Webmin, Linode, Letsencrypt, Cloudflare, Godaddy

{ crontab -l; echo "@daily /usr/bin/certbot renew >> /var/log/le-renew.log"; } | crontab -
{ crontab -l; echo "0 1   * * * yum -y update"; } | crontab -
{ crontab -l; echo "0 2   * * * /sbin/shutdown -r +5"; } | crontab -
sudo crontab -e
chattr -i /etc/crontab
lsattr /etc/crontab -l

CRON JOBS
sudo crontab -e

# For more information see the manual pages of crontab(5) and cron(8)
#
# m h  dom mon dow   command
@daily /etc/webmin/mysql/backup.pl --all
@daily /usr/bin/certbot renew >> /var/log/le-renew.log
@daily /etc/webmin/postgresql/backup.pl --all
0 */5 * * * /home/rhoportal/others/shell/cloud_backup_script.sh
0 1   * * * yum -y update
0 2   * * * /sbin/shutdown -r +5

service crond restart
tail -f /var/log/cron
grep "cloud_backup_script.sh" /var/log/cron
grep "cert" /var/log/cron
grep "reload_iptables.sh" /var/log/cron