apatil/lxc-sense

## lxc-sense
#!/bin/bash

#
# template script for generating container for LXC
# with username and password 'sense'
# and an ssh key for the root user.
#
# This script consolidates and extends the existing lxc ubuntu scripts
#

# Copyright (c) 2011 Serge Hallyn <serge.hallyn@canonical.com>
# Copyright (c) 2010 Wilhelm Meier
# Author: Wilhelm Meier <wilhelm.meier@fh-kl.de>
# Modified by Anand Patil
#
# 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

configure_ubuntu()
{
    rootfs=$1
    hostname=$2
    release=$3

   # configure the network using the dhcp
    cat <<EOF > $rootfs/etc/network/interfaces
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

# The loopback network interface
auto lo
iface lo inet loopback

auto eth0
iface eth0 inet dhcp
EOF

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

# The following lines are desirable for IPv6 capable hosts
::1     ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
EOF

    if [ ! -f $rootfs/etc/init/container-detect.conf ]; then
        # suppress log level output for udev
        sed -i "s/=\"err\"/=0/" $rootfs/etc/udev/udev.conf

        # remove jobs for consoles 5 and 6 since we only create 4 consoles in
        # this template
        rm -f $rootfs/etc/init/tty{5,6}.conf
    fi

    if [ -z "$bindhome" ]; then
        chroot $rootfs useradd --create-home -s /bin/bash sense
        echo "sense:sense" | chroot $rootfs chpasswd
    fi

    return 0
}

# finish setting up the user in the container by injecting ssh key and
# adding sudo group membership.
# passed-in user is either 'sense' or the user to bind in from host.
finalize_user()
{
    user=$1

    sudo_version=$(chroot $rootfs dpkg-query -W -f='${Version}' sudo)

    # Uncomment this to grant the 'sense' user sudo access.
    #if chroot $rootfs dpkg --compare-versions $sudo_version gt "1.8.3p1-1"; then
        #groups="sudo"
    #else
        #groups="sudo admin"
    #fi
#
    #for group in $groups; do
        #chroot $rootfs groupadd --system $group >/dev/null 2>&1 || true
        #chroot $rootfs adduser ${user} $group >/dev/null 2>&1 || true
    #done

    if [ -n "$root_key" -a -f "$root_key" ]; then
        u_path="/root/.ssh"
        root_u_path="$rootfs/$u_path"

        mkdir -p $root_u_path
        cp $root_key "$root_u_path/authorized_keys"
        chroot $rootfs chown -R root: "$u_path"

        echo "Inserted SSH public key from $root_key into /root/.ssh/authorized_keys"
    fi

    if [ -n "$user_key" -a -f "$user_key" ]; then
        u_path="/home/sense/.ssh"
        root_u_path="$rootfs/$u_path"

        mkdir -p $root_u_path
        cp $user_key "$root_u_path/authorized_keys"
        chroot $rootfs chown -R sense: "$u_path"

        echo "Inserted SSH public key from $user_key into /home/sense/.ssh/authorized_keys"
    fi

    return 0
}

write_sourceslist()
{
    # $1 => path to the rootfs
    # $2 => architecture we want to add
    # $3 => whether to use the multi-arch syntax or not

    case $2 in
      amd64|i386)
            MIRROR=${MIRROR:-http://archive.ubuntu.com/ubuntu}
            SECURITY_MIRROR=${SECURITY_MIRROR:-http://security.ubuntu.com/ubuntu}
            ;;
      *)
            MIRROR=${MIRROR:-http://ports.ubuntu.com/ubuntu-ports}
            SECURITY_MIRROR=${SECURITY_MIRROR:-http://ports.ubuntu.com/ubuntu-ports}
            ;;
    esac
    if [ -n "$3" ]; then
        cat >> "$1/etc/apt/sources.list" << EOF
deb [arch=$2] $MIRROR ${release} main restricted universe multiverse
deb [arch=$2] $MIRROR ${release}-updates main restricted universe multiverse
deb [arch=$2] $SECURITY_MIRROR ${release}-security main restricted universe multiverse
EOF
    else
        cat >> "$1/etc/apt/sources.list" << EOF
deb $MIRROR ${release} main restricted universe multiverse
deb $MIRROR ${release}-updates main restricted universe multiverse
deb $SECURITY_MIRROR ${release}-security main restricted universe multiverse
EOF
    fi
}

cleanup()
{
    rm -rf $cache/partial-$arch
    rm -rf $cache/rootfs-$arch
}

suggest_flush()
{
    echo "Container upgrade failed.  The container cache may be out of date,"
    echo "in which case flushing the case (see -F in the hep output) may help."
}

