#!/bin/sh

# Munin plugin for monitoring Postfix SASL logins.  Symlink/rename to
# 'postfix_sasl_$SYSLOGNAME'.
# Copyright © 2015 Guilhem Moulin <guilhem@fripost.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 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

PATH=/usr/bin:/bin:/usr/sbin:/sbin
set -u

LOGFILE="/var/log/${logfile:-mail.log}"
STATEFILE="$MUNIN_PLUGSTATE/${0##*/}.offset"

name="${0##*/}"
[ "${name#postfix_sasl_}" != "$name" ] && postfix="${name#postfix_sasl_}" || postfix=

case "${1:-}" in
    config) cat <<- EOF
		graph_title Postfix SASL ($([ -n "$postfix" -a "$postfix" != postfix ] && echo "'${postfix#postfix-}'" || echo default) instance)
		graph_vlabel logins per \${graph_period}
		graph_args --base 1000 -l 0
		graph_scale no
		graph_period minute
		graph_category postfix
		successful.label successful
		successful.type DERIVE
		successful.draw AREA
		successful.min 0
		failed.label failed
		failed.type DERIVE
		failed.draw STACK
		failed.min 0
	EOF
    exit 0
    ;;
esac

if [ ! -f "$LOGFILE" ]; then
    for postfix in ${postmulti:-postfix}; do
        echo "${postfix}_volume.value U"
    done
    exit 0;
fi

tmpfile="$(mktemp --tmpdir)"
trap 'rm -f "$tmpfile"' EXIT

logtail -f"$LOGFILE" -o"$STATEFILE" | sed -nr "s#^\w{3} [ :[:digit:]]{11} [._[:alnum:]-]+ $postfix/smtpd\[[[:digit:]]+\]: ##p" >"$tmpfile"

echo successful.value $(grep -Ec "^warning: [-._[:alnum:]]+\[[.[:digit:]]+\]: SASL \S+ authentication failed(:.*)?$" "$tmpfile")
echo failed.value     $(grep -Ec "^[[:xdigit:]]{10}: client=\S+, sasl_method=\S+, sasl_username=" "$tmpfile")