#!/bin/bash
# vim: set fileencoding=utf-8 ts=4 sw=4 noexpandtab

PORTICRON_VERSION="0.5"

version() {
	echo "porticron ${PORTICRON_VERSION}"
	echo "Copyright (c) 2008-2009 Benedikt Böhm <bb@xnull.de>"
	exit 0
}

usage() {
	echo "Usage: porticron [-hvn] [-c <file>]"
	echo
	echo "  -h         print this help text"
	echo "  -v         enable verbose output"
	echo "  -V         print version number"
	echo "  -n         do not send upgrade mails"
	echo "  -c <file>  use configuration in <file>"
	echo
	exit 0
}

log() {
	[[ ${VERBOSE} -eq 1 ]] && echo "$@" >&2
}

send_mail() {
	if [[ ${NOMAIL} -eq 1 ]]; then
		cat
	else
		${SENDMAIL:-/usr/sbin/sendmail} -t
	fi
}


# parse command line
while getopts "hvVnc:" opt; do
	case $opt in
		h) usage;;
		v) VERBOSE=1;;
		V) version;;
		n) NOMAIL=1;;
		c) PORTICRON_CONF=${OPTARG};;
		?) exit 1;;
	esac
done


# defaults
: ${VERBOSE:=0}
: ${NOMAIL:=0}
: ${PORTICRON_CONF:=/etc/porticron.conf}
log "using PORTICRON_CONF=${PORTICRON_CONF}, NOMAIL=${NOMAIL}, VERBOSE=${VERBOSE}"


# load config
if [[ ! -r ${PORTICRON_CONF} ]]; then
	echo "could not open configuration file ${PORTICRON_CONF}"
	exit 1
else
	source ${PORTICRON_CONF}
fi


# detect some common variables
SCRIPT_NAME=$(basename $0)
FQDN=$(hostname --fqdn)
IP=$(dig +short ${FQDN} | tr '\n' ' ')
DATE=$(date -R)
PORTDIR=$(portageq portdir)


# sync if desired
log "running SYNC_CMD: ${SYNC_CMD:-/usr/bin/emerge --sync}"
${SYNC_CMD:-/usr/bin/emerge --sync} &>/dev/null
log "running SYNC_OVERLAY_CMD: ${SYNC_OVERLAYS_CMD:-/bin/true}"
${SYNC_OVERLAYS_CMD:-/bin/true} &>/dev/null


# GLSA check
log "running GLSA_AFFECTED: /usr/bin/glsa-check --test --verbose affected"
GLSA_AFFECTED=$(/usr/bin/glsa-check --test --verbose affected 2>/dev/null)
log "running GLSA_UPGRADES: /usr/bin/glsa-check --pretend affected"
GLSA_UPGRADES=$(/usr/bin/glsa-check --pretend affected | grep '^     ')

if [[ -n ${GLSA_AFFECTED} ]]; then
	GLSA_MSG="
${SCRIPT_NAME} has detected that this system is affected by the following GLSAs:

$(echo "${GLSA_AFFECTED}" | sed 's/^20/     20/')

========================================================================

The following updates should be performed for these GLSAs:

${GLSA_UPGRADES}
"

	cat <<EOF | send_mail
To: ${RCPT:-root@${FQDN}}
From: root@${FQDN}
Subject: WARNING: Gentoo security updates on ${FQDN} [ ${IP} ]
Date: ${DATE}

porticron report [${DATE}]
========================================================================
${GLSA_MSG}
--
${SCRIPT_NAME}
EOF
fi


# build a list of changed ebuilds
if [[ -n ${DIFF_CMD} ]]; then
	log "running DIFF_CMD: ${DIFF_CMD}"
	DIFF=$(${DIFF_CMD} 2>/dev/null)
fi

if [[ -n ${DIFF} ]]; then
	DIFF_MSG="${SCRIPT_NAME} has detected the following changes to ${PORTDIR}:

${DIFF}

========================================================================
"
fi


# build list of upgrades
: ${UPGRADE_OPTS:=--deep --update}
log "running UPGRADE_CMD: /usr/bin/emerge ${UPGRADE_OPTS} --quiet --pretend world"
UPGRADE=$(/usr/bin/emerge ${UPGRADE_OPTS} --quiet --pretend world 2>/dev/null)

if [[ -n ${UPGRADE} ]]; then
	UPGRADE_MSG="
${SCRIPT_NAME} has detected that some packages need upgrading:

$(echo "${UPGRADE}" | sed 's/^\[/    [/')

========================================================================

You can perform the upgrade by issuing the command:

    emerge ${UPGRADE_OPTS} world

as root on ${FQDN}

It is recommended that you pretend the upgrade first to confirm that
the actions that would be taken are reasonable. The upgrade may be
pretended by issuing the command:

    emerge ${UPGRADE_OPTS} --pretend world

"
fi


# send mail
if [[ -z ${UPGRADE_MSG} && -z ${DIFF_MSG} ]]; then
	log "no upgrades found, exiting."
	exit 0
fi

cat <<EOF | send_mail
To: ${RCPT:-root@${FQDN}}
From: root@${FQDN}
Subject: Gentoo package updates on ${FQDN} [ ${IP} ]
Date: ${DATE}

porticron report [${DATE}]
========================================================================
${DIFF_MSG}${UPGRADE_MSG}
--
${SCRIPT_NAME}
EOF