download_ubuntu()
{
    cache=$1
    arch=$2
    release=$3

    packages=vim,ssh
    echo "installing packages: $packages"

    trap cleanup EXIT SIGHUP SIGINT SIGTERM
    # check the mini ubuntu 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 ubuntu into a cache
    echo "Downloading ubuntu $release minimal ..."
    if [ -n "$(which qemu-debootstrap)" ]; then
        qemu-debootstrap --verbose --components=main,universe --arch=$arch --include=$packages $release $cache/partial-$arch $MIRROR
    else
        debootstrap --verbose --components=main,universe --arch=$arch --include=$packages $release $cache/partial-$arch $MIRROR
    fi

    if [ $? -ne 0 ]; then
        echo "Failed to download the rootfs, aborting."
            return 1
    fi

    # Serge isn't sure whether we should avoid doing this when
    # $release == `distro-info -d`
    echo "Installing updates"
    > $cache/partial-$arch/etc/apt/sources.list
    write_sourceslist $cache/partial-$arch/ $arch

    chroot "$1/partial-${arch}" apt-get update
    if [ $? -ne 0 ]; then
        echo "Failed to update the apt cache"
        return 1
    fi
    cat > "$1/partial-${arch}"/usr/sbin/policy-rc.d << EOF
#!/bin/sh
exit 101
EOF
    chmod +x "$1/partial-${arch}"/usr/sbin/policy-rc.d

    lxc-unshare -s MOUNT -- chroot "$1/partial-${arch}" apt-get dist-upgrade -y || { suggest_flush; false; }
    rm -f "$1/partial-${arch}"/usr/sbin/policy-rc.d

    chroot "$1/partial-${arch}" apt-get clean

    mv "$1/partial-$arch" "$1/rootfs-$arch"
    trap EXIT
    trap SIGINT
    trap SIGTERM
    trap SIGHUP
    echo "Download complete"
    return 0
}

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

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

install_ubuntu()
{
    rootfs=$1
    release=$2
    flushcache=$3
    cache="/var/cache/lxc/$release"
    mkdir -p /var/lock/subsys/

    (
        flock -x 200
        if [ $? -ne 0 ]; then
            echo "Cache repository is busy."
            return 1
        fi


        if [ $flushcache -eq 1 ]; then
            echo "Flushing cache..."
            rm -rf "$cache/partial-$arch"
            rm -rf "$cache/rootfs-$arch"
        fi

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

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

        return 0

    ) 200>/var/lock/subsys/lxc

    return $?
}

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

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

    ttydir=""
    if [ -f $rootfs/etc/init/container-detect.conf ]; then
        ttydir=" lxc"
    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

    grep -q "^lxc.rootfs" $path/config 2>/dev/null || echo "lxc.rootfs = $rootfs" >> $path/config
    cat <<EOF >> $path/config
lxc.utsname = $name

lxc.devttydir =$ttydir
lxc.tty = 4
lxc.pts = 1024
lxc.mount  = $path/fstab
lxc.arch = $arch
lxc.cap.drop = sys_module mac_admin mac_override
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

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

    return 0
}

trim()
{
    rootfs=$1
    release=$2

    # provide the lxc service
    cat <<EOF > $rootfs/etc/init/lxc.conf
# fake some events needed for correct startup other services

description     "Container Upstart"

start on startup

script
        rm -rf /var/run/*.pid
        rm -rf /var/run/network/*
        /sbin/initctl emit stopped JOB=udevtrigger --no-wait
        /sbin/initctl emit started JOB=udev --no-wait
end script
EOF

    # fix buggus runlevel with sshd
    cat <<EOF > $rootfs/etc/init/ssh.conf
# ssh - OpenBSD Secure Shell server
#
# The OpenSSH server provides secure shell access to the system.

description	"OpenSSH server"

start on filesystem
stop on runlevel [!2345]

expect fork
respawn
respawn limit 10 5
umask 022
# replaces SSHD_OOM_ADJUST in /etc/default/ssh
oom never

pre-start script
    test -x /usr/sbin/sshd || { stop; exit 0; }
    test -e /etc/ssh/sshd_not_to_be_run && { stop; exit 0; }
    test -c /dev/null || { stop; exit 0; }

    mkdir -p -m0755 /var/run/sshd
end script

# if you used to set SSHD_OPTS in /etc/default/ssh, you can change the
# 'exec' line here instead
exec /usr/sbin/sshd
EOF

    cat <<EOF > $rootfs/etc/init/console.conf
# console - getty
#
# This service maintains a console on tty1 from the point the system is
# started until it is shut down again.

start on stopped rc RUNLEVEL=[2345]
stop on runlevel [!2345]

respawn
exec /sbin/getty -8 38400 /dev/console
EOF

    cat <<EOF > $rootfs/lib/init/fstab
# /lib/init/fstab: cleared out for bare-bones lxc
EOF

