#!/bin/bash

# This is a modified version of /usr/share/lxc/templates/lxc-debian
# that comes with Ubuntu 13.04 changed to suit vagrant-lxc needs

set -e

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

SUITE=${SUITE:-wheezy}
MIRROR=${MIRROR:-http://ftp.debian.org/debian}

configure_debian()
{
    rootfs=$1
    hostname=$2
    release=$2

    # squeeze only has /dev/tty and /dev/tty0 by default,
    # therefore creating missing device nodes for tty1-4.
    for tty in $(seq 1 4); do
        if [ ! -e $rootfs/dev/tty$tty ]; then
            mknod $rootfs/dev/tty$tty c 4 $tty
        fi
    done

    # configure the inittab
    cat <<EOF > $rootfs/etc/inittab
id:3:initdefault:
si::sysinit:/etc/init.d/rcS
l0:0:wait:/etc/init.d/rc 0
l1:1:wait:/etc/init.d/rc 1
l2:2:wait:/etc/init.d/rc 2
l3:3:wait:/etc/init.d/rc 3
l4:4:wait:/etc/init.d/rc 4
l5:5:wait:/etc/init.d/rc 5
l6:6:wait:/etc/init.d/rc 6
# Normally not reached, but fallthrough in case of emergency.
z6:6:respawn:/sbin/sulogin
1:2345:respawn:/sbin/getty 38400 console
#c1:12345:respawn:/sbin/getty 38400 tty1 linux
c2:12345:respawn:/sbin/getty 38400 tty2 linux
c3:12345:respawn:/sbin/getty 38400 tty3 linux
c4:12345:respawn:/sbin/getty 38400 tty4 linux
p6::ctrlaltdel:/sbin/init 6
p0::powerfail:/sbin/init 0
EOF

    # disable selinux in debian
    mkdir -p $rootfs/selinux
    echo 0 > $rootfs/selinux/enforce

    # configure the network using the dhcp
    cat <<EOF > $rootfs/etc/network/interfaces
auto lo
iface lo inet loopback

auto eth0
iface eth0 inet dhcp
EOF

    # set the hostname
    cat <<EOF > $rootfs/etc/hostname
$hostname
EOF

    # set the host in case it is not set so that sudo does not complain about the host
    if ! (grep -q $hostname $rootfs/etc/hosts); then
      chroot $rootfs sed -i -e \
          "s/^127.0.0.1\(\s\+\)localhost$/127.0.0.1\1localhost\n127.0.1.1\1${hostname}/g" \
          /etc/hosts >/dev/null 2>&1 || true
    fi

    # set default locale
    cat <<EOF > $rootfs/etc/locale.gen
en_US.UTF-8 UTF-8
EOF
    echo "default locale set to en_US.UTF-8 UTF-8"
    chroot $rootfs locale-gen 'en_US.UTF-8' > /dev/null 2>&1
    chroot $rootfs update-locale LANG='en_US.UTF-8'
    echo 'update-locale done'

    # remove pointless services in a container
    chroot $rootfs /usr/sbin/update-rc.d -f checkroot.sh remove
    chroot $rootfs /usr/sbin/update-rc.d -f umountfs remove
    chroot $rootfs /usr/sbin/update-rc.d -f hwclock.sh remove
    chroot $rootfs /usr/sbin/update-rc.d -f hwclockfirst.sh remove

    echo "root:vagrant" | chroot $rootfs chpasswd

    if ! (grep -q vagrant $rootfs/etc/passwd); then
      chroot $rootfs useradd --create-home -s /bin/bash vagrant
      echo "vagrant:vagrant" | chroot $rootfs chpasswd
      chroot $rootfs adduser vagrant sudo >/dev/null 2>&1 || true
      chroot $rootfs cp /etc/sudoers /etc/sudoers.orig >/dev/null 2>&1 || true
      chroot $rootfs sed -i -e \
          's/%sudo\s\+ALL=(ALL\(:ALL\)\?)\s\+ALL/%sudo ALL=NOPASSWD:ALL/g' \
          /etc/sudoers >/dev/null 2>&1 || true
    fi

    return 0
}

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

extract_rootfs()
{
    tarball=$1
    arch=$2
    rootfs=$3

    echo "Extracting $tarball ..."
    mkdir -p $(dirname $rootfs)
    (cd `dirname $rootfs` && tar xfz $tarball)
    return 0
}

install_debian()
{
    rootfs=$1
    release=$2
    tarball=$3
    mkdir -p /var/lock/subsys/

