check_alerts_logstash.sh

#!/usr/bin/env bash

[ -s /tmp/logstash_alert ] || exit 1

_mail()
{   #send mail, return 0 on success, 1 otherwise
    #requires: libio-socket-ssl-perl, libnet-ssleay-perl and sendemail
    case $1 in
        gmail)
            shift 
            sendemail -f "$1" -t "$2" -u "$3" -m "$4" -s smtp.gmail.com:587 -o tls=yes -xu "$5" -xp "$6"
            ;;
        *)
            sendemail -f "$1" -t "$2" -u "$3" -m "$4" -s "$5" -xu "$6" -xp "$7" > /dev/null 2>&1
            ;;
    esac

    [ $? -eq 0 ] && return 0 || return 1
}

_mail gmail "noreply@domain.com" "recipient@domain.com" "alarm :$(date +%d-%m-%Y)" "$(cat /tmp/logstash_alert)" "username" "password"

status=$?
[ $status != 0 ] && exit $status || { cat /dev/null > /tmp/logstash_alert; }