#!/bin/bash
# -*- mode:shell-mode;tab-width:2;indent-tabs-mode:nil;coding:utf-8 -*-
# vim: ft=shell syn=shell fileencoding=utf-8 sw=2 ts=2 ai eol et si

# This is a modified version of /usr/share/lxc/templates/lxc-debian
# that comes with Ubuntu 12.10 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=$3

    # 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
EOF
    echo '/etc/inittab created'

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

    # 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
    echo 'network configured (dhcp on eth0)'


    # set the hostname
    cat <<EOF > $rootfs/etc/hostname
$hostname
EOF
    echo "/etc/hostname created (${hostname})"

    # set dhcp hostname
    cat <<EOF >> $rootfs/etc/dhcp/dhclient.conf
send host-name "$hostname";
EOF
    echo 'dhcp hostname set'

    if [ ! -z "${LANG}" ]; then
        # set default locale
        cat <<EOF > $rootfs/etc/locale.gen
${LANG} UTF-8
EOF
        echo "default locale set to ${LANG} UTF-8"
        chroot $rootfs locale-gen ${LANG} > /dev/null 2>&1
        chroot $rootfs update-locale LANG=${LANG}
        echo 'update-locale done'
    fi

    # set proxy if any
    if [ ! -z "${HTTP_PROXY}" ]; then
        cat <<EOF > $rootfs/etc/apt/apt.conf.d/10proxy
Acquire::http::Proxy "${HTTP_PROXY}";
Acquire::ftp::Proxy "${HTTP_PROXY}";
Acquire::ftp::Timeout "15";
Acquire::ftp::Passive "true";
Acquire::ftp::Proxy::Passive "true";
EOF
        echo "Apt default proxy set to ${HTTP_PROXY}"
        cat <<EOF >> $rootfs/etc/environment
HTTP_PROXY=${HTTP_PROXY}
HTTPS_PROXY=${HTTP_PROXY}
FTP_PROXY=${HTTP_PROXY}
EOF
        echo "proxy ${HTTP_PROXY} added to /etc/environment"
    fi

    # recommends are as of now still abused in many packages
    cat <<EOF > $rootfs/etc/apt/apt.conf.d/90recommends
APT::Install-Recommends "0";
APT::Install-Suggests "0";
EOF
    echo '/etc/apt/apt.conf.d/90recommends created'

    # set default release
    cat <<EOF > $rootfs/etc/apt/apt.conf.d/30release
DPkg::Default-Release "${release}";
APT::Default-Release "${release}";
EOF
    echo '/etc/apt/apt.conf.d/30release created'


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

    # remove pointless services in a container
    for service in checkroot \
                   umountfs \
                   hwclock.sh \
                   hwclockfirst.sh \
                   mountall.sh ; do
        chroot $rootfs /usr/sbin/update-rc.d -f $service remove > /dev/null 2>&1
        echo "service ${service} removed from init"
    done
    
    # suppress log level output for udev
    #sed -i "s/=\"err\"/=0/" $rootfs/etc/udev/udev.conf

    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 ${cache}/partial-${SUITE}-${arch}
    rm -rf ${cache}/rootfs-${SUITE}-${arch}
}

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

    echo "Extracting $tarball ..."
    mkdir -p $(dirname $rootfs)
    # Make sure the rootfs does not exist before extracting
    rm -rf $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
    arch=$4
    release=$5

    cat <<EOF >> $path/fstab
none $rootfs/dev/pts devpts defaults 0 0
none $rootfs/proc    proc   defaults 0 0
none $rootfs/sys     sysfs  defaults 0 0
none $rootfs/dev/shm tmpfs  defaults 0 0
EOF

    cat <<EOF >> $path/config
lxc.tty = 4
lxc.pts = 1024
lxc.rootfs = ${rootfs}
lxc.cgroup.devices.deny = a
# /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

# mounts point
#lxc.mount.entry=proc $rootfs/proc proc nodev,noexec,nosuid 0 0
#lxc.mount.entry=devpts $rootfs/dev/pts devpts defaults 0 0
#lxc.mount.entry=sysfs $rootfs/sys sysfs defaults  0 0
lxc.mount = ${path}/fstab

lxc.utsname = ${name}

# networking

lxc.network.type = veth
lxc.network.flags = up
# Bridged network
#lxc.network.link = br42
lxc.network.name = eth0
# It is fine to be commented out
# Warn: interface name 'vethXXXX' too long (>15)
#lxc.network.veth.pair = veth${name#*-}
#lxc.network.ipv4 = 10.1.1.1/24
#lxc.network.hwaddr = 00:12:34:56:78:9A
lxc.network.hwaddr = \
00:16:3e:$(openssl rand -hex 3| sed 's/\(..\)/\1:/g; s/.$//')

# Limits

# Set max memory
lxc.cgroup.memory.limit_in_bytes = 1024M

# Scheduler, works like this: You assign to vm0 the value of 10 and to vm1
# the value of 20. This means: in each CPU Second vm1 will get the double
# amount of CPU cycles as vm0. Per default all values are set to 1024.
#lxc.cgroup.cpu.shares = 512

# CPUs
# assign first CPU to this container:
#lxc.cgroup.cpuset.cpus = 0 
# assign the first, the second and the last CPU
#lxc.cgroup.cpuset.cpus = 0-1,3
# assign the first and the last CPU
#lxc.cgroup.cpuset.cpus = 0,3

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
}

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 $rootfs "vagrant-debian-${release}" $release
if [ $? -ne 0 ]; then
    echo "failed to configure debian $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

add_ssh_key vagrant

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 ""