#!/bin/bash
#
# Copyright (C) 2003, Mark Lawrence <nomad@null.net>
# Copyright (C) 2003, Paul Sladen <vserver@paul.sladen.org>
# Licence: GPL
#
# Install a virtual debian server (vserver) from a debian HTTP/FTP archive

version="20030207.1"
umask 022
me=${0##*/}


### Helper functions ###

exec 3>&1
exec 4>&2

noninteractive () {
	exec &> /dev/null
}

interactive () {
	exec 1>&3
	exec 2>&4
}


info () {
	echo "I: $1" >&3
}

warn () {
	echo "W: $1" >&4
}

error () {
	echo "E: $2" >&4
	exit $1
}


### Usage/Info functions ###

usage () {
    cat <<EOF 1>&2
Usage:	$me [-c config] [OPTIONS] hostname domain 1.2.3.4
	(see -h for help)
EOF
}

full_usage () {
        cat <<EOF
Usage:	$me [-c config] [OPTIONS] hostname domain 1.2.3.4

Creates a new Debian vserver by downloading packages via HTTP/FTP.

Options:
        -h, --help		this help
	-V, --version		copyright and version information
	-v, --verbose           show extra output during setup
	-c, --config [config]	use [config] for settings 
				(/etc/vservers/debserver by default)
	-a, --arch [i386]	set target architecture
	-d, --dist [woody]	passed to debootstrap.
	-f, --force		overwrite an existing vserver directory/conf
	    --install		list of packages to install (quoted with spaces)
	    --purge		list of packages to not install (as above)
	-i, --interface	[eth0]	interface to assign IP address to
	-k, --fakeinit		use "/sbin/init" to boot vserver
	-l, --localapt		copy roothost apt directory to vserver
	-m, --mirror [url]	Debian HTTP/FTP mirror (including the /debian)
	-r, --vsroot		location of "/vserver/" directory
	-s, --sshkeys [keyfile]	copy root host public ssh key to
				"/root/.ssh/authorized_keys" in vserver

EOF
}

full_version () {
    cat <<EOF
$me version $version
Copyright (C) 2003, Mark Lawrence <nomad@null.net>
Copyright (C) 2003, Paul Sladen <vserver@paul.sladen.org>.

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or (at
your option) any later version.

EOF
}

check_config () {

	if [ ! -x /usr/sbin/debootstrap ]; then
		info "Require the debootstrap package to bootstrap Debian"
		info "	Debian Host:  apt-get install debootstrap"
		info "  RPM Host:     rpm -i http://people.debian.org/~blade/install/debootstrap/debootstrap-0.1.17.3-2.i386.rpm"
		error 1 "Missing deboostrap"
	fi

	if [ ! -x /usr/bin/ar ]; then
		info "Require \"ar\" for debootstrap"
		info "	Debian Host: apt-get install binutils"
		error 1 "Missing ar command"
	fi

	if ! cat /proc/self/status | grep '^s_context:[^0-9]0$'; then
		info "Must be run from the host server (security context 0)"
		info "	on a "vserver/ctx-patch" enabled kernel"
		info "	See: http://www.solucorp.qc.ca/miscprj/s_context.hc"
		error 1 "Not running from a context 0 host"
	fi

	if [ -x /usr/bin/id ] && [ `id -u` -ne 0 ]; then
		error 1 "Must be run as root!"
	fi

	### Perform some sanity checks on the configuration ###

	hostname="$1"
	domain="$2"
	ip="$3"

	if ! (echo $hostname | grep -q '^[a-z][a-z0-9]\+'); then
		error 1 "$hostname is not a valid hostname"
	fi

	if ! (echo $domain | grep -q '^[a-z].*[a-z]$'); then
		error 1 "$domain is not a valid DNS domain"
	fi

	fqdn="$hostname.$domain"
	if ! (host $fqdn | grep -q 'has address'); then
		warn "$fqdn does not resolve into an IP address";
	fi

