Send email when server is running out of memory

Sometimes we have a server with low resources, so we need a way to get an alert when this is becoming critical. For example, we can send us an email when the server is running out of memory.

I found a script made by Aaron Kili Kisinga that does exactly that, so I made some changes to use mpack instead of mailx. Here’s the result:

#!/bin/bash 
#######################################################################################
#Script Name    :lowmemoryalert.sh
#Description    :send alert mail when server memory is running low
#Args           :       
#Author         :Santiago Valdez based on Aaron Kili Kisinga script
#Email          :[email protected]
#License       : GNU GPL-3      
#######################################################################################
## declare mail variables
##email subject 
subject="WARNING! Server is running out of memory"
##sending mail as
#from="[email protected]"
## sending mail to
to="[email protected]"
## send carbon copy to
also_to="[email protected]"

## get total free memory size in megabytes(MB) 
free=$(free -mt | grep Mem | awk '{print $4}')

#echo -e "LIBRE $free \n"

## check if free memory is less or equals to  250MB
if [[ "$free" -le 250  ]]; then
        ## get top processes consuming system memory and save to temporary file 
        ps -eo pid,ppid,cmd,%mem,%cpu --sort=-%mem | head >/tmp/top_proccesses_consuming_memory.txt

        file=/tmp/top_proccesses_consuming_memory.txt
        ## send email if system memory is running low
        echo -e "Atention!, the server is running out of memory!\n\nFree Memory: $free MB\n\n\nThe list of the processes with most memory consumption is attached.\n\n" > /tmp/bodyemail.txt
        body=/tmp/bodyemail.txt
        
        mpack -d "$body" -s "$subject" "$file" "$to" "$also_to"
fi

exit 0