Add Nagios check to gather statistics about archived mails

contrib/nagios/README.md

@@ -0,0 +1,33 @@
+## Setup
+
+- Needs a user with read privileges
+
+```
+GRANT SELECT ON piler.metadata TO 'piler_ro'@'localhost';
+```
+
+- Example
+
+```
+./check_piler_mailrate.sh -h localhost -u piler_ro -p yourpassword -w 10:200 -c 5:500 -t 1:h --no-ssl
+```
+
+- Command definition for Nagios
+
+```
+define command {
+	command_name	check_mailpiler
+	command_line	/usr/local/nagios/libexec/check_mailpiler.sh -h $HOSTADDRESS$ -u $ARG1$ -p $ARG2$ -w $ARG3$ -c $ARG4$ -t $ARG5$ --no-ssl
+}
+```
+
+- Service definition
+
+```
+define service {
+	use						generic-service
+	host_name				piler.example.com
+	service_description		MailPiler - Incoming mails
+	check_command			check_mailpiler!sqluser!sqlpass!10:200!5:500!1:h
+}
+```

contrib/nagios/check_mailpiler.sh

@@ -0,0 +1,251 @@
+#!/bin/bash
+
+# =========================
+# Defaults
+# =========================
+MYSQL_HOST="localhost"
+MYSQL_USER=""
+MYSQL_PASS=""
+MYSQL_DB="piler"
+
+MYSQL_SSL_OPTION="--ssl" # default: SSL enabled
+
+WARN_RANGE=""
+CRIT_RANGE=""
+
+TIME_VALUE=1
+TIME_UNIT="m" # default: minutes
+
+# =========================
+# Error helper
+# =========================
+die() {
+	echo "UNKNOWN - $1"
+	exit 3
+}
+
+# =========================
+# Usage
+# =========================
+usage() {
+	echo "Usage:"
+	echo "  $0 -u USER -p PASS [OPTIONS]"
+	echo
+	echo "Required:"
+	echo "  -u, --user           MySQL user (read-only)"
+	echo "  -p, --password       MySQL password"
+	echo
+	echo "Optional:"
+	echo "  -h, --host           MySQL host (default: localhost)"
+	echo "  -w, --warning        Warning range (Nagios range syntax)"
+	echo "  -c, --critical       Critical range (Nagios range syntax)"
+	echo "  -t, --timewindow     Time window VALUE[:UNIT]"
+	echo "                       UNIT = m (minutes), h (hours), d (days)"
+	echo "                       Default: 1:m"
+	echo "      --no-ssl         Disable SSL for MySQL connection"
+	echo "      --help           Show this help"
+	exit 3
+}
+
+# =========================
+# Range Parser (for Sanity Check)
+# =========================
+parse_range() {
+	local range="$1"
+	local start=0
+	local end="999999999"
+
+	[[ "$range" =~ ^@ ]] && range="${range#@}"
+
+	if [[ "$range" == *:* ]]; then
+		start="${range%%:*}"
+		end="${range##*:}"
+	else
+		start="0"
+		end="$range"
+	fi
+
+	[[ -z "$start" || "$start" == "~" ]] && start="-999999999"
+	[[ -z "$end" ]] && end="999999999"
+
+	echo "$start $end"
+}
+
+# =========================
+# Nagios range check
+# returns 0 = OK, 1 = ALERT
+# Sets RANGE_SIDE to "low" or "high"
+# =========================
+check_range() {
+	local value="$1"
+	local range="$2"
+	RANGE_SIDE=""
+
+	[[ -z "$range" || "$range" == "0" ]] && return 0
+
+	local invert=0
+	local start=""
+	local end=""
+
+	[[ "$range" =~ ^@ ]] && invert=1 && range="${range#@}"
+
+	if [[ "$range" == *:* ]]; then
+		start="${range%%:*}"
+		end="${range##*:}"
+	else
+		start="0"
+		end="$range"
+	fi
+
+	[[ -z "$start" ]] && start="0"
+	[[ "$start" == "~" ]] && start="-inf"
+	[[ -z "$end" ]] && end="+inf"
+
+	local in_range=1
+
+	if [[ "$start" != "-inf" ]] && (( $(awk "BEGIN{print ($value < $start)}") )); then
+		in_range=0
+		RANGE_SIDE="low"
+	fi
+
+	if [[ "$end" != "+inf" ]] && (( $(awk "BEGIN{print ($value > $end)}") )); then
+		in_range=0
+		RANGE_SIDE="high"
+	fi
+
+	if [[ $invert -eq 1 ]]; then
+		if [[ $in_range -eq 1 ]]; then
+			RANGE_SIDE="inside_range"
+			return 1
+		else
+			return 0
+		fi
+	else
+		[[ $in_range -eq 1 ]] && return 0 || return 1