    # reconfigure some services
    if [ -z "$LANG" ]; then
        chroot $rootfs locale-gen en_US.UTF-8
        chroot $rootfs update-locale LANG=en_US.UTF-8
    else
        chroot $rootfs locale-gen $LANG
        chroot $rootfs update-locale LANG=$LANG
    fi

    # remove pointless services in a container
    chroot $rootfs /usr/sbin/update-rc.d -f ondemand remove

    chroot $rootfs /bin/bash -c 'cd /etc/init; for f in $(ls u*.conf); do mv $f $f.orig; done'
    chroot $rootfs /bin/bash -c 'cd /etc/init; for f in $(ls tty[2-9].conf); do mv $f $f.orig; done'
    chroot $rootfs /bin/bash -c 'cd /etc/init; for f in $(ls plymouth*.conf); do mv $f $f.orig; done'
    chroot $rootfs /bin/bash -c 'cd /etc/init; for f in $(ls hwclock*.conf); do mv $f $f.orig; done'
    chroot $rootfs /bin/bash -c 'cd /etc/init; for f in $(ls module*.conf); do mv $f $f.orig; done'

    # if this isn't lucid, then we need to twiddle the network upstart bits :(
    if [ $release != "lucid" ]; then
        sed -i 's/^.*emission handled.*$/echo Emitting lo/' $rootfs/etc/network/if-up.d/upstart
    fi
}

post_process()
{
    rootfs=$1
    release=$2
    trim_container=$3

    if [ $trim_container -eq 1 ]; then
        trim $rootfs $release
    elif [ ! -f $rootfs/etc/init/container-detect.conf ]; then
        # Make sure we have a working resolv.conf
        cresolvonf="${rootfs}/etc/resolv.conf"
        mv $cresolvonf ${cresolvonf}.lxcbak
        cat /etc/resolv.conf > ${cresolvonf}

        # for lucid, if not trimming, then add the ubuntu-virt
        # ppa and install lxcguest
        if [ $release = "lucid" ]; then
            chroot $rootfs apt-get update
            chroot $rootfs apt-get install --force-yes -y python-software-properties
            chroot $rootfs add-apt-repository ppa:ubuntu-virt/ppa
        fi

        chroot $rootfs apt-get update
        chroot $rootfs apt-get install --force-yes -y lxcguest

        # Restore old resolv.conf
        rm -f ${cresolvonf}
        mv ${cresolvonf}.lxcbak ${cresolvonf}
    fi

    # If the container isn't running a native architecture, setup multiarch
    if [ -x "$(ls -1 ${rootfs}/usr/bin/qemu-*-static 2>/dev/null)" ]; then
        dpkg_version=$(chroot $rootfs dpkg-query -W -f='${Version}' dpkg)
        if chroot $rootfs dpkg --compare-versions $dpkg_version ge "1.16.2"; then
            chroot $rootfs dpkg --add-architecture ${hostarch}
        else
            mkdir -p ${rootfs}/etc/dpkg/dpkg.cfg.d
            echo "foreign-architecture ${hostarch}" > ${rootfs}/etc/dpkg/dpkg.cfg.d/lxc-multiarch
        fi

        # Save existing value of MIRROR and SECURITY_MIRROR
        DEFAULT_MIRROR=$MIRROR
        DEFAULT_SECURITY_MIRROR=$SECURITY_MIRROR

        # Write a new sources.list containing both native and multiarch entries
        > ${rootfs}/etc/apt/sources.list
        write_sourceslist $rootfs $arch "native"

        MIRROR=$DEFAULT_MIRROR
        SECURITY_MIRROR=$DEFAULT_SECURITY_MIRROR
        write_sourceslist $rootfs $hostarch "multiarch"

        # Finally update the lists and install upstart using the host architecture
        chroot $rootfs apt-get update
        chroot $rootfs apt-get install --force-yes -y --no-install-recommends upstart:${hostarch} mountall:${hostarch} iproute:${hostarch} isc-dhcp-client:${hostarch}
    fi

    # rmdir /dev/shm for containers that have /run/shm
    # 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 [ ! -L $rootfs/dev/shm ] && [ -d $rootfs/run/shm ] && [ -e $rootfs/dev/shm ]; then
        mv $rootfs/dev/shm $rootfs/dev/shm.bak
        ln -s /run/shm $rootfs/dev/shm
    fi
}

do_bindhome()
{
    rootfs=$1
    user=$2

    # copy /etc/passwd, /etc/shadow, and /etc/group entries into container
    pwd=`getent passwd $user` || { echo "Failed to copy password entry for $user"; false; }
    echo $pwd >> $rootfs/etc/passwd

