun"        c 10 200

    return 0
}

# fix openrc system
cache_openrc()
{
    printf "### cache_openrc(): doing openrc tuning\n"

    #Wait for https://bugs.gentoo.org/show_bug.cgi?id=496054
    chroot "${partialfs}" sed s/-lxc//g -i "/etc/init.d/devfs"

    return 0
}

cache_locale()
{
   printf "### cache_locale(): initiating minimale locale en_US.UTF-8 \n"

   echo "en_US.UTF-8 UTF-8" >> "${partialfs}/etc/locale.gen"
   chroot "${partialfs}" locale-gen

   return 0
}

################################################################################
#                    CONTAINER Preparation
################################################################################

container_setup() {
    printf "##### container_setup(): starting container setup\n"

    #in most cases lxc-create should have provided a copy of default lxc.conf
    #let's tag where template starts, or just create the files
    echo '### lxc-gentoo template stuff starts here' >> "$path/config"

    #Determine rootfs
    #If backingstore was specified, lxc.rootfs.path should be present or --rootfs did the rootfs var creation
    if [ -z "${rootfs}" ]; then
        rootfs=`awk -F= '$1 ~ /^lxc.rootfs.path/ { print $2 }' "$path/config" 2>/dev/null`
        if [ -z "${rootfs}" ]; then
            #OK it's default
            rootfs="${path}/rootfs"
        fi
    fi
    store_user_message "rootfs of container is : ${rootfs}"
    store_user_message "config of container is : ${path}/config"

    container_precheck && \
    container_rootfs && \
    container_consoles && \
    container_tz && \
    container_portage && \
    container_net && \
    container_hostname && \
    container_auth && \
    container_sshd && \
    container_conf
    if [ $? -ne 0 ]; then
        die 1 "container_setup(): one step didn't complete, sorry\n"
    fi

    printf "###### container_setup(): container should be ready to start!\n"
    printf "\n\n"
    printf "You could now use you container with: lxc-start -n %s\n" "${name}"
    printf "little things you should know about your container:\n"
    printf "${user_message}"
    return 0
}

container_precheck()
{
    printf "### container_precheck(): doing some pre-start checks ...\n"
    # never hurts to have a fail-safe.
    [[ -n "${name//\/}" ]] \
        || die 8 "\$name (%s) IS EMPTY OR MADE OF ONLY DIRECTORY SEPARATORS, THIS IS *VERY* BAD!\n" "${name}"

    [[ -n "${rootfs//\/}" ]] \
        || die 8 "\$rootfs (%s) IS EMPTY OR MADE OF ONLY DIRECTORY SEPARATORS, THIS IS *VERY* BAD!\n" "${rootfs}"

    [[ -n "${cachefs//\/}" ]] \
        || die 8 "\$cachefs (%s) IS EMPTY OR MADE OF ONLY DIRECTORY SEPARATORS, THIS IS *VERY* BAD!\n" "${cachefs}"

    # check if the rootfs already exists
    [[ -d "${rootfs}/etc" ]] && die 18 "Error: \$rootfs (%s) already exists!" "${rootfs}"

    # check cache
    [[ ! -d "${cachefs}/etc" ]] && die 1 "Error: \$cachefs (%s) not found!" "${cachefs}"

    return 0
}

container_rootfs()
{
    printf "#### container_rootfs(): copying rootfs %s from cache %s ...\n" "${rootfs}" "${cachefs}"
    tar -c -f - --numeric-owner -C "${cachefs}" . \
        | tar -x -p -f - --numeric-owner -C "${rootfs}" \
        || die 1 "Error: cache copy to rootfs failed"

    printf "chroot test..."
    chroot "${rootfs}" /bin/true || die 1 "Error: 'chroot %s /bin/true' failed"
    printf " OK\n"

    printf " => done\n"
    return 0
}

container_consoles() {
    printf "#### container_consoles(): setting container consoles ...\n"

    # disable unwanted ttys
    if [[ ${tty} < 6 ]]; then
        local mindis=$(( ${tty} + 1 ))
        sed -i "s/^c[${mindis}-6]/#&/" "${rootfs}/etc/inittab"
    fi
    printf " => main console + ${tty} ttys\n"

    if [[ -z "${autologin}" ]]; then
        sed 's/agetty -a root/agetty/' -i "${rootfs}/etc/inittab"
    elif [[ "${user}" != "root" ]]; then
        sed "s/agetty -a root/agetty -a ${user}/" -i "${rootfs}/etc/inittab"
        printf " => Autologin on main console for %s enabled\n" "${user}"
        [[ -z "${forced_password}" ]] && unset password
        store_user_message "${user} has autologin on main console"
    else
        printf " => Autologin on main console for root enabled\n"
        [[ -z "${forced_password}" ]] && unset password
        store_user_message "${user} has autologin on main console"
    fi
    printf " => done\n"
}

container_tz()
{
    printf "#### container_tz(): setting container timezone ...\n"

