#!/bin/bash

#
# template script for generating OpenSUSE container for LXC
#

#
# lxc: linux Container library

# Authors:
# Daniel Lezcano <daniel.lezcano@free.fr>
# Frederic Crozat <fcrozat@suse.com>
# Michael H. Warfield <mhw@WittsEnd.com>
# Johannes Kastl <mail@ojkastl.de>

# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.

# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# Lesser General Public License for more details.

# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

# 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

configure_opensuse()
{
    rootfs=$1
    hostname=$2

   # set first network adapter as dhcp.  This is the most common config.
   cat <<EOF > $rootfs/etc/sysconfig/network/ifcfg-eth0
STARTMODE='auto'
BOOTPROTO='dhcp'
EOF

   # create empty fstab
   touch $rootfs/etc/fstab

    # set the hostname
    cat <<EOF > $rootfs/etc/HOSTNAME
$hostname
EOF
    # ensure /etc/hostname is available too
    ln -s -f HOSTNAME $rootfs/etc/hostname

    # do not use hostname from HOSTNAME variable
    cat <<EOF >> $rootfs/etc/sysconfig/cron
unset HOSTNAME
EOF

    # set minimal hosts
    cat <<EOF > $rootfs/etc/hosts
127.0.0.1 localhost $hostname
EOF

    # disable yast->bootloader in container
    cat <<EOF > $rootfs/etc/sysconfig/bootloader
LOADER_TYPE=none
LOADER_LOCATION=none
EOF

    # set /dev/console as securetty
    cat << EOF >> $rootfs/etc/securetty
console
EOF

    cat <<EOF >> $rootfs/etc/sysconfig/boot
# disable root fsck
ROOTFS_FSCK="0"
ROOTFS_BLKDEV="/dev/null"
EOF


    # remove pointless services in a container
    ln -s /dev/null $rootfs/etc/systemd/system/proc-sys-fs-binfmt_misc.automount
    ln -s /dev/null $rootfs/etc/systemd/system/console-shell.service
    ln -s /dev/null $rootfs/etc/systemd/system/systemd-vconsole-setup.service
    sed -e 's/ConditionPathExists=.*//' /usr/lib/systemd/system/getty@.service > $rootfs/etc/systemd/system/getty@.service
    ln -s getty@.service $rootfs/etc/systemd/system/getty@tty1.service
    ln -s ../getty@.service $rootfs/etc/systemd/system/getty.target.wants/getty@console.service
    ln -s -f ../getty@.service $rootfs/etc/systemd/system/getty.target.wants/getty@tty1.service
    ln -s ../getty@.service $rootfs/etc/systemd/system/getty.target.wants/getty@tty2.service
    ln -s ../getty@.service $rootfs/etc/systemd/system/getty.target.wants/getty@tty3.service
    ln -s ../getty@.service $rootfs/etc/systemd/system/getty.target.wants/getty@tty4.service

    # copy host poweroff target as sigpwr target to make shutdown work
    # see https://wiki.archlinux.org/index.php/Linux_Containers#Container_cannot_be_shutdown_if_using_systemd
    cp /usr/lib/systemd/system/poweroff.target $rootfs/usr/lib/systemd/system/sigpwr.target

    touch $rootfs/etc/sysconfig/kernel

    echo "Please change root-password !"
    echo "root:root" | chpasswd -R $rootfs

    return 0
}

download_opensuse()
{
    cache=$1
    arch=$2

    if [ ! -x /usr/bin/build ]; then
       echo "Could not create openSUSE template :"
       echo "you need to install \"build\" package"
       return 1
    fi

    # check the mini opensuse was not already downloaded
    mkdir -p "$cache/partial-$arch"

    if [ $? -ne 0 ]; then
        echo "Failed to create '$cache/partial-$arch' directory"
        return 1
    fi