    # make sure user's shell exists in the container
    shell=`echo $pwd | cut -d: -f 7`
    if [ ! -x $rootfs/$shell ]; then
        echo "shell $shell for user $user was not found in the container."
        pkg=`dpkg -S $(readlink -m $shell) | cut -d ':' -f1`
        echo "Installing $pkg"
        chroot $rootfs apt-get --force-yes -y install $pkg
    fi

    shad=`getent shadow $user`
    echo "$shad" >> $rootfs/etc/shadow

    # bind-mount the user's path into the container's /home
    h=`getent passwd $user | cut -d: -f 6`
    mkdir -p $rootfs/$h

    # use relative path in container
    h2=${h#/}
    while [ ${h2:0:1} = "/" ]; do
        h2=${h2#/}
    done
    echo "$h $h2 none bind 0 0" >> $path/fstab

    # Make sure the group exists in container
    grp=`echo $pwd | cut -d: -f 4`  # group number for $user
    grpe=`getent group $grp` || return 0  # if host doesn't define grp, ignore in container
    chroot $rootfs getent group "$grpe" || echo "$grpe" >> $rootfs/etc/group
}

usage()
{
    cat <<EOF
$1 -h|--help [-a|--arch] [-b|--bindhome <user>] [--trim] [-d|--debug]
   [-F | --flush-cache] [-r|--release <release>] [ -R | --root-key <keyfile>] [ -U | --user-key <keyfile>]
release: the ubuntu release (e.g. precise): defaults to host release on ubuntu, otherwise uses latest LTS
trim: make a minimal (faster, but not upgrade-safe) container
bindhome: bind <user>'s home into the container
          The sense user will not be created, and <user> will have
          sudo access.
arch: the container architecture (e.g. amd64): defaults to host arch
root-key: SSH Public key file to inject into container for root user
EOF
    return 0
}

options=$(getopt -o a:b:hp:r:xn:FR:U:d -l arch:,bindhome:,help,path:,release:,trim,name:,flush-cache,root-key:,user-key:,debug -- "$@")
if [ $? -ne 0 ]; then
    usage $(basename $0)
    exit 1
fi
eval set -- "$options"

release=precise # Default to the last Ubuntu LTS release for non-Ubuntu systems
if [ -f /etc/lsb-release ]; then
    . /etc/lsb-release
    if [ "$DISTRIB_ID" = "Ubuntu" ]; then
        release=$DISTRIB_CODENAME
    fi
fi

bindhome=
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
        arch="armel"
    fi
fi

debug=0
trim_container=0
hostarch=$arch
flushcache=0
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;;
    -b|--bindhome)  bindhome=$2; shift 2;;
    -a|--arch)      arch=$2; shift 2;;
    -x|--trim)      trim_container=1; shift 1;;
    -R|--root-key)  root_key=$2; shift 2;;
    -U|--user-key)  user_key=$2; shift 2;;
    -d|--debug)     debug=1; shift 1;;
    --)             shift 1; break ;;
        *)              break ;;
    esac
done

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

if [ -n "$bindhome" ]; then
    pwd=`getent passwd $bindhome`
    if [ $? -ne 0 ]; then
        echo "Error: no password entry found for $bindhome"
        exit 1
    fi
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

type debootstrap
if [ $? -ne 0 ]; then
    echo "'debootstrap' command is missing"
    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

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

install_ubuntu $rootfs $release $flushcache
if [ $? -ne 0 ]; then
    echo "failed to install ubuntu $release"
    exit 1
fi

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

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

post_process $rootfs $release $trim_container

if [ -n "$bindhome" ]; then
    do_bindhome $rootfs $bindhome
    finalize_user $bindhome
else
    finalize_user sense
fi

echo ""
echo "##"
if [ -n "$bindhome" ]; then
	echo "# Log in as user $bindhome"
else
	echo "# The default user is 'sense' with password 'sense'!"
	echo "# Use the 'sudo' command to run tasks as root in the container."
fi
echo "##"
echo ""
	#!/bin/bash

	#
	# template script for generating container for LXC
	# with username and password 'sense'
	# and an ssh key for the root user.
	#
	# This script consolidates and extends the existing lxc ubuntu scripts
	#

	# Copyright (c) 2011 Serge Hallyn <serge.hallyn@canonical.com>
	# Copyright (c) 2010 Wilhelm Meier
	# Author: Wilhelm Meier <wilhelm.meier@fh-kl.de>
	# Modified by Anand Patil
	#
	# 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

	configure_ubuntu()
	{
	rootfs=$1
	hostname=$2
	release=$3

	# configure the network using the dhcp
	cat <<EOF > $rootfs/etc/network/interfaces
	# This file describes the network interfaces available on your system
	# and how to activate them. For more information, see interfaces(5).