    #let's try to copy it from host
    if [ -L "/etc/localtime" ]; then
        #host has a symlink
        #let see if we can reproduct symlink
        target=$(readlink /etc/localtime)
        if [[ "$target" != "" ]]; then
            if [ -f "${rootfs}/${target}" ]; then
                #same target exists in container
                chroot "${rootfs}" ln -sf "${target}" "/etc/localtime"
                printf " => host symlink reproducted in container : %s\n" "${target}"
                store_user_message "timezone copyed from host"
                return 0
            fi
        fi
    fi

    if [ -e /etc/localtime ]; then
        # duplicate host timezone
        cat /etc/localtime > "${rootfs}/etc/localtime"
        printf " => host localtime copyed to container\n"
        store_user_message "timezone was staticly copyed from host"
    else
        # otherwise set up UTC
        chroot "${rootfs}" ln -sf /usr/share/zoneinfo/UTC /etc/localtime
        printf " => fallback: fixed to UTC\n"
        store_user_message "timezone was fixed to UTC"
    fi
}


container_portage()
{
    printf "#### container_portage(): setting container portage... \n"

    #default entry for conf
    portage_mount="#container set with private portage tree, no mount here"

    printf "Warnings are normal here, don't worry\n"
    #container repos detection
    if chroot ${rootfs} portageq get_repo_path / gentoo > /dev/null ; then
        portage_container="$(chroot ${rootfs} portageq get_repo_path / gentoo)"
    else
        die 1 "Failed to figure out container portage tree location with portageq get_repo_path / gentoo\n"
    fi

    if [[ -n "${private_portage}" ]]; then
        container_private_portage
        return 0
    fi

    if [ -z "${portage_dir}" ]; then
        #gentoo host detection
        printf "trying to guess portage_dir from host...\n"
        portage_dir="$(portageq get_repo_path / gentoo 2>/dev/null)"
        if [ ! -d "${portage_dir}/profiles" ]; then
            printf " => host portage detection failed (not gentoo host), fallback to private portage tree\n"
            container_private_portage
            return 0
        fi
    else
        if [ ! -d "${portage_dir}/profiles" ]; then
            die 1 "specified portage_dir (%s) does not contains profiles, is it a portage tree ?\n" "${portage_dir}"
        fi
    fi

    printf "trying to guess portage distfiles dir from host ...\n"
    portage_distfiles_dir="$(portageq distdir 2>/dev/null)"
    if [ ! -d "${portage_distfiles_dir}" ]; then
        portage_distfiles_dir="${portage_dir}/distfiles"
    fi

    # if we are here, we have shared portage_dir
    #ensure dir exists
    chroot "${rootfs}" mkdir ${portage_container}
        portage_mount="#container set with shared portage
lxc.mount.entry=${portage_dir} ${portage_container/\//} none ro,bind 0 0
lxc.mount.entry=${portage_distfiles_dir} ${portage_container/\//}/distfiles none rw,bind 0 0
#If you use eix, you should uncomment this
#lxc.mount.entry=/var/cache/eix var/cache/eix none ro,bind 0 0"
    store_user_message "container has a shared portage from host's ${portage_dir} to ${portage_container/\//}"
        #Let's propose binary packages
    cat <<- EOF >> "${rootfs}/etc/portage/make.conf"
# enable this to store built binary packages
#FEATURES="\$FEATURES buildpkg"

# enable this to use built binary packages
#EMERGE_DEFAULT_OPTS="\${EMERGE_DEFAULT_OPTS} --usepkg"

# enable and *tune* this kind of entry to slot binaries, specialy if you use multiples archs and variants
#PKGDIR="\${PKGDIR}/amd64
#or PKGDIR="\${PKGDIR}/hardened"
EOF
    printf " => portage stuff done, see /etc/portage/make.conf for additional tricks\n"

}

container_private_portage()
{
    #called from container_portage() do not call directly from container_setup
    printf "# untaring private portage to %s from %s ... \n" "${rootfs}/${portage_container}" "${portage_cache}"
    mkdir -p "${rootfs}/${portage_container}"
    execute_exclusively portage 60 \
        tar -xp --strip-components 1 -C "${rootfs}/${portage_container}" \
        -f "${portage_cache}" --numeric-owner \
        || die 2 "Error: unable to extract the portage tree.\n"
    store_user_message "container has its own portage tree at ${portage_container}"
    printf "=> done\n"
}

