Monitor Dovecot with Munin on OpenBSD

  2011-07-24      244 words, 2 minutes

• dovecot
• imap
• monitoring
• munin
• openbsd
• rrdtool

At the time of writing, Munin on OpenBSD doesn’t come with a dovecot dedicated plugin. I’m not sure it even comes with an IMAP plugin. Anyway, you can get one from the “Munin plugin repository” and run it on your BSD box.

Here’s how:

• Grab the dovecot1.2.6 plugin ;
  • Install it ; I dropped it in /etc/munin/plugins/ ;
  • Apply some minor modification to fit OpenBSD:

# diff -U 2 dovecot.orig dovecot
--- dovecot.orig  Sun Jul 24 11:06:17 2011
+++ dovecot     Sun Jul 24 11:28:14 2011
@@ -31,5 +31,5 @@
 # Configuration
 ######################
-STAT_FILE=/var/lib/munin/plugin-state/plugin-dovecot.state
+STAT_FILE=${statefile:-/var/lib/munin/plugin-state/plugin-dovecot.state}
 EXPR_BIN=/usr/bin/expr
 LOGFILE=${logfile:-/var/log/dovecot-info.log}
@@ -46,5 +46,5 @@
        echo 'graph_vlabel Contadores de Login'
        echo 'graph_total total'
-       echo 'graph_category Correo'
+       echo 'graph_category Dovecot'

        echo 'login_total.label Total Logins'
@@ -78,5 +78,5 @@
 ######################

-NEW_TOTAL=$(egrep '*Login' $LOGFILE | grep "`date '+%Y-%m-%d'`" | sort | wc -l)
+NEW_TOTAL=$(egrep '*Login' $LOGFILE | grep "`date '+%Y-%m-%d'`" | sort | wc -l)
 OLD_TOTAL=$(grep TOTAL $STAT_FILE | cut -f2 -d '=')
 TOTAL=$(($NEW_TOTAL - $OLD_TOTAL))
@@ -89,5 +89,5 @@
 # Connected Users
 ######################
-DISCONNECTS=$(egrep '*Disconnected' $LOGFILE | sort | wc -l)
+DISCONNECTS=$(egrep '*Disconnected' $LOGFILE | sort | wc -l)
 CONNECTS=$(egrep '.*Login' $LOGFILE | sort | wc -l)
 DISCON=$(($CONNECTS - $DISCONNECTS))

• Configure Munin:

# vi /etc/munin/plugin-conf.d/openbsd-packages
(...)
[dovecot]
env.logfile /var/log/maillog
env.statefile /var/run/munin/plugin-dovecot.state
(...)

• Restart munin-node and wait 5 minutes

Tada!

Note that I also configured newsyslog to give permissions to munin on maillog:

# vi /etc/newsyslog.conf
(...)
/var/log/maillog        root:_munin     640  7     *    24    Z
(...)

That’s All Folks!
Happy graphing!