	# The loopback network interface
	auto lo
	iface lo inet loopback

	auto eth0
	iface eth0 inet dhcp
	EOF

	# set the hostname
	cat <<EOF > $rootfs/etc/hostname
	$hostname
	EOF
	# set minimal hosts
	cat <<EOF > $rootfs/etc/hosts
	127.0.0.1 localhost
	127.0.1.1 $hostname

	# The following lines are desirable for IPv6 capable hosts
	::1 ip6-localhost ip6-loopback
	fe00::0 ip6-localnet
	ff00::0 ip6-mcastprefix
	ff02::1 ip6-allnodes
	ff02::2 ip6-allrouters
	EOF

	if [ ! -f $rootfs/etc/init/container-detect.conf ]; then
	# suppress log level output for udev
	sed -i "s/=\"err\"/=0/" $rootfs/etc/udev/udev.conf

	# remove jobs for consoles 5 and 6 since we only create 4 consoles in
	# this template
	rm -f $rootfs/etc/init/tty{5,6}.conf
	fi

	if [ -z "$bindhome" ]; then
	chroot $rootfs useradd --create-home -s /bin/bash sense
	echo "sense:sense" \| chroot $rootfs chpasswd
	fi

	return 0
	}

	# finish setting up the user in the container by injecting ssh key and
	# adding sudo group membership.
	# passed-in user is either 'sense' or the user to bind in from host.
	finalize_user()
	{
	user=$1

	sudo_version=$(chroot $rootfs dpkg-query -W -f='${Version}' sudo)

	# Uncomment this to grant the 'sense' user sudo access.
	#if chroot $rootfs dpkg --compare-versions $sudo_version gt "1.8.3p1-1"; then
	#groups="sudo"
	#else
	#groups="sudo admin"
	#fi
	#
	#for group in $groups; do
	#chroot $rootfs groupadd --system $group >/dev/null 2>&1 \|\| true
	#chroot $rootfs adduser ${user} $group >/dev/null 2>&1 \|\| true
	#done

	if [ -n "$root_key" -a -f "$root_key" ]; then
	u_path="/root/.ssh"
	root_u_path="$rootfs/$u_path"

	mkdir -p $root_u_path
	cp $root_key "$root_u_path/authorized_keys"
	chroot $rootfs chown -R root: "$u_path"

	echo "Inserted SSH public key from $root_key into /root/.ssh/authorized_keys"
	fi

	if [ -n "$user_key" -a -f "$user_key" ]; then
	u_path="/home/sense/.ssh"
	root_u_path="$rootfs/$u_path"

	mkdir -p $root_u_path
	cp $user_key "$root_u_path/authorized_keys"
	chroot $rootfs chown -R sense: "$u_path"

	echo "Inserted SSH public key from $user_key into /home/sense/.ssh/authorized_keys"
	fi

	return 0
	}

	write_sourceslist()
	{
	# $1 => path to the rootfs
	# $2 => architecture we want to add
	# $3 => whether to use the multi-arch syntax or not

	case $2 in
	amd64\|i386)
	MIRROR=${MIRROR:-http://archive.ubuntu.com/ubuntu}
	SECURITY_MIRROR=${SECURITY_MIRROR:-http://security.ubuntu.com/ubuntu}
	;;
	*)
	MIRROR=${MIRROR:-http://ports.ubuntu.com/ubuntu-ports}
	SECURITY_MIRROR=${SECURITY_MIRROR:-http://ports.ubuntu.com/ubuntu-ports}
	;;
	esac
	if [ -n "$3" ]; then
	cat >> "$1/etc/apt/sources.list" << EOF
	deb [arch=$2] $MIRROR ${release} main restricted universe multiverse
	deb [arch=$2] $MIRROR ${release}-updates main restricted universe multiverse
	deb [arch=$2] $SECURITY_MIRROR ${release}-security main restricted universe multiverse
	EOF
	else
	cat >> "$1/etc/apt/sources.list" << EOF
	deb $MIRROR ${release} main restricted universe multiverse
	deb $MIRROR ${release}-updates main restricted universe multiverse
	deb $SECURITY_MIRROR ${release}-security main restricted universe multiverse
	EOF
	fi
	}

	cleanup()
	{
	rm -rf $cache/partial-$arch
	rm -rf $cache/rootfs-$arch
	}

	suggest_flush()
	{
	echo "Container upgrade failed. The container cache may be out of date,"
	echo "in which case flushing the case (see -F in the hep output) may help."
	}

