#!/bin/sh

# Munin plugin for monitoring Dovecot logins and IMAP throughput.
# 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

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

. $MUNIN_LIBDIR/plugins/plugin.sh
is_multigraph

case "${1:-}" in
    config) cat <<- EOF
		multigraph dovecot_login_status
		graph_title Dovecot login status
		graph_vlabel logins per \${graph_period}
		graph_args --base 1000 -l 0
		graph_scale no
		graph_period minute
		graph_category dovecot
		successful.label auth successful
		successful.type DERIVE
		successful.draw AREA
		successful.min 0
		failed.label auth failed
		failed.type DERIVE
		failed.draw STACK
		failed.min 0
		noauth.label no auth attempt
		noauth.type DERIVE
		noauth.draw STACK
		noauth.min 0

		multigraph dovecot_login_types
		graph_title Dovecot login types
		graph_vlabel logins per \${graph_period}
		graph_args --base 1000 -l 0
		graph_scale no
		graph_period minute
		graph_category dovecot
		imap.label IMAP
		imap.type DERIVE
		imap.draw AREA
		imap.min 0
		pop3.label POP3
		pop3.type DERIVE
		pop3.draw STACK
		pop3.min 0
		managesieve.label managesieve
		managesieve.type DERIVE
		managesieve.draw STACK
		managesieve.min 0

		multigraph dovecot_imap_throughput
		graph_title Dovecot IMAP throughput
		graph_vlabel bytes per \${graph_period}
		graph_args --base 1024 -l 0
		graph_scale yes
		graph_period minute
		graph_category dovecot
		read.label read
		read.type DERIVE
		read.min 0
		written.label written
		written.type DERIVE
		written.min 0
	EOF
    exit 0
    ;;
esac

if [ ! -f "$LOGFILE" ]; then
    for field in successful failed noauth imap pop3 managesieve read written; do
        echo $field.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:]-]+ dovecot: ##p" >"$tmpfile"

sum() {
    awk 'BEGIN{x=0} {x+=$0} END{print x}'
}

prefix="^(pop3|imap|managesieve)-login"
echo multigraph dovecot_login_status
echo successful.value $(grep -Ec "$prefix: Login: user=<[^>]+>,\s" "$tmpfile")
echo failed.value    $(sed -nr "s#$prefix: Aborted login \(auth failed, ([[:digit:]]+) attempts in [[:digit:]]+ secs\): user=<[^>]*>, .*#\2#p" "$tmpfile" | sum)
echo noauth.value    $(grep -Ec "$prefix: Aborted login \(no auth attempts in [[:digit:]]+ secs\): user=<>,\s" "$tmpfile")


echo multigraph dovecot_login_types
for type in imap pop3 managesieve; do
    echo $type.value $(grep -Ec "^$type-login:\s" "$tmpfile")
done


regexp="^imap\([-_.@[:alnum:]]+\): .* in=([[:digit:]]+) out=([[:digit:]]+)$"
echo multigraph dovecot_imap_throughput
echo read.value    $(sed -nr "s#$regexp#\1#p" "$tmpfile" | sum)
echo written.value $(sed -nr "s#$regexp#\2#p" "$tmpfile" | sum)