    # download a mini opensuse into a cache
    echo "Downloading opensuse minimal ..."
    mkdir -p "$cache/partial-$arch-packages"
    zypper --quiet --root $cache/partial-$arch-packages --non-interactive ar http://download.opensuse.org/distribution/$DISTRO/repo/oss/ repo-oss || return 1
    zypper --quiet --root $cache/partial-$arch-packages --non-interactive ar http://download.opensuse.org/update/$DISTRO/ update || return 1
    zypper --quiet --root $cache/partial-$arch-packages --non-interactive --gpg-auto-import-keys update || return 1
    zypper --root $cache/partial-$arch-packages --non-interactive in --auto-agree-with-licenses --download-only zypper lxc patterns-openSUSE-base bash iputils sed tar rsyslog || return 1
    cat > $cache/partial-$arch-packages/opensuse.conf << EOF
Preinstall: aaa_base bash coreutils diffutils
Preinstall: filesystem fillup glibc grep insserv-compat perl-base
Preinstall: libbz2-1 libgcc_s1 libncurses5 pam
Preinstall: permissions libreadline6 rpm sed tar libz1 libselinux1
Preinstall: liblzma5 libcap2 libacl1 libattr1
Preinstall: libpopt0 libelf1 liblua5_1
Preinstall: libpcre1

RunScripts: aaa_base

Support: zypper
Support: patterns-openSUSE-base
Support: lxc
Support: ncurses-utils
Support: iputils
Support: udev
Support: netcfg
Support: dhcpcd hwinfo insserv-compat module-init-tools openSUSE-release openssh
Support: pwdutils rpcbind sysconfig

Ignore: rpm:suse-build-key,build-key
Ignore: systemd:systemd-presets-branding
EOF

    if [ $DISTRO = "13.2" ]
    then
	echo "Support: python3-base" >> $cache/partial-$arch-packages/opensuse.conf
    fi

    if [ "$arch" = "i686" ]; then
        mkdir -p $cache/partial-$arch-packages/var/cache/zypp/packages/repo-oss/suse/i686/
        for i in "$cache/partial-$arch-packages/var/cache/zypp/packages/repo-oss/suse/i586/*" ; do
            ln -s $i $cache/partial-$arch-packages/var/cache/zypp/packages/repo-oss/suse/i686/
        done
        mkdir -p $cache/partial-$arch-packages/var/cache/zypp/packages/update/i686
        for i in "$cache/partial-$arch-packages/var/cache/zypp/packages/update/i586/*" ; do
            ln -s $i $cache/partial-$arch-packages/var/cache/zypp/packages/update/i686/
        done
    fi

    # openSUSE 13.2 has no noarch directory in update
    [ -d $cache/partial-$arch-packages/var/cache/zypp/packages/update/noarch ] || mkdir -p $cache/partial-$arch-packages/var/cache/zypp/packages/update/noarch

    CLEAN_BUILD=1 BUILD_ARCH="$arch" BUILD_ROOT="$cache/partial-$arch" BUILD_DIST="$cache/partial-$arch-packages/opensuse.conf" PATH="$PATH:/usr/lib/build" /usr/lib/build/init_buildsystem  --clean --configdir /usr/lib/build/configs --cachedir $cache/partial-$arch-cache --repository $cache/partial-$arch-packages/var/cache/zypp/packages/repo-oss/suse/$arch --repository $cache/partial-$arch-packages/var/cache/zypp/packages/repo-oss/suse/noarch --repository $cache/partial-$arch-packages/var/cache/zypp/packages/update/$arch --repository $cache/partial-$arch-packages/var/cache/zypp/packages/update/noarch || return 1
    chroot $cache/partial-$arch /usr/bin/zypper --quiet --non-interactive ar http://download.opensuse.org/distribution/$DISTRO/repo/oss repo-oss || return 1
    chroot $cache/partial-$arch /usr/bin/zypper --quiet --non-interactive ar http://download.opensuse.org/update/$DISTRO/ update || return 1
#   really clean the image
    rm -fr $cache/partial-$arch/{.build,.guessed_dist,.srcfiles*,installed-pkg}
    rm -fr $cache/partial-$arch/dev
#    make sure we have a minimal /dev
    mkdir -p "$cache/partial-$arch/dev"
    mknod -m 666 $cache/partial-$arch/dev/null c 1 3
    mknod -m 666 $cache/partial-$arch/dev/zero c 1 5
#   create mtab symlink
    rm -f $cache/partial-$arch/etc/mtab
    ln -sf /proc/self/mounts $cache/partial-$arch/etc/mtab