	download_ubuntu()
	{
	cache=$1
	arch=$2
	release=$3

	packages=vim,ssh
	echo "installing packages: $packages"

	trap cleanup EXIT SIGHUP SIGINT SIGTERM
	# check the mini ubuntu 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 ubuntu into a cache
	echo "Downloading ubuntu $release minimal ..."
	if [ -n "$(which qemu-debootstrap)" ]; then
	qemu-debootstrap --verbose --components=main,universe --arch=$arch --include=$packages $release $cache/partial-$arch $MIRROR
	else
	debootstrap --verbose --components=main,universe --arch=$arch --include=$packages $release $cache/partial-$arch $MIRROR
	fi

	if [ $? -ne 0 ]; then
	echo "Failed to download the rootfs, aborting."
	return 1
	fi

	# Serge isn't sure whether we should avoid doing this when
	# $release == `distro-info -d`
	echo "Installing updates"
	> $cache/partial-$arch/etc/apt/sources.list
	write_sourceslist $cache/partial-$arch/ $arch

	chroot "$1/partial-${arch}" apt-get update
	if [ $? -ne 0 ]; then
	echo "Failed to update the apt cache"
	return 1
	fi
	cat > "$1/partial-${arch}"/usr/sbin/policy-rc.d << EOF
	#!/bin/sh
	exit 101
	EOF
	chmod +x "$1/partial-${arch}"/usr/sbin/policy-rc.d

	lxc-unshare -s MOUNT -- chroot "$1/partial-${arch}" apt-get dist-upgrade -y \|\| { suggest_flush; false; }
	rm -f "$1/partial-${arch}"/usr/sbin/policy-rc.d

	chroot "$1/partial-${arch}" apt-get clean

	mv "$1/partial-$arch" "$1/rootfs-$arch"
	trap EXIT
	trap SIGINT
	trap SIGTERM
	trap SIGHUP
	echo "Download complete"
	return 0
	}

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

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

	install_ubuntu()
	{
	rootfs=$1
	release=$2
	flushcache=$3
	cache="/var/cache/lxc/$release"
	mkdir -p /var/lock/subsys/

	(
	flock -x 200
	if [ $? -ne 0 ]; then
	echo "Cache repository is busy."
	return 1
	fi


	if [ $flushcache -eq 1 ]; then
	echo "Flushing cache..."
	rm -rf "$cache/partial-$arch"
	rm -rf "$cache/rootfs-$arch"
	fi

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

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

	return 0

	) 200>/var/lock/subsys/lxc

	return $?
	}

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

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

	ttydir=""
	if [ -f $rootfs/etc/init/container-detect.conf ]; then
	ttydir=" lxc"
	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

	grep -q "^lxc.rootfs" $path/config 2>/dev/null \|\| echo "lxc.rootfs = $rootfs" >> $path/config
	cat <<EOF >> $path/config
	lxc.utsname = $name

	lxc.devttydir =$ttydir
	lxc.tty = 4
	lxc.pts = 1024
	lxc.mount = $path/fstab
	lxc.arch = $arch
	lxc.cap.drop = sys_module mac_admin mac_override
	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

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

	return 0
	}

	trim()
	{
	rootfs=$1
	release=$2

	# provide the lxc service
	cat <<EOF > $rootfs/etc/init/lxc.conf
	# fake some events needed for correct startup other services

	description "Container Upstart"

	start on startup

	script
	rm -rf /var/run/*.pid
	rm -rf /var/run/network/*
	/sbin/initctl emit stopped JOB=udevtrigger --no-wait
	/sbin/initctl emit started JOB=udev --no-wait
	end script
	EOF

	# fix buggus runlevel with sshd
	cat <<EOF > $rootfs/etc/init/ssh.conf
	# ssh - OpenBSD Secure Shell server
	#
	# The OpenSSH server provides secure shell access to the system.

	description "OpenSSH server"

	start on filesystem
	stop on runlevel [!2345]

	expect fork
	respawn
	respawn limit 10 5
	umask 022
	# replaces SSHD_OOM_ADJUST in /etc/default/ssh
	oom never

	pre-start script
	test -x /usr/sbin/sshd \|\| { stop; exit 0; }
	test -e /etc/ssh/sshd_not_to_be_run && { stop; exit 0; }
	test -c /dev/null \|\| { stop; exit 0; }

	mkdir -p -m0755 /var/run/sshd
	end script

	# if you used to set SSHD_OPTS in /etc/default/ssh, you can change the
	# 'exec' line here instead
	exec /usr/sbin/sshd
	EOF

	cat <<EOF > $rootfs/etc/init/console.conf
	# console - getty
	#
	# This service maintains a console on tty1 from the point the system is
	# started until it is shut down again.