#helper func for container_genconf_net()
nic_write()
{
    #display with gentoo's confd.net format
    echo "config_${nic_name}=\"${nic_conf}\""
    #add to managed list
    [[ "${nic_conf}" == "dhcp" ]] && nic_managed="${nic_managed} ${nic_name}"
    [[ "${nic_conf}" == "null" ]] && nic_unmanaged="${nic_unmanaged} ${nic_name}"
    [[ -z "${nic_hwaddr}" && ${nic_type} == "veth" ]] && nic_wo_hwaddr="${nic_wo_hwaddr} ${nic_name}"
    nic_writed=1
}

#Analyse lxc.conf and print conf.d/net content
container_conf_net()
{
    local file=${1}
    [[ -z "${nic_last}" ]] && nic_last=-1
    [[ -z "${nic_named}" ]] && nic_named=0
    OLDIFS=$IFS
    IFS="
"
    #let's do some drity bash things to parse lxc network conf
    for line in $( sed -r "s/[ ]*=[ ]*/_real_ugly_sep_42_/" "${file}" ); do
        key=$(echo "${line}" | sed 's/_real_ugly_sep_42_.*$//')
        value=$(echo "${line}" | sed 's/^.*_real_ugly_sep_42_//')

        #new nic !
        if [[ "${key}" == "lxc.net.0.type" ]]; then
            #we don't know what to do with it.
            [[ "${value}" == "empty" ]] && continue

            #write conf from previous loops
            [[ "${nic_writed}" == "0" ]] && nic_write

            #init defaults
            let nic_last=nic_last+1

            nic_writed=0
            #if 1 named between 2 not named: last is eth1
            #=> Number is ID munis number of named NIC before
            nic_name="eth$(( ${nic_last} - ${nic_named} ))"
            nic_conf="dhcp"
            nic_type="${value}"
        fi

                if [[ "${key}" == "lxc.net.0.hwaddr" ]]; then
                nic_hwaddr=1
        fi

        if [[ "${key}" =~ ^lxc.net.0.ipv(4|6) ]]; then
            #tell openrc to not manage this NIC as LXC set there address
            nic_conf="null"
        fi
        if [[ "${key}" =~ ^lxc.net.0.name ]]; then
            nic_name="${value}"
            let nic_named=nic_named+1
        fi
        if [[ "${key}" == "lxc.include" ]]; then
            #recursive into include
            container_conf_net "${value}"
        fi
    done
    #write conf from previous loops
    [[ "${nic_writed}" == "0" ]] && nic_write
    IFS=$OLDIFS
}

container_net()
{
    printf "container_net(): setting container network conf... \n"

    #Analyse network configuration in config
    container_conf_net "$path/config" >> "${rootfs}/etc/conf.d/net"

        # found how much nic finally have
    nic_count=$(( ${nic_last} + 1 ))

        # unless openrc manage a nic, we now have to force openrc to automatic
    # provision of the 'net' dep. If we do not, network dependent services
    # will fail to load
    if [[ -z "${nic_managed}" ]]; then
        #tell openrc that lxc already did the work
        echo 'rc_provide="net"' >> "${rootfs}/etc/rc.conf"
    fi

    #No NIC ?
    if [[ ${nic_count} == 0 ]]; then
        #If no Nic, no need to continue
        bridge=$(brctl show | awk 'NR==2 {print $1}')
        if [[ "${bridge}" != "" ]]; then
                        store_user_message "No network interface for this container
It's a pitty, you have bridge, ${bridge}.
If it is for Lxc, use it next time by adding this to your default.conf :
lxc.net.0.type = veth
lxc.net.0.link = ${bridge}
lxc.net.0.flags = up
lxc.net.0.hwaddr = fe:xx:xx:xx:xx:xx"
                        return 0
        else
                store_user_message "No network interface for this container"
                        return 0
        fi
    fi

    #For each openrc managed nic, activate
    sys_nic_index=1
    for nic in ${nic_managed}
    do
        chroot "${rootfs}" ln -s net.lo "/etc/init.d/net.${nic}"
        chroot "${rootfs}" rc-update add net.${nic} default
        #fake sysfs for openrc, in case settings does not provide it
        mkdir -p "${rootfs}/sys/class/net/${nic}"
        echo ${sys_nic_index} > "${rootfs}/sys/class/net/${nic}/ifindex"
        echo up > "${rootfs}/sys/class/net/${nic}/operstate"
        let sys_nic_index=sys_nic_index+1
    done