# ensure /var/run and /run are symlinked
    rm -fr $cache/partial-$arch/var/run
    ln -s -f ../run $cache/partial-$arch/var/run
    if [ $? -ne 0 ]; then
        echo "Failed to download the rootfs, aborting."
        return 1
    fi

    rm -fr "$cache/partial-$arch-packages"
    mv "$1/partial-$arch" "$1/rootfs-$arch"
    echo "Download complete."

    return 0
}

copy_opensuse()
{
    cache=$1
    arch=$2
    rootfs=$3

    # make a local copy of the mini opensuse
    echo "Copying rootfs to $rootfs ..."
    mkdir -p $rootfs
    rsync -Ha $cache/rootfs-$arch/ $rootfs/ || return 1
    return 0
}

install_opensuse()
{
    cache="@LOCALSTATEDIR@/cache/lxc/opensuse/$DISTRO"
    rootfs=$1
    mkdir -p @LOCALSTATEDIR@/lock/subsys/
    (
        flock -x 9
        if [ $? -ne 0 ]; then
            echo "Cache repository is busy."
            return 1
        fi

        echo "Checking cache download in $cache/rootfs-$arch ... "
        if [ ! -e "$cache/rootfs-$arch" ]; then
            download_opensuse $cache $arch
            if [ $? -ne 0 ]; then
                echo "Failed to download 'opensuse base'"
                return 1
            fi
        fi

        echo "Copy $cache/rootfs-$arch to $rootfs ... "
        copy_opensuse $cache $arch $rootfs
        if [ $? -ne 0 ]; then
            echo "Failed to copy rootfs"
            return 1
        fi

        return 0
    ) 9>@LOCALSTATEDIR@/lock/subsys/lxc-opensuse

    return $?
}

# Generate a random hardware (MAC) address composed of FE followed by
# 5 random bytes...
create_hwaddr()
{
    openssl rand -hex 5 | sed -e 's/\(..\)/:\1/g; s/^/fe/'
}

copy_configuration()
{
    path=$1
    rootfs=$2
    name=$3

    grep -q "^lxc.rootfs" $path/config 2>/dev/null || echo "
lxc.rootfs = $rootfs_path
" >> $path/config

    # The following code is to create static MAC addresses for each
    # interface in the container.  This code will work for multiple
    # interfaces in the default config.  It will also strip any
    # hwaddr stanzas out of the default config since we can not share
    # MAC addresses between containers.
    #
    # This code is largely mimiced from the Fedora Template.
    mv $path/config $path/config.def
    while read LINE
    do
        # This should catch variable expansions from the default config...
        if expr "${LINE}" : '.*\$' > /dev/null 2>&1
        then
                LINE=$(eval "echo \"${LINE}\"")
        fi

        # There is a tab and a space in the regex bracket below!
        # Seems that \s doesn't work in brackets.
        KEY=$(expr "${LINE}" : '\s*\([^	 ]*\)\s*=')

        if [[ "${KEY}" != "lxc.network.hwaddr" ]]
        then
            echo "${LINE}" >> $path/config

            if [[ "${KEY}" == "lxc.network.link" ]]
            then
                echo "lxc.network.hwaddr = $(create_hwaddr)" >> $path/config
            fi
        fi
    done < $path/config.def

    rm -f $path/config.def

    if [ -e "@LXCTEMPLATECONFIG@/opensuse.common.conf" ]; then
        echo "
# Include common configuration
lxc.include = @LXCTEMPLATECONFIG@/opensuse.common.conf
" >> $path/config
    fi

    # Append things which require expansion here...
    cat <<EOF >> $path/config
lxc.arch = $arch
lxc.utsname = $name

lxc.mount.auto = cgroup:mixed proc:mixed sys:mixed

# When using LXC with apparmor, uncomment the next line to run unconfined:
#lxc.aa_profile = unconfined

# example simple networking setup, uncomment to enable
#lxc.network.type = $lxc_network_type
#lxc.network.flags = up
#lxc.network.link = $lxc_network_link
#lxc.network.name = eth0
# Additional example for veth network type
#    static MAC address,
#lxc.network.hwaddr = 00:16:3e:77:52:20
#    persistent veth device name on host side
#        Note: This may potentially collide with other containers of same name!
#lxc.network.veth.pair = v-$name-e0