	start on stopped rc RUNLEVEL=[2345]
	stop on runlevel [!2345]

	respawn
	exec /sbin/getty -8 38400 /dev/console
	EOF

	cat <<EOF > $rootfs/lib/init/fstab
	# /lib/init/fstab: cleared out for bare-bones lxc
	EOF

	# reconfigure some services
	if [ -z "$LANG" ]; then
	chroot $rootfs locale-gen en_US.UTF-8
	chroot $rootfs update-locale LANG=en_US.UTF-8
	else
	chroot $rootfs locale-gen $LANG
	chroot $rootfs update-locale LANG=$LANG
	fi

	# remove pointless services in a container
	chroot $rootfs /usr/sbin/update-rc.d -f ondemand remove

	chroot $rootfs /bin/bash -c 'cd /etc/init; for f in $(ls u*.conf); do mv $f $f.orig; done'
	chroot $rootfs /bin/bash -c 'cd /etc/init; for f in $(ls tty[2-9].conf); do mv $f $f.orig; done'
	chroot $rootfs /bin/bash -c 'cd /etc/init; for f in $(ls plymouth*.conf); do mv $f $f.orig; done'
	chroot $rootfs /bin/bash -c 'cd /etc/init; for f in $(ls hwclock*.conf); do mv $f $f.orig; done'
	chroot $rootfs /bin/bash -c 'cd /etc/init; for f in $(ls module*.conf); do mv $f $f.orig; done'

	# if this isn't lucid, then we need to twiddle the network upstart bits :(
	if [ $release != "lucid" ]; then
	sed -i 's/^.emission handled.$/echo Emitting lo/' $rootfs/etc/network/if-up.d/upstart
	fi
	}

	post_process()
	{
	rootfs=$1
	release=$2
	trim_container=$3

	if [ $trim_container -eq 1 ]; then
	trim $rootfs $release
	elif [ ! -f $rootfs/etc/init/container-detect.conf ]; then
	# Make sure we have a working resolv.conf
	cresolvonf="${rootfs}/etc/resolv.conf"
	mv $cresolvonf ${cresolvonf}.lxcbak
	cat /etc/resolv.conf > ${cresolvonf}

	# for lucid, if not trimming, then add the ubuntu-virt
	# ppa and install lxcguest
	if [ $release = "lucid" ]; then
	chroot $rootfs apt-get update
	chroot $rootfs apt-get install --force-yes -y python-software-properties
	chroot $rootfs add-apt-repository ppa:ubuntu-virt/ppa
	fi

	chroot $rootfs apt-get update
	chroot $rootfs apt-get install --force-yes -y lxcguest

	# Restore old resolv.conf
	rm -f ${cresolvonf}
	mv ${cresolvonf}.lxcbak ${cresolvonf}
	fi

	# If the container isn't running a native architecture, setup multiarch
	if [ -x "$(ls -1 ${rootfs}/usr/bin/qemu-*-static 2>/dev/null)" ]; then
	dpkg_version=$(chroot $rootfs dpkg-query -W -f='${Version}' dpkg)
	if chroot $rootfs dpkg --compare-versions $dpkg_version ge "1.16.2"; then
	chroot $rootfs dpkg --add-architecture ${hostarch}
	else
	mkdir -p ${rootfs}/etc/dpkg/dpkg.cfg.d
	echo "foreign-architecture ${hostarch}" > ${rootfs}/etc/dpkg/dpkg.cfg.d/lxc-multiarch
	fi

	# Save existing value of MIRROR and SECURITY_MIRROR
	DEFAULT_MIRROR=$MIRROR
	DEFAULT_SECURITY_MIRROR=$SECURITY_MIRROR

	# Write a new sources.list containing both native and multiarch entries
	> ${rootfs}/etc/apt/sources.list
	write_sourceslist $rootfs $arch "native"

	MIRROR=$DEFAULT_MIRROR
	SECURITY_MIRROR=$DEFAULT_SECURITY_MIRROR
	write_sourceslist $rootfs $hostarch "multiarch"

	# Finally update the lists and install upstart using the host architecture
	chroot $rootfs apt-get update
	chroot $rootfs apt-get install --force-yes -y --no-install-recommends upstart:${hostarch} mountall:${hostarch} iproute:${hostarch} isc-dhcp-client:${hostarch}
	fi

	# rmdir /dev/shm for containers that have /run/shm
	# 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 [ ! -L $rootfs/dev/shm ] && [ -d $rootfs/run/shm ] && [ -e $rootfs/dev/shm ]; then
	mv $rootfs/dev/shm $rootfs/dev/shm.bak
	ln -s /run/shm $rootfs/dev/shm
	fi
	}

	do_bindhome()
	{
	rootfs=$1
	user=$2

	# copy /etc/passwd, /etc/shadow, and /etc/group entries into container
	pwd=`getent passwd $user` \|\| { echo "Failed to copy password entry for $user"; false; }
	echo $pwd >> $rootfs/etc/passwd