        #Warn about dynamic hwaddr
    if [[ -n "${nic_wo_hwaddr}" ]]; then
                store_user_message "Warning, these veth NIC don't have fixed hwaddr :
${nic_wo_hwaddr}

see http://lists.linuxcontainers.org/pipermail/lxc-devel/2013-December/006736.html
and man lxc.conf"
    fi

    printf " => network conf done.\n"
}

# custom hostname
container_hostname()
{
    printf "#### container_hostname(): setting hostname... \n"
    printf "hostname=\"%s\"\n" "${name}" > "${rootfs}/etc/conf.d/hostname"
    printf " => done.\n"
}

container_auth()
{
    printf "#### container_auth(): setting authentification... \n"
    if [[ "${user}" != "root" ]]; then
        printf " non root user requested, creating... \n"
        chroot "${rootfs}" useradd --create-home -s /bin/bash "${user}" || die 1 "failed to create user ${user}"
        printf "  => user %s created\n" "${user}"
    fi
    store_user_message "Connection user is ${user}"
    #Home of user
    auth_home=$(chroot "${rootfs}" getent passwd "${user}" | cut -d : -f 6)
    if [[ -r "${auth_key}" ]]; then
        printf " deploying auth_key %s for user %s ...\n" "${auth_key}" "${user}"
        mkdir -p "${rootfs}/${auth_home}/.ssh"
        cat "${auth_key}" >> "${rootfs}/${auth_home}/.ssh/authorized_keys"
        chroot "${rootfs}" chown "${user}:" "${auth_home}/.ssh/authorized_keys"
        printf "  => inserted public key in %s/.ssh/authorized_keys\n" "${auth_home}"
        [[ -z "${forced_password}" ]] && unset password
        store_user_message "${user} has the ssh key you gave us"
    fi

    if [[ -n "${password}" ]]; then
        printf " setting password for %s ...\n" "${user}"
        echo "${user}:${password}" | chroot "${rootfs}" chpasswd || die 1 "failed to change password"
        printf "  => done. if you didn't specify , default is 'toor'\n"
        if [[ -n "${forced_password}" ]]; then
            store_user_message "${user} has the password you give for him"
        fi
    fi

    printf " => done.\n"
}

container_sshd() {
    printf "#### container_sshd(): enabling sshd... \n"

    chroot "${rootfs}" rc-update add sshd || die 1 "failed to enable sshd\n"

    printf " => done.\n"
}

################################################################################
#                        lxc configuration files
################################################################################

container_conf()
{
    printf "container_configuration(): making lxc configuration file... \n"

    #at this point if there
    conf_file="${path}/config"

    # if there is exactly one veth network entry, make sure it has an
    # associated hwaddr.
    nics=`grep -e '^lxc\.net\.0\.type[ \t]*=[ \t]*veth' ${conf_file} | wc -l`
    if [ $nics -eq 1 ]; then
        grep -q "^lxc.net.0.hwaddr" ${conf_file} || sed -i -e "/^lxc\.net\.0\.type[ \t]*=[ \t]*veth/a lxc.net.0.hwaddr = 00:16:3e:$(openssl rand -hex 3| sed 's/\(..\)/\1:/g; s/.$//')" ${conf_file}
    fi

    if grep -q "^lxc.rootfs.path" "${conf_file}" ; then
        #lxc-create already provided one
        conf_rootfs_line=""
    else
        conf_rootfs_line="lxc.rootfs.path = $(readlink -f "${rootfs}")"
    fi
    if [[ "${arch}" == "x86" || "${arch}" == "amd64" ]]; then
        local conf_arch_line="lxc.arch = ${arch}"
    else
        local conf_arch_line="# lxc.arch = ${arch}"
    fi

    cat <<- EOF >> "${conf_file}"
# sets container architecture
# If desired architecture != amd64 or x86, then we leave it unset as
# LXC does not oficially support anything other than x86 or amd64.
${conf_arch_line}

