crontab header

# @author Cleybert Andre
#
# cron.d/dns-fix -- Search for the fastest DNS resolver every 5 minutes.
#                   Available environment variables are documented on the script.
#
# ┌──────── minute (0 - 59 or "*/X" for every X minutes)
# │   ┌─────── hour (0 - 23)
# │   │   ┌────── day of month (1 - 31)
# │   │   │   ┌────── month (1 - 12)
# │   │   │   │   ┌───── day of week (0 - 6 => Sunday - Saturday, or 1 - 7 => Monday - Sunday)
# │   │   │   │   │   ┌───── run as this user
# │   │   │   │   │   │    ┌── command to run (use: >/dev/null 2>&1 to ignore errors)
# ↓   ↓   ↓   ↓   ↓   ↓    ↓
 */5  *   *   *   *   root  NS_1=8.8.8.8 NS_2=1.1.1.1 NS_3=208.67.222.222 -E /etc/rotinas/dns-healthy.sh