#!/bin/bash

# template script for generating ubuntu container for LXC based on released cloud
# images
#
# Copyright © 2012 Serge Hallyn <serge.hallyn@canonical.com>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2, as
# published by the Free Software Foundation.

# This program 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 General Public License for more details.

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

set -e

if [ -r /etc/default/lxc ]; then
    . /etc/default/lxc
fi

copy_configuration()
{
    path=$1
    rootfs=$2
    name=$3
    arch=$4
    release=$5

    if [ $arch = "i386" ]; then
        arch="i686"
    fi

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

    cat <<EOF >> $path/config
lxc.utsname = $name

lxc.tty = 4
lxc.pts = 1024
lxc.rootfs = $rootfs
lxc.mount  = $path/fstab
lxc.arch = $arch
lxc.cap.drop = sys_module mac_admin
lxc.pivotdir = lxc_putold

# uncomment the next line to run the container unconfined:
#lxc.aa_profile = unconfined

lxc.cgroup.devices.deny = a
# Allow any mknod (but not using the node)
lxc.cgroup.devices.allow = c *:* m
lxc.cgroup.devices.allow = b *:* m
# /dev/null and zero
lxc.cgroup.devices.allow = c 1:3 rwm
lxc.cgroup.devices.allow = c 1:5 rwm
# consoles
lxc.cgroup.devices.allow = c 5:1 rwm
lxc.cgroup.devices.allow = c 5:0 rwm
#lxc.cgroup.devices.allow = c 4:0 rwm
#lxc.cgroup.devices.allow = c 4:1 rwm
# /dev/{,u}random
lxc.cgroup.devices.allow = c 1:9 rwm
lxc.cgroup.devices.allow = c 1:8 rwm
lxc.cgroup.devices.allow = c 136:* rwm
lxc.cgroup.devices.allow = c 5:2 rwm
# rtc
lxc.cgroup.devices.allow = c 254:0 rwm
#fuse
lxc.cgroup.devices.allow = c 10:229 rwm
#tun
lxc.cgroup.devices.allow = c 10:200 rwm
#full
lxc.cgroup.devices.allow = c 1:7 rwm
#hpet
lxc.cgroup.devices.allow = c 10:228 rwm
#kvm
lxc.cgroup.devices.allow = c 10:232 rwm
EOF

    cat <<EOF > $path/fstab
proc            proc         proc    nodev,noexec,nosuid 0 0
sysfs           sys          sysfs defaults  0 0
EOF

    # rmdir /dev/shm in precise and quantal containers.
    # I'm afraid of doing rm -rf $rootfs/dev/shm, in case it did
    # get bind mounted to the host's /run/shm.  So try to rmdir
    # it, and in case that fails move it out of the way.
    if [ $release = "precise" ] || [ $release = "quantal" ]; then
        [ -d "$rootfs/dev/shm" ] && rmdir $rootfs/dev/shm
        [ -e "$rootfs/dev/shm" ] && mv $rootfs/dev/shm $rootfs/dev/shm.bak
        ln -s /run/shm $rootfs/dev/shm
    fi

    return 0
}

usage()
{
    cat <<EOF
LXC Container configuration for Ubuntu Cloud images.

Generic Options
[ -r | --release <release> ]: Release name of container, defaults to host
[ -a | --arch ]: Arhcitecture of container, defaults to host arcitecture
[ -C | --cloud ]: Configure container for use with meta-data service, defaults to no
[ -T | --tarball ]: Location of tarball
[ -d | --debug ]: Run with 'set -x' to debug errors
[ -s | --stream]: Use specified stream rather than 'released'

Options, mutually exclusive of "-C" and "--cloud":
  [ -i | --hostid ]:    HostID for cloud-init, defaults to random string
  [ -u | --userdata ]:  Cloud-init user-data file to configure container on start
  [ -S | --auth-key ]:  SSH Public key file to inject into container
  [ -L | --nolocales ]: Do not copy host's locales into container

EOF
    return 0
}

options=$(getopt -o a:hp:r:n:Fi:CLS:T:ds: -l arch:,help,path:,release:,name:,flush-cache,hostid:,auth-key:,cloud,no_locales,tarball:,debug,stream:,userdata: -- "$@")
if [ $? -ne 0 ]; then
    usage $(basename $0)
    exit 1
fi
eval set -- "$options"

release=lucid
if [ -f /etc/lsb-release ]; then
    . /etc/lsb-release
    case "$DISTRIB_CODENAME" in
        lucid|natty|oneiric|precise|quantal)
            release=$DISTRIB_CODENAME
        ;;
    esac
fi

arch=$(arch)

# Code taken from debootstrap
if [ -x /usr/bin/dpkg ] && /usr/bin/dpkg --print-architecture >/dev/null 2>&1; then
    arch=`/usr/bin/dpkg --print-architecture`
elif type udpkg >/dev/null 2>&1 && udpkg --print-architecture >/dev/null 2>&1; then
    arch=`/usr/bin/udpkg --print-architecture`
else
    arch=$(arch)
    if [ "$arch" = "i686" ]; then
        arch="i386"
    elif [ "$arch" = "x86_64" ]; then
        arch="amd64"
    elif [ "$arch" = "armv7l" ]; then
        # note: arm images don't exist before oneiric;  are called armhf in
        # precise and later;  and are not supported by the query, so we don't actually
        # support them yet (see check later on).  When Query2 is available,
        # we'll use that to enable arm images.
        arch="armel"
    fi
fi