	# Not perfect, but better than letters...
	if ! (echo $ip | grep -q '^[0-9]\{1,3\}\(\.[0-9]\{1,3\}\)\{3\}$' ); then
		error 1 "\"$ip\" is not a valid IP address"
	fi

	if ! (echo $arch | grep -q '[a-z].*'); then
		warn "$arch does not appear to be a valid architecture. eg i386"
	fi

	if ! (echo $dist | grep -q '[a-z].*'); then
		warn "$dist does not appear to be a valid Debian distribution. eg woody"
	fi

	if $fakeinit; then
		fakeinit=" fakeinit"
	else
		fakeinit=""
	fi

	if ! (echo $interface | grep -q '[a-z].*'); then
		warn "$interface does not appear to be a valid interface"
		warn "	eg: eth0"
	fi

	if $localapt && [ ! -d /etc/apt ]; then
		error 1 "-l,--localapt is set but /etc/apt does not exist"
	fi

	mirror="${mirror%/}"
	if ! (echo $mirror | egrep -q '(f|ht)tp://[a-z].*[a-z]'); then
		error 1 "$mirror does not appear to be a valid mirror"
	fi

	vsroot="${vsroot%/}"
	if [ ! -d $vsroot ]; then
		error 1 "$vsroot does not exist. vserverutils installed?"
	fi

	if [ $sshkeys != "" -a ! -e $sshkeys ]; then
		error 1 "$sshkeys does not exist"
	fi

	target=$vsroot/$hostname
	if [ -d $target ]; then
		if $force; then
			warn "\"$target\" already exists but proceding anyway"
			vserver $hostname stop

			tmpf=$(tempfile)
			if [ -d $target/var/cache/apt/archives ] && \
			cd $target/.. ; then
				tar cf $tmpf $hostname/var/cache/apt/archives
				rm -rf $target
				tar xf $tmpf
				rm -f $tmpf
			else
				rm -rf $target
			fi
		else
			error 1 "\"$target\" already exists"
		fi
	fi

	targetconf=/etc/vservers/$hostname.conf
	if [ -e $targetconf/etc ]; then
		if $force; then
			warn "\"$targetconf\" exists but proceding anyway"
		else
			error 1 "\"$targetconf\" already exists (-f overrides)"
		fi
	fi
}


### vserver construction/cleanup functions ###

clean_dev () {
	# We *really* don't want to do this to the root server
	if [ "$target" == "/" ]; then
		error 1 "Internal Error: \$target was defined as /!!!!"
	fi

	# Leave only the required devices for correct operation
	info "Cleaning up /dev"
	devices="full null ptmx random tty urandom zero stderr stdin stdout"
	tmpf=$(tempfile)

	if cd $target/dev && tar cfp $tmpf $devices; then
		rm -rf $target/dev/*
		tar xfp $tmpf
		rm -f $tmpf
		mkdir pts
		mkdir shm
	else
		warn "$target/dev does not exist. debootstrap failure?"
	fi
}

clean_inittab () {
	info "Cleaning up /etc/inittab"
	inittab=$target/etc/inittab
	tmpf=$(tempfile)
	if (sed -e 's/.*respawn:\/sbin\/getty.*/#&/' \
	-e 's/.*respawn:\/sbin\/sulogin.*/#&/' $inittab > $tmpf; ); then
		mv $tmpf $inittab
	fi
	rm -f $tmpf
}

clean_rclinks () {
	info "Removing hardware related items from /etc/rc?.d/"
	# We have to remove the links themselves and not the packages because
	# of the deb dependancies
	hw_based="checkfs.sh checkroot.sh console-screen.sh devpts.sh \
	hostname.sh hwclock.sh hwclockfirst.sh ifupdown iptables \
	keymap.sh makedev modutils mountall.sh networking procps \
	setserial umountfs urandom "

	for link in $hw_based
	do
		chroot $target /usr/sbin/update-rc.d -f $link remove
	done
}

create_mtab () {
	info "Creating dummy mtab (for df), fstab and motd"
	# Create a dummy mtab (for the mount/df commands)
cat << EOF > $target/etc/mtab
/dev/hdv1 / vfs rw 0 0
proc /proc proc rw 0 0
none /dev/pts devpts rw,gid=5,mode=620 0 0
EOF

	cat << EOF > $target/etc/fstab
# /etc/fstab: static file system information.
#
# <file system>	<mount point>	<type>	<options>		<dump>	<pass>
proc		/proc		proc	defaults		0	0
EOF

	# Set the motd, and stop it from being edited when
	# /etc/init.d/bootmisc.sh runs
	echo "Debian GNU/Linux ($dist/$(uname -m)) $fqdn" > $target/etc/motd

	rcS=$target/etc/default/rcS
	tmpf=$(tempfile)
        if sed -e 's/^EDITMOTD=yes/EDITMOTD=no/' $rcS > $tmpf ; then
		mv $tmpf $rcS
	fi
	rm -f $tmpf
}

create_crontab () {
	# By default the Debian Install script runs zillions of cron jobs at
	# 0625 every morning.  On a system with lots of vservers all trying to
	# scan the disk at the same time this causes $MAJOR disk-thrash.  So
	# we randomize it a bit so that they run evenly between 1am and 7am,
	# avoiding the 5minutes either side of the hour when other stuff tends
	# to be scheduled.  (BTW, this solution is Overkill!)

