Renew a Let's Encrypt cert within a week of expiration. Run weekly. Or Daily.

le-cert-renew.fish

#!/bin/fish

# Get dates in seconds since epoch
set -x EXPIRES (date --date=(cat /etc/letsencrypt/live/api.fyrestead.com/cert.pem  | openssl x509 -noout -enddate | awk -F "=" '{print $2}') +%s)
set -x TODAY (date +%s)
set -x SPAN (expr $EXPIRES - $TODAY)

# if the span is <= seven days ...
if test $SPAN -le 604800
	# renew the cert
	certbot renew --quiet
end