debug=0
hostarch=$arch
cloud=0
locales=1
flushcache=0
stream="released"
while true
do
    case "$1" in
    -h|--help)         usage $0 && exit 0;;
    -p|--path)         path=$2; shift 2;;
    -n|--name)         name=$2; shift 2;;
    -F|--flush-cache)  flushcache=1; shift 1;;
    -r|--release)      release=$2; shift 2;;
    -a|--arch)         arch=$2; shift 2;;
    -i|--hostid)       host_id=$2; shift 2;;
    -u|--userdata)     userdata=$2; shift 2;;
    -C|--cloud)        cloud=1; shift 1;;
    -S|--auth-key)     auth_key=$2; shift 2;;
    -L|--no_locales)   locales=0; shift 2;;
    -T|--tarball)      tarball=$2; shift 2;;
    -d|--debug)        debug=1; shift 1;;
    -s|--stream)       stream=$2; shift 2;;
    --)                shift 1; break ;;
        *)              break ;;
    esac
done

if [ $debug -eq 1 ]; then
    set -x
fi

if [ "$arch" == "i686" ]; then
    arch=i386
fi

if [ $hostarch = "i386" -a $arch = "amd64" ]; then
    echo "can't create amd64 container on i386"
    exit 1
fi

if [ $arch != "i386" -a $arch != "amd64" ]; then
    echo "Only i386 and amd64 are supported by the ubuntu cloud template."
    exit 1
fi

if [ "$stream" != "daily" -a "$stream" != "released" ]; then
    echo "Only 'daily' and 'released' streams are supported"
    exit 1
fi

if [ -n "$userdata" -a ! -f "$userdata" ]; then
    echo "Userdata does not exist"
    exit 1
fi

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

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

rootfs=$path/rootfs

type ubuntu-cloudimg-query
type wget

# determine the url, tarball, and directory names
# download if needed
cache="/var/cache/lxc/cloud-$release"

mkdir -p $cache

if [ -n "$tarball" ]; then
	url2="$tarball"
else
	url1=`ubuntu-cloudimg-query $release $stream $arch --format "%{url}\n"`
	url2=`echo $url1 | sed -e 's/.tar.gz/-root\0/'`
fi

filename=`basename $url2`

buildcleanup()
{
    cd $rootfs
    umount -l $cache/$xdir || true
    rm -rf $cache
}

# if the release doesn't have a *-rootfs.tar.gz, then create one from the
# cloudimg.tar.gz by extracting the .img, mounting it loopback, and creating
# a tarball from the mounted image.
build_root_tgz()
{
    url=$1
    filename=$2

    xdir=`mktemp -d -p .`
    tarname=`basename $url`
    imgname="$release-*-cloudimg-$arch.img"
    trap buildcleanup EXIT
    if [ $flushcache -eq 1 -o ! -f $cache/$tarname ]; then
        rm -f $tarname
        echo "Downloading cloud image from $url"
        wget $url || { echo "Couldn't find cloud image $url."; exit 1; }
    fi
    echo "Creating new cached cloud image rootfs"
    tar --wildcards -zxf $tarname $imgname
    mount -o loop $imgname $xdir
    (cd $xdir; tar zcf ../$filename .)
    umount $xdir
    rm -f $tarname $imgname
    rmdir $xdir
    echo "New cloud image cache created"
    trap EXIT
}

mkdir -p /var/lock/subsys/
(
    flock -x 200

    cd $cache
    if [ $flushcache -eq 1 ]; then
        echo "Clearing the cached images"
        rm -f $filename
    fi

    if [ ! -f $filename ]; then
       wget $url2 || build_root_tgz $url1 $filename
    fi

    echo "Extracting container rootfs"
    mkdir -p $rootfs
    cd $rootfs
    tar -zxf $cache/$filename


    if [ $cloud -eq 0 ]; then
	echo "Configuring for running outside of a cloud environment"
	echo "If you want to configure for a cloud evironment, please use '-- -C' to create the container"

	seed_d=$rootfs/var/lib/cloud/seed/nocloud-net
	rhostid=$(uuidgen | cut -c -8)
	host_id=${hostid:-$rhostid}
	mkdir -p $seed_d

	cat > "$seed_d/meta-data" <<EOF
instance_id: lxc-$host_id
EOF

	rm $rootfs/etc/hostname

	if [ $locales -eq 1 ]; then
		cp /usr/lib/locale/locale-archive $rootfs/usr/lib/locale/locale-archive
	fi


	if [ -n "$auth_key" -a -f "$auth_key" ]; then
		u_path="/home/ubuntu/.ssh"
		root_u_path="$rootfs/$u_path"
		mkdir -p $root_u_path
		cp $auth_key "$root_u_path/authorized_keys"
		chroot $rootfs chown -R ubuntu: "$u_path"

		echo "Inserted SSH public key from $auth_key into /home/ubuntu/.ssh/authorized_keys"
	fi

	if [ -f "$userdata" ]; then
		echo "Using custom user-data"
		cp $userdata $seed_d/user-data
	else

		if [ -z "$MIRROR" ]; then
			MIRROR="http://archive.ubuntu.com/ubuntu"
		fi

		cat > "$seed_d/user-data" <<EOF
#cloud-config
output: {all: '| tee -a /var/log/cloud-init-output.log'}
apt-mirror: $MIRROR
manage_etc_hosts: localhost
locale: $(/usr/bin/locale | awk -F= '/LANG=/ {print$NF}')
EOF
	fi

	chroot $rootfs /usr/sbin/usermod -U ubuntu
    	echo "ubuntu:ubuntu" | chroot $rootfs chpasswd
	echo "Please login as user ubuntu with password ubuntu."

   else

	echo "Configured for running in a cloud environment."
	echo "If you do not have a meta-data service, this container will likely be useless."

   fi

) 200>/var/lock/subsys/lxc-ubucloud

copy_configuration $path $rootfs $name $arch $release

echo "Container $name created."
exit 0