EOF

    if [ $? -ne 0 ]; then
        echo "Failed to add configuration"
        return 1
    fi

    return 0
}

clean()
{
    cache="@LOCALSTATEDIR@/cache/lxc/opensuse"

    if [ ! -e $cache ]; then
        exit 0
    fi

    # lock, so we won't purge while someone is creating a repository
    (
        flock -x 9
        if [ $? != 0 ]; then
            echo "Cache repository is busy."
            exit 1
        fi

        echo -n "Purging the download cache..."
        rm --preserve-root --one-file-system -rf $cache && echo "Done." || exit 1
        exit 0
    ) 9>@LOCALSTATEDIR@/lock/subsys/lxc-opensuse
}

usage()
{
    cat <<EOF
$1 -h|--help -p|--path=<path> -r|--release nn.n --clean
Please give the release as 13.1, 13.2 etc.
If no release is given, openSUSE 13.1 is installed.
EOF
    return 0
}

# Make arch a global.  This may become configurable?
arch=$(uname -m)

options=$(getopt -o hp:n:r:c -l help,rootfs:,path:,name:,release:,clean -- "$@")
if [ $? -ne 0 ]; then
    usage $(basename $0)
    exit 1
fi
eval set -- "$options"

while true
do
    case "$1" in
        -h|--help)      usage $0 && exit 0;;
        -p|--path)      path=$2; shift 2;;
        --rootfs)       rootfs=$2; shift 2;;
        -n|--name)      name=$2; shift 2;;
        -r|--release)   DISTRO=$2; shift 2;;
        -c|--clean)     clean=1; shift 1;;
        --)             shift 1; break ;;
        *)              break ;;
    esac
done

if [ ! -z "$clean" -a -z "$path" ]; then
    clean || exit 1
    exit 0
fi

type zypper > /dev/null
if [ $? -ne 0 ]; then
    echo "'zypper' command is missing"
    exit 1
fi

if [ -z "$path" ]; then
    echo "'path' parameter is required"
    exit 1
fi

if grep -q Harlequin /etc/os-release || grep -q Tumbleweed /etc/os-release ; then
    if [[ "$(zypper info build|awk -F "[- ]" '/Version/ {print $2}')" -lt "20141120" ]] ; then
	echo "Building openSUSE containers with your version of the build package is broken. Please install the update to version 20141120 or newer."
	exit 1
    fi
fi

if [ -z "$DISTRO" ]; then
    echo ""
    echo "No release selected, using openSUSE 13.1"
    DISTRO=13.1
else
    echo ""
    case "$DISTRO" in
	13.1)
	    echo "Selected openSUSE 13.1"
	    ;;

	13.2)
	    echo "Selected openSUSE 13.2"
	    ;;

	*)
	    echo "You have chosen an invalid release, quitting..."
	    exit 1
	    ;;
    esac
fi


if [ "$(id -u)" != "0" ]; then
    echo "This script should be run as 'root'"
    exit 1
fi

# detect rootfs
config="$path/config"
if [ -z "$rootfs" ]; then
    if grep -q '^lxc.rootfs' $config 2>/dev/null ; then
        rootfs=$(awk -F= '/^lxc.rootfs =/{ print $2 }' $config)
    else
        rootfs=$path/rootfs
    fi
fi

install_opensuse $rootfs
if [ $? -ne 0 ]; then
    echo "failed to install opensuse"
    exit 1
fi

configure_opensuse $rootfs $name
if [ $? -ne 0 ]; then
    echo "failed to configure opensuse for a container"
    exit 1
fi

copy_configuration $path $rootfs $name
if [ $? -ne 0 ]; then
    echo "failed write configuration file"
    exit 1
fi

if [ ! -z "$clean" ]; then
    clean || exit 1
    exit 0
fi