#!/bin/bash

journal="$(journalctl --since '12 hours ago' --no-hostname _TRANSPORT=kernel | grep -iF 'out of memory' -C1)"

if [[ -n "$journal" ]]
then
    echo "CRITICAL - OOM killer killed processes:"
    echo
    echo "$journal"
    exit 2
else
    echo "OK - No OOM kills found in last 12 hours"
    exit 0
fi