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

        extract_rootfs $tarball $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

    # 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.tty = 4
lxc.pts = 1024
lxc.utsname = ${name}

# When using LXC with apparmor, uncomment the next line to run 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

# mounts point
lxc.mount.entry = proc proc proc nodev,noexec,nosuid 0 0
lxc.mount.entry = sysfs sys sysfs defaults  0 0
EOF

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

}


add_ssh_key()
{
    user=$1

    if [ -n "$auth_key" -a -f "$auth_key" ]; then
        u_path="/home/${user}/.ssh"
        root_u_path="$rootfs/$u_path"

        mkdir -p $root_u_path
        cp $auth_key "$root_u_path/authorized_keys"
        chroot $rootfs chown -R ${user}: "$u_path"

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

disable_tmp_cleanup() {
    rootfs=$1
    chroot $rootfs /usr/sbin/update-rc.d -f checkroot-bootclean.sh remove
    chroot $rootfs /usr/sbin/update-rc.d -f mountall-bootclean.sh remove
    chroot $rootfs /usr/sbin/update-rc.d -f mountnfs-bootclean.sh remove
}

usage()
{
    cat <<EOF
$1 -h|--help [-a|--arch] [-d|--debug]
  [-F | --flush-cache] [-r|--release <release>] [ -S | --auth-key <keyfile>]
release: the debian release (e.g. wheezy): defaults to host release on debian, otherwise uses latest stable
arch: the container architecture (e.g. amd64): defaults to host arch
auth-key: SSH Public key file to inject into container
EOF
    return 0
}

options=$(getopt -o a:b:hp:r:xn:Fd:C -l arch:,help,path:,release:,name:,flush-cache,auth-key:,debug:,tarball: -- "$@")
if [ $? -ne 0 ]; then
    usage $(basename $0)
    exit 1
fi
eval set -- "$options"

release=wheezy  # Default to the last Debian stable release

arch=$(uname -m)

# 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=$(uname -m)
    if [ "$arch" = "i686" ]; then
        arch="i386"
    elif [ "$arch" = "x86_64" ]; then
        arch="amd64"
    elif [ "$arch" = "armv7l" ]; then
        arch="armel"
    fi
fi

debug=0
hostarch=$arch
while true
do
    case "$1" in
    -h|--help)      usage $0 && exit 0;;
    -p|--path)      path=$2; shift 2;;
    -n|--name)      name=$2; shift 2;;
    -T|--tarball)   tarball=$2; shift 2;;
    -r|--release)   release=$2; shift 2;;
    -S|--auth-key)  auth_key=$2; shift 2;;
    -a|--arch)      arch=$2; shift 2;;
    -d|--debug)     debug=1; shift 1;;
    --)             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 [ -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_debian $rootfs $release $tarball
if [ $? -ne 0 ]; then
    echo "failed to install debian $release"
    exit 1
fi

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

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

add_ssh_key vagrant

# vagrant and / or plugins might mount some shared folders under /tmp by default
# (like puppet manifests) and we need to make sure no shared folder gets its
# contents removed because of it. For more information, please check:
#   https://github.com/fgrehm/vagrant-lxc/issues/68
disable_tmp_cleanup $rootfs

echo ""
echo "##"
echo "# The default user is 'vagrant' with password 'vagrant'!"
echo "# Use the 'sudo' command to run tasks as root in the container."
echo "##"
echo ""