Monitoring events and push to Redis

monitor.sh

#!/bin/sh

if [ -z "$(which redis-cli)" ]; then
  apk add --no-cache redis
fi

MONITOR_URL=$1
EVENT_NAME=${EVENT_NAME:=status}
REDIS_HOST=${REDIS_HOST:=localhost}
EVENT_QUEUE=${EVENT_QUEUE:=monitoring:events}
TIMEOUT=${TIMEOUT:=1}
INTERVAL=${INTERVAL:=5}

echo "Monitoring ${MONITOR_URL} for '${EVENT_NAME}' events"

while true; do
	event="$(wget -q -O - -T $TIMEOUT $MONITOR_URL)"
	if [ ! -z "$event" ]; then
		echo "$(date -uIseconds) $event"
		ok=$(timeout -t $TIMEOUT \
			redis-cli -h $REDIS_HOST lpush $EVENT_QUEUE \
			"$EVENT_NAME\0$(hostname)\0$(date +%s)\0${event}")
		if [ -z "$ok" ]; then
			echo "$(date -uIseconds) Failed to queue event"
		fi
	else
		echo "$(date -uIseconds) Failed to fetch event"
	fi
	sleep $INTERVAL
done