check_redis

#!/bin/bash

. $(dirname $0)/lib.sh

# Quick function to calculate and format rates from counters.
function per_second() {
	eval PREV=\$PREV_$1
	eval CUR=\$CUR_$1
	bc -l <<< "r=($CUR-${PREV:-0})/$SECONDS;scale=23-length(r);r/1" 2>/dev/null
}

# Defaults
HOST="localhost"
PORT="6379"
DB="0"

while getopts "h:p:s:a:" OPT; do
	case $OPT in
		h) HOST=$OPTARG ;;
		p) PORT=$OPTARG ;;
		s) SOCKET=$OPTARG ;;
		a) PASSWORD=$OPTARG ;;
		n) DB=$OPTARG ;;
	esac
done

# If a socket is provided it overrides the host and port options.
if [[ $SOCKET ]]; then
	OPTS="-s $SOCKET"
	PREV_STATE=/var/lib/nagioschecks/check_redis_${SOCKET//\//}_$DB
else
	OPTS="-h $HOST -p $PORT"
	PREV_STATE=/var/lib/nagioschecks/check_redis_${HOST}_${PORT}_$DB
fi

if [[ $PASSWORD ]]; then
	OPTS="$OPTS -a $PASSWORD"
fi

# This doesn't really have any effect, because we just run the info command.
if [[ $DB ]]; then
	OPTS="$OPTS -n $DB"
fi

# redis-cli just prints a message on stderr if the connection fails.
INFO=$(redis-cli $OPTS info 2>/dev/null)

# So when nothing was captured from stdout, it's bad.
if [[ -z $INFO ]]; then
	echo "CRITICAL - Failed to connect to Redis"
	exit $STATE_CRITICAL
fi

# Try to load the previously saved state.
if [ -f $PREV_STATE ]; then
	PREV_MTIME=$(stat -c %Y $PREV_STATE)
	. $PREV_STATE
fi

# Determine the current state, save it for the next run, and load it.
STATE=$(sed -nr 's/\r//;/^db/!s/^([^:]*):(.*)$/\U\1\E="\2"/p;/^db'$DB\
'/{s/[^:]*:([^,]*),([^,]*).*/\U\1\n\2/p}' <<< "$INFO")
sed 's/^/PREV_/' <<< "$STATE" > $PREV_STATE
eval $(sed 's/^/CUR_/' <<< "$STATE")

# In case of a first run or a restart, average over the uptime.
if [[ $PREV_UPTIME_IN_SECONDS &&
		$PREV_UPTIME_IN_SECONDS -lt $CUR_UPTIME_IN_SECONDS ]]; then
	SECONDS=$(($(date +%s) - PREV_MTIME))
else
	SECONDS=$CUR_UPTIME_IN_SECONDS
	# Forget all the values from before the restart.
	eval unset $(set | sed -n /^\\\(PREV_[^=]*\\\).*/s//\\1/p)
fi

COMMANDS_S=$(per_second TOTAL_COMMANDS_PROCESSED)
HITS_S=$(per_second KEYSPACE_HITS)
MISSES_S=$(per_second KEYSPACE_MISSES)
EXPIRED_S=$(per_second EXPIRED_KEYS)
EVICTED_S=$(per_second EVICTED_KEYS)

echo "OK - \
$COMMANDS_S commands/s, $HITS_S hits/s, $MISSES_S misses/s, \
$EXPIRED_S expired/s, $EVICTED_S evicted/s - \
$CUR_KEYS keys, $CUR_EXPIRES expires - \
$(bytes_to_human_bi $CUR_USED_MEMORY) used, \
$(bytes_to_human_bi $CUR_USED_MEMORY_PEAK) peak|\
commands=$COMMANDS_S hits=$HITS_S misses=$MISSES_S \
expired=$EXPIRED_S evicted=$EVICTED_S \
keys=$CUR_KEYS expires=$CUR_EXPIRES \
memory=${CUR_USED_MEMORY}B memoryRss=${CUR_USED_MEMORY_RSS}B \
aof=${CUR_AOF_CURRENT_SIZE}B"

exit $STATE_OK