	# make sure user's shell exists in the container
	shell=`echo $pwd \| cut -d: -f 7`
	if [ ! -x $rootfs/$shell ]; then
	echo "shell $shell for user $user was not found in the container."
	pkg=`dpkg -S $(readlink -m $shell) \| cut -d ':' -f1`
	echo "Installing $pkg"
	chroot $rootfs apt-get --force-yes -y install $pkg
	fi

	shad=`getent shadow $user`
	echo "$shad" >> $rootfs/etc/shadow

	# bind-mount the user's path into the container's /home
	h=`getent passwd $user \| cut -d: -f 6`
	mkdir -p $rootfs/$h

	# use relative path in container
	h2=${h#/}
	while [ ${h2:0:1} = "/" ]; do
	h2=${h2#/}
	done
	echo "$h $h2 none bind 0 0" >> $path/fstab

	# Make sure the group exists in container
	grp=`echo $pwd \| cut -d: -f 4` # group number for $user
	grpe=`getent group $grp` \|\| return 0 # if host doesn't define grp, ignore in container
	chroot $rootfs getent group "$grpe" \|\| echo "$grpe" >> $rootfs/etc/group
	}

	usage()
	{
	cat <<EOF
	$1 -h\|--help [-a\|--arch] [-b\|--bindhome <user>] [--trim] [-d\|--debug]
	[-F \| --flush-cache] [-r\|--release <release>] [ -R \| --root-key <keyfile>] [ -U \| --user-key <keyfile>]
	release: the ubuntu release (e.g. precise): defaults to host release on ubuntu, otherwise uses latest LTS
	trim: make a minimal (faster, but not upgrade-safe) container
	bindhome: bind <user>'s home into the container
	The sense user will not be created, and <user> will have
	sudo access.
	arch: the container architecture (e.g. amd64): defaults to host arch
	root-key: SSH Public key file to inject into container for root user
	EOF
	return 0
	}

	options=$(getopt -o a:b:hp:r:xn:FR:U:d -l arch:,bindhome:,help,path:,release:,trim,name:,flush-cache,root-key:,user-key:,debug -- "$@")
	if [ $? -ne 0 ]; then
	usage $(basename $0)
	exit 1
	fi
	eval set -- "$options"

	release=precise # Default to the last Ubuntu LTS release for non-Ubuntu systems
	if [ -f /etc/lsb-release ]; then
	. /etc/lsb-release
	if [ "$DISTRIB_ID" = "Ubuntu" ]; then
	release=$DISTRIB_CODENAME
	fi
	fi

	bindhome=
	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
	arch="armel"
	fi
	fi

	debug=0
	trim_container=0
	hostarch=$arch
	flushcache=0
	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;;
	-b\|--bindhome) bindhome=$2; shift 2;;
	-a\|--arch) arch=$2; shift 2;;
	-x\|--trim) trim_container=1; shift 1;;
	-R\|--root-key) root_key=$2; shift 2;;
	-U\|--user-key) user_key=$2; shift 2;;
	-d\|--debug) debug=1; shift 1;;
	--) shift 1; break ;;
	*) break ;;
	esac
	done

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

	if [ -n "$bindhome" ]; then
	pwd=`getent passwd $bindhome`
	if [ $? -ne 0 ]; then
	echo "Error: no password entry found for $bindhome"
	exit 1
	fi
	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

	type debootstrap
	if [ $? -ne 0 ]; then
	echo "'debootstrap' command is missing"
	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

	# detect rootfs
	config="$path/config"
	if grep -q '^lxc.rootfs' $config 2>/dev/null ; then
	rootfs=`grep 'lxc.rootfs =' $config \| awk -F= '{ print $2 }'`
	else
	rootfs=$path/rootfs
	fi

	install_ubuntu $rootfs $release $flushcache
	if [ $? -ne 0 ]; then
	echo "failed to install ubuntu $release"
	exit 1
	fi

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

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

	post_process $rootfs $release $trim_container

	if [ -n "$bindhome" ]; then
	do_bindhome $rootfs $bindhome
	finalize_user $bindhome
	else
	finalize_user sense
	fi

	echo ""
	echo "##"
	if [ -n "$bindhome" ]; then
	echo "# Log in as user $bindhome"
	else
	echo "# The default user is 'sense' with password 'sense'!"
	echo "# Use the 'sudo' command to run tasks as root in the container."
	fi
	echo "##"
	echo ""