# set the hostname
lxc.uts.name = ${name}
lxc.tty.max = ${tty}

${conf_rootfs_line}
${portage_mount}
${conf_sysfs}
${conf_mounts}

lxc.include = ${LXC_TEMPLATE_CONFIG}/gentoo.${settings}.conf
EOF
    printf  " => done.\n"
}

usage()
{
    cat <<EOF
$1 -h|--help [-a|--arch <arch>] [-v|--variant <variant>] [-P|--private-portage] [--portage-dir <protagedir>] [-t|--tarball <stage3file>]
 [-F|--flush-cache] [-c|--cache-only] [-u|--user <username>] [-w|--password <password>] [--autologin] [-S|--auth-key <keyfile>]
 [-s|--settings <name>] [-m|--mirror <gentoomirror>] [--tty <number>]

arch: the container architecture (e.g. amd64): defaults to host arch (currently: '${arch}')
    If you choose one that needs emulation
    tested: amd64, x86
    You could try any other gentoo arch, why not...

variant: gentoo's Architecture variant as of dec 2013 : (currently: '${variant}')
    for amd64 arch: amd64 (default), amd64-hardened+nomultilib, amd64-hardened, amd64-nomultilib, x32
    for x86 arch: i686 (default), i486, i686-hardened
    for arm arch: armv7a (default), armv7a_hardfp, armv6j, armv6j_hardfp, armv5tel, armv4tl

private-portage: by default, /usr/portage is mount-binded with host one if exists (currently: '${private_portage}')
    this force container to have his own copy

portage-dir: portage dir used for shared portage
    by default the host on if any (currently: '${portage_dir}')

tarball: force usage of local stage3 archive (currently: '${arch}')
    If empty, latest will be downloaded

flush-cache: do like there is no previous cache

cache-only: just ensure cache is present
    if cache exists and "flush-cache" not specified, does nothing

user: user used in auth oriented options (currently: '${user}')

password: password for user (currently: '${password}')
    if default, usage of auth-key will disable password setting

autologin: enable autologin for user (currently: '${autologin}')
    This unset default password setting

auth-key: SSH Public key file to inject into container for user (currently: '${auth_key}')
    This unset default password setting

settings: choose common configuration (currently: '${settings}')
    see ${LXC_TEMPLATE_CONFIG}/gentoo.*.conf
    Available settings:
    $(ls -1 ${LXC_TEMPLATE_CONFIG}/gentoo.*.conf | xargs basename -a -s .conf | sed 's/^gentoo.//')

mirror: gentoo mirror for download (currently: '${mirror}')

tty: number of tty (6 max) (currently: '${tty}')
EOF
    exit 0
}

#some overridable defaults
set_default_arch

mirror="http://distfiles.gentoo.org"
user="root"
tty=1
settings="common"
options=$(getopt -o hp:n:a:FcPv:t:S:u:w:s:m: -l help,rootfs:,path:,name:,arch:,flush-cache,cache-only,private-portage,variant:,portage-dir:,tarball:,auth-key:,user:,autologin,password:,settings:,mirror:,tty: -- "$@")

eval set -- "$options"

while true
do
    case "$1" in
    -h|--help)             usage $0 && exit 0;;
    --rootfs)              rootfs=$2; shift 2;;
    -p|--path)             path=$2; shift 2;;
    -n|--name)             name=$2; shift 2;;
    -a|--arch)             arch=$2; shift 2;;
    -F|--flush-cache)      flush_cache=1; shift 1;;
    -c|--cache-only)       cache_only=1; shift 1;;
    -P|--private-portage)  private_portage=1; shift 1;;
    -v|--variant)          variant=$2; shift 2;;
    --portage-dir)         portage_dir=$2; shift 2;;
    -t|--tarball)          tarball=$2; shift 2;;
    -S|--auth-key)         auth_key=$2; shift 2;;
    -u|--user)             user=$2; shift 2;;
    -w|--password)         forced_password=1; password=$2; shift 2;;
    -s|--settings)         settings=$2; shift 2;;
    -m|--mirror)           mirror=$2; shift 2;;
    --container-cache)  containercache=$2; shift 2;;
    --tty)                 [[ $2 -lt 6 ]] && tty=$2; shift 2;;
    --autologin)            autologin=1; shift 1;;
    --) shift 1; break ;;
    *)           break ;;
    esac
done

# Allow the cache path to be set by environment variable
cacheroot="${LXC_CACHE_PATH:-"@LOCALSTATEDIR@/cache/lxc"}/gentoo"
portage_cache="${cacheroot}/portage.tbz"
cachefs="${cacheroot}/rootfs-${arch}-${variant}"

alias wget="wget --timeout=8 --read-timeout=15 -c -t10 -nd"

do_all() {
    cache_setup
    if [ -z "${cache_only}" ]; then
        container_setup
    fi
}

execute_exclusively "cache-${arch}-${variant}" 60 do_all