#!/bin/bash

#
# lxc: linux Container library

# Authors:
# Mike Friesenegger <mikef@suse.com>
# Daniel Lezcano <daniel.lezcano@free.fr>

# 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA


usage() {
    echo "usage: lxc-createconfig -n <name> [-i <ipaddr/cidr>] [-b <bridge>] [-t <template]"
}

help() {
    usage
    echo
    echo "creates a lxc container config file which can be in"
    echo "turn used by lxc-create to create the lxc system object."
    echo
    echo "Options:"
    echo "name         : name of the container"
    echo "ipaddr       : ip address/cidr of the container"
    echo "bridge       : bridge device for container (br0 if undefined)"
    echo "template     : template is an accessible template script (sles if undefined)"
}

shortoptions='hn:i:b:t:'
longoptions='help,name:,ipaddr:,bridge:,template:'
lxc_confpath=$HOME
templatedir=@LXCTEMPLATEDIR@
lxc_bridge=br0
lxc_template=sles

getopt=$(getopt -o $shortoptions --longoptions  $longoptions -- "$@")
if [ $? != 0 ]; then
    usage
    exit 1;
fi

eval set -- "$getopt"

while true; do
        case "$1" in
            -h|--help)
                help
                exit 1
                ;;
            -n|--name)
                shift
                lxc_name=$1
                lxc_confname=$lxc_name.config
                shift
                ;;
            -i|--ipaddr)
                shift
                lxc_ipaddr=$1
                shift
                ;;
            -b|--bridge)
                shift
                lxc_bridge=$1
                shift
                ;;
            -t|--template)
                shift
                lxc_template=$1
                shift
                ;;
            --)
                shift
                break;;
            *)
                echo $1
                usage
                exit 1
                ;;
        esac
done

if [ -z "$lxc_name" ]; then
    echo "no container name specified"
    usage
    exit 1
fi

if [ -f "$lxc_confpath/$lxc_confname" ]; then
    echo "'$lxc_confname' already exists"
    exit 1
fi

if [ ! -z "$lxc_ipaddr" ]; then
    echo $lxc_ipaddr | grep -E '/(([^C9]{0,1}[0-9])|(3[0-2]))$'
    if [ $? -ne 0 ]; then
        echo "$lxc_ipaddr is missing a cidr"
        usage
        exit 1
    fi
fi

if [ -z "$lxc_ipaddr" ]; then
    lxc_ipaddr=DHCP
fi

if [ ! -z $lxc_bridge ]; then
    brctl show | grep $lxc_bridge >/dev/null
    if [ $? -ne 0 ]; then
        echo "$lxc_bridge not defined"
        exit 1
    fi
fi

if [ ! -z $lxc_template ]; then
    type ${templatedir}/lxc-$lxc_template >/dev/null
    if [ $? -ne 0 ]; then
        echo "unknown template '$lxc_template'"
        exit 1
    fi
fi

echo
echo "Container Name            = " $lxc_name
echo "IP Address                = " $lxc_ipaddr
echo "Bridge                    = " $lxc_bridge
echo
echo -n "Create container config? (n): "
read ANSWER
if [ "$ANSWER" != "y" -a "$ANSWER" != "Y" ]
then
    exit 1
fi
echo
echo "Creating container config $lxc_confpath/$lxc_confname"

# generate a MAC for the IP
lxc_hwaddr="02:00:`(date ; cat /proc/interrupts ) | md5sum | sed -r 's/^(.{8}).*$/\1/;s/([0-9a-f]{2})/\1:/g;s/:$//;'`"

cat >"$lxc_confpath/$lxc_confname" <<%%
lxc.network.type = veth
lxc.network.flags = up
lxc.network.link = $lxc_bridge
lxc.network.hwaddr = $lxc_hwaddr
%%
if [ ! $lxc_ipaddr = "DHCP" ]; then
    cat >>"$lxc_confpath/$lxc_confname" <<%%
lxc.network.ipv4 = $lxc_ipaddr
%%
fi
cat >>"$lxc_confpath/$lxc_confname" <<%%
lxc.network.name = eth0
%%

echo
echo "Run 'lxc-create -n $lxc_name -f $lxc_confpath/$lxc_confname -t $lxc_template' to create the lxc system object."