#!/bin/bash
#
# This is designed to be called from cron

debug() {
    [ $DEBUG -eq 1 ] && echo "DEBUG: $*"
}

complain() {
    if [ $DEBUG -eq 1 ]; then
	echo "ERROR: $*"
    else
	logger -t "athena-auto-upgrade" -p user.notice "$*"
    fi
}

# Redirect output to a log file
exec >>/var/log/athena-upgrade 2>&1
echo "Starting upgrade at $(date)"

DEBUG=0
MAYBE=""
if [ "$1" = "--debug" ]; then
    DEBUG=1
    MAYBE=echo
fi

UPGRADE_TO_TESTING=no
UPGRADE_ANYWAY=no
[ -f /etc/default/debathena-auto-update ] && . /etc/default/debathena-auto-update

if [ $DEBUG -eq 1 ]; then
    UPGRADE_TO_TESTING=yes
    UPGRADE_ANYWAY=yes
fi

# Not supported on Debian
if [ "$(lsb_release -si)" != "Ubuntu" ]; then
    debug "Only supported on Ubuntu.".
    exit 0
fi

# Skip other sanity checks in debug mode
if [ $DEBUG -ne 1 ]; then
    # Only run this on cluster
    if [ "$(machtype -L)" != "debathena-cluster" ] && \
       [ "$UPGRADE_ANYWAY" != "yes" ]; then
	debug "Not a cluster machine and UPGRADE_ANYWAY != yes.".
	exit 0
    fi
    
    # Bail if someone is logged in (stolen from auto-update)
    ttys=$(w -h -s | awk '{print $2}')
    for tty in $ttys; do
	pids=$(ps --no-heading -j -t "$tty" 2>/dev/null \
            | awk '($1 == $3) {print $1}')
	if [ -n "$pids" ]; then
	    debug "Users logged in, won't continue."
	    debug "PIDs: $pids"
            exit 0
	fi
    done
    # screen processes count as logins.
    if pgrep '^screen' > /dev/null; then
	debug "Screen processes found, won't continue."
	exit 0
    fi
fi

CLUSTERINFO=`getcluster -b $(lsb_release -sr)`
[ $? != 0 ] && complain "Failed to get clusterinfo" && exit 1
eval $CLUSTERINFO
if [ ! -z "$NEW_PRODUCTION_RELEASE" ]; then
    debug "Taking new production release: $NEW_PRODUCTION_RELEASE"
    NEWCLUSTER=`getcluster -b $NEW_PRODUCTION_RELEASE`
    [ $? != 0 ] && complain "Failed to get clusterinfo" && exit 1
    eval $NEWCLUSTER
elif [ ! -z "$NEW_TESTING_RELEASE" ] && \
    [ "$UPGRADE_TO_TESTING" = "yes" ]; then
    debug "Taking new testing release: $NEW_TESTING_RELEASE"
    NEWCLUSTER=`getcluster -b $NEW_TESTING_RELEASE`
    [ $? != 0 ] && complain "Failed to get clusterinfo" && exit 1
    eval $NEWCLUSTER
else
    debug "No new releases."
    exit 0
fi
if [ "$(lsb_release -sc)" = "$UBUNTU_RELEASE" ]; then
    complain "Tried to upgrade to already running release; shouldn't happen"
    exit 1
fi
debug "OK, trying to upgrade to $UBUNTU_RELEASE"

# That's a space and then a tab inside the brackets
if egrep -q '^flags[ 	].* lm( |$)' /proc/cpuinfo; then 
    arch=amd64
else 
    arch=i386
fi
debug "Arch: $arch"
IPADDR=`ifconfig eth0 |perl -ne'/^\s+inet addr:([\d\.]+)/ && print $1'`
if [ -z "$IPADDR" ]; then
    complain "Couldn't get IP address from ifconfig!"
    exit 0
fi
debug "Using IPADDR=$IPADDR"
$MAYBE mkdir /h
$MAYBE cd /h
$MAYBE wget -N http://debathena.mit.edu/net-install/${UBUNTU_RELEASE}/${arch}/initrd.gz
$MAYBE wget -N http://debathena.mit.edu/net-install/${UBUNTU_RELEASE}/${arch}/linux
# This is just the guts of the hackboot script:
dkargs="DEBCONF_DEBUG=5"
kargs="netcfg/get_hostname= locale=en_US console-setup/layoutcode=us \
       interface=auto \
       url=http://18.9.60.73/installer/${UBUNTU_RELEASE}/debathena.preseed \
       debathena/clusterforce=yes debathena/clusteraddr=$IPADDR --"
debug "Would execute kexec with --append=\"$dkargs $kargs\""
if [ $DEBUG -eq 1 ]; then
    exit 0
fi
/sbin/kexec -l linux --append="$dkargs $kargs" --initrd=initrd.gz \
    && sleep 3 && chvt 1 && sleep 2 && /sbin/kexec -e
complain "Failed to kexec."
exit 1