+	fi
+}
+
+# =========================
+# getopt parsing
+# =========================
+PARSED=$(getopt \
+-o h:u:p:w:c:t: \
+--long host:,user:,password:,warning:,critical:,timewindow:,no-ssl,help \
+-- "$@")
+
+[[ $? -ne 0 ]] && die "invalid command line arguments"
+
+eval set -- "$PARSED"
+
+while true; do
+	case "$1" in
+		-h|--host)
+			MYSQL_HOST="$2"; shift 2;;
+		-u|--user)
+			MYSQL_USER="$2"; shift 2;;
+		-p|--password)
+			MYSQL_PASS="$2"; shift 2;;
+		-w|--warning)
+			WARN_RANGE="$2"; shift 2;;
+		-c|--critical)
+			CRIT_RANGE="$2"; shift 2;;
+		-t|--timewindow)
+			IFS=: read TIME_VALUE TIME_UNIT <<< "$2"
+			[[ -z "$TIME_UNIT" ]] && TIME_UNIT="m"
+			shift 2;;
+		--no-ssl)
+			MYSQL_SSL_OPTION="--skip-ssl"; shift;;
+		--help)
+			usage;;
+		--)
+			shift; break;;
+		*)
+			die "internal getopt error";;
+	esac
+done
+
+# =========================
+# Validation
+# =========================
+[[ -z "$MYSQL_USER" ]] && die "MySQL user missing"
+[[ -z "$MYSQL_PASS" ]] && die "MySQL password missing"
+[[ ! "$TIME_VALUE" =~ ^[0-9]+$ ]] && die "time value must be numeric"
+[[ "$TIME_VALUE" -le 0 ]] && die "time window value must be greater than 0"
+
+# Sanity Check for Ranges
+if [[ -n "$WARN_RANGE" && -n "$CRIT_RANGE" ]]; then
+	read w_start w_end < <(parse_range "$WARN_RANGE")
+	read c_start c_end < <(parse_range "$CRIT_RANGE")
+
+	if (( $(awk "BEGIN{print ($c_end < $w_end)}") )); then
+		die "Configuration error: Critical high limit ($c_end) cannot be lower than Warning high limit ($w_end)"
+	fi
+
+	if (( $(awk "BEGIN{print ($c_start > $w_start)}") )); then
+		die "Configuration error: Critical low limit ($c_start) cannot be higher than Warning low limit ($w_start)"
+	fi
+fi
+
+case "$TIME_UNIT" in
+	m)
+		SQL_INTERVAL="MINUTE"
+		TOTAL_MINUTES=$TIME_VALUE
+		;;
+	h)
+		SQL_INTERVAL="HOUR"
+		TOTAL_MINUTES=$(( TIME_VALUE * 60 ))
+		;;
+	d)
+		SQL_INTERVAL="DAY"
+		TOTAL_MINUTES=$(( TIME_VALUE * 1440 ))
+		;;
+	*)
+		die "invalid time unit '$TIME_UNIT' (use m|h|d)"
+		;;
+esac
+
+# =========================
+# SQL Query
+# =========================
+SQL="SELECT COUNT(*) FROM metadata WHERE arrived > UNIX_TIMESTAMP(NOW() - INTERVAL $TIME_VALUE $SQL_INTERVAL);"
+SQL_OUTPUT=$(mysql -N -s $MYSQL_SSL_OPTION -h "$MYSQL_HOST" -u "$MYSQL_USER" -p"$MYSQL_PASS" "$MYSQL_DB" -e "$SQL" 2>&1)
+
+[[ $? -ne 0 ]] && die "database query failed on host=$MYSQL_HOST: $SQL_OUTPUT"
+
+COUNT="$SQL_OUTPUT"
+[[ ! "$COUNT" =~ ^[0-9]+$ ]] && die "unexpected query result: '$COUNT'"
+
+# =========================
+# Calculate mails/min
+# =========================
+MAILS_PER_MIN=$(awk -v c="$COUNT" -v m="$TOTAL_MINUTES" 'BEGIN { if (m>0) printf "%.2f", c/m; else print "0.00" }')
+
+# =========================
+# Status evaluation
+# =========================
+STATUS="OK"
+EXITCODE=0
+REASON=""
+
+check_range "$COUNT" "$CRIT_RANGE"
+if [[ $? -ne 0 ]]; then
+	STATUS="CRITICAL"
+	EXITCODE=2
+	[[ "$RANGE_SIDE" == "low" ]] && REASON=" (too few mails)"
+	[[ "$RANGE_SIDE" == "high" ]] && REASON=" (too many mails)"
+else
+	check_range "$COUNT" "$WARN_RANGE"
+	if [[ $? -ne 0 ]]; then
+		STATUS="WARNING"
+		EXITCODE=1
+		[[ "$RANGE_SIDE" == "low" ]] && REASON=" (too few mails)"
+		[[ "$RANGE_SIDE" == "high" ]] && REASON=" (too many mails)"
+	fi
+fi
+
+# =========================
+# Output + Perfdata
+# =========================
+echo "$STATUS - $COUNT mails in last ${TIME_VALUE}${TIME_UNIT} (${MAILS_PER_MIN} mails/min)${REASON} | mails_per_min=${MAILS_PER_MIN};;;0; mail_count=${COUNT};${WARN_RANGE};${CRIT_RANGE};0;"
+
+exit $EXITCODE