	# This looks over complicated--and it probably is...:
	#
	# a) We want the DAILY jobs to run between :05 and :55 minutes past
	# b) We want the WEEKLY job 3-5 minutes after the DAILY.
	# c) And the MONTHLY job 3-5 minutes after that.
	# d) Make sure all three jobs are started by 55minutes past (five-to)
	#    ...if they were ever to all run on the same day!

	d1=$(($RANDOM % 3 + 3));      #   between  3 and  5
	d2=$(($RANDOM % 3 + 3));      #   between  3 and  5
	dt=$((50 - $d1 - $d2));       #   between  0 and 44

	DAILY=$(($RANDOM % $dt + 5))  #   between  5 and 49
	WEEKLY=$(($DAILY + $d1))      #   between  8 and 52
	MONTHLY=$(($WEEKLY + $d2))    #   between 11 and 55

	HOUR=$(($RANDOM % 6 + 1))     #   between  1 and  7 (AM localtime)

	# Create replacement /etc/crontab with randomized times above
	cat << EOF > $target/etc/crontab
# /etc/crontab: system-wide crontab
# Unlike any other crontab you don't have to run the \`crontab'
# command to install the new version when you edit this file.
# This file also has a username field, that none of the other crontabs do.

SHELL=/bin/sh
PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin

# m h dom mon dow user  command
$DAILY $HOUR    * * *   root    test -e /usr/sbin/anacron || run-parts --report /etc/cron.daily
$WEEKLY $HOUR   * * 7   root    test -e /usr/sbin/anacron || run-parts --report /etc/cron.weekly
$MONTHLY $HOUR  1 * *   root    test -e /usr/sbin/anacron || run-parts --report /etc/cron.monthly

EOF
}

configure_networking () {
	info "Configuring networking based on root server"
	# /etc/resolv.conf is created during the debootstrap process so
	# don't do anything for that here.

	# Set up the /etc/hosts file (needed for some parts of the base-config)
	cat << EOF > $target/etc/hosts
# /etc/hosts (automatically generated by vserverutils)

127.0.0.1	localhost
$ip	$fqdn $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
ff02::3 ip6-allhosts
EOF

}

configure_apt () {
	if $localapt; then
		info "Setting up apt based on root server"
		cp -r /etc/apt/*  $target/etc/apt/
	else
		info "Generating default /etc/apt/sources.list"
		cat << EOF > $target/etc/apt/sources.list
deb $mirror/ stable main non-free contrib
deb-src $mirror/ stable main non-free contrib

deb http://non-us.debian.org/debian-non-US stable/non-US main contrib non-free
deb-src http://non-us.debian.org/debian-non-US stable/non-US main contrib non-fr
ee

deb http://security.debian.org stable/updates main contrib non-free

EOF
	fi

}

create_conf () {
	info "Creating config file: /etc/vservers/$hostname.conf"
	# Create default /etc/vservers entry
cat << EOF > /etc/vservers/$hostname.conf
S_HOSTNAME="$hostname"
IPROOT="$ip"
IPROOTDEV="$interface"
ONBOOT="yes"
S_NICE=""
S_FLAGS="lock nproc$fakeinit"
ULIMIT="-H -u 256 -n 1024"
S_CAPS="CAP_NET_RAW"

# This is for NIS, not DNS
S_DOMAINNAME=""

EOF
}

default_packages () {
	info "Setting default package selections"

	tmpf=(tempfile)
	for package in $purge
	do
		echo "$package purge" >> $tmpf
	done
  
	for package in $install
	do
		echo "$package install" >> $tmpf
	done

	cat $tmpf | chroot $target dpkg --set-selections
	rm -f $tmpf

	info "Updating apt databases"
	chroot $target dselect update

	# Download only - leave the configuration for later on
	info "Downloading default packages (this can take some time)"
	chroot $target apt-get --assume-yes --download-only dselect-upgrade
}

copy_sshkeys () {
	if [ -f $sshkeys ]; then
		info "Copying root SSH key to vserver"
		mkdir -p $target/root/.ssh
       		chmod 700 $target/root/.ssh/
		cat $sshkeys >> $target/root/.ssh/authorized_keys
		chmod 600 $target/root/.ssh/authorized_keys
		if [ -f $target/etc/ssh/ssh_host_rsa_key.pub ]; then
			info "Copying host SSH keys for vserver to roothost"
			echo "$hostname,$fqdn,$ip $(cat $target/etc/ssh/ssh_host_rsa_key.pub)" >> /etc/ssh/ssh_known_hosts2
		fi
	fi
}

create_vserver () {
	info "Running debootstrap to install \"$dist\" (takes a while)"
	if ! debootstrap --arch $arch $dist $target $mirror; then
		error 1 "debootstrap failed"
	fi

	clean_dev
	clean_rclinks
	create_mtab
	clean_inittab
	create_crontab
	configure_networking
	configure_apt
	default_packages
	create_conf

	info "Interactive configuration..."
	interactive
	sleep 2


	chroot $target tzsetup -y
	chroot $target dpkg-reconfigure passwd

	# Unfortunately the current packages dependencies don't let
	# you do with exim. ie impossible to run a server without mta
	rm -f $target/etc/exim/exim.conf
	chroot $target eximconfig

	# configure and install default packages downloaded earlier
	# This must be interactive in case debconf asks questions
	chmod 000 $target/..
	vserver $hostname exec apt-get --assume-yes dselect-upgrade

	if ! $verbose; then
		clear
		noninteractive
	fi

	# ssh only just got installed, if at all
	copy_sshkeys

	info "Cleaning up vserver processes"
	export PREVLEVEL=2
	vserver $hostname exec /etc/init.d/rc 0
	vserver $hostname stop

	info "Virtual Server \"$hostname\" successfully installed."
	info "	Make your changes to $targetconf and type"
	info "		vserver $hostname start"
	info "	to start it. debian/rules!"
}


### Default values ###

# Configuration priority is:
# 	Internal defaults
#	/etc/vservers/debvserver (if it exists)
#	Values from --config (fail if it doesn't exist)
#	Command line options

verbose=(false)
conf=/etc/vservers/debvserver
arch="i386"
dist="woody"
force=(false)
fakeinit=(false)
install=""
purge="dhcp-client lilo makedev pcmcia-cs ppp pppconfig pppoe pppoeconf setserial syslinux nano fdutils iptables libpcap0 pciutils"
interface="eth0"
localapt=(false)
mirror="http://http.us.debian.org/debian"
vsroot="/vserver"
sshkeys=""

if [ -e $conf ]; then
	. $conf
fi


### Command line options ###

if [ $# -eq 0 ]; then  # Script invoked with no command-line args?
	usage
	exit 1
fi  

temp=$(getopt -o hVvc:a:d:fi:klm:r:s: --long help,version,verbose,config,arch:,dist:,force,install,purge,interface:,fakeinit,localapt,mirror:,vsroot:,sshkeys: -n $me -- "$@")

if [ $? != 0 ]; then
	echo "	(See -h for help)"
	exit 1
fi

# Note the quotes around `$temp': they are essential!
eval set -- "$temp"

while true; do
	case "$1" in
		-h|--help)	full_usage
				exit 1
				;;
		-V|--version)	full_version
				exit 1
				;;
		-v|--verbose)	verbose=(true)
				shift
				;;
		-c|--config)	conf="$2"
				if [ ! -e $conf ]; then
					error 1 "$conf does not exist"
				fi
				. $conf
				shift 2
				;;
		-a|--arch)	arch="$2"
				shift 2
				;;
		-d|--dist)	dist="$2"
				shift 2
				;;
		-f|--force)	force=(true)
				shift
				;;
		   --install)	install="$2"
		   		shift 2
				;;
		   --purge)	purge="$2"
		   		shift 2
				;;
		-i|--interface)	interface="$2"
				shift 2
				;;
		-k|--fakeinit)	fakeinit=(true)
				shift
				;;
		-l|--localapt)	localapt=(true)
				shift
				;;
		-m|--mirror)	mirror="$2"
				shift 2
				;;
		-r|--vsroot)	vsroot="$2"
				shift 2
				;;
		-s|--sshkeys)	sshkeys="$2"
				shift 2
				;;
		--)		shift
				break
				;;
		*)		echo "Internal error!"
				exit 1
				;;
	esac
done

if [ $# -ne 3 ]; then
	usage
	exit 1
fi

info "Using $conf for defaults"

if $verbose; then
	interactive
else
	noninteractive
fi

check_config $*
create_vserver

exit 0