Credit: https://blog.d-l.io/auto-renew-letsencrypt

all.start

#!/bin/bash
screen -wipe
cd /root
screen -h 9999 -dmS "ssl-renew"; sleep 0.1
screen -S "ssl-renew" -p 0 -X stuff $"./ssl-renew.sh\n"

certbot

certbot certonly --standalone -d dukelec.com -d www.dukelec.com -d d-l.io -d www.d-l.io -d blog.dukelec.com -d blog.d-l.io -d e.d-l.io

ssl-renew.sh

#!/bin/bash
#
# Software License Agreement (MIT License)
#
# Author: Duke Fong <d(at)d-l.io>
#
# Create ssl-renew.last template:
#   echo "$(date +'%Y-%m-%d %H:%M')" > ssl-renew.last
#
set -e

PROGRESS_BAR_WIDTH=50

draw_progress_bar() {
  # arguments: current value, max value, unit (optional)
  local __value=$1
  local __max=$2
  local __unit=${3:-""}

  if (( $__max < 1 )); then __max=1; fi
  local __percentage=$(( 100 - ($__max*100 - $__value*100) / $__max ))
  local __num_bar=$(( $__percentage * $PROGRESS_BAR_WIDTH / 100 ))

  printf "["
  for b in $(seq 1 $__num_bar); do printf "#"; done
  for s in $(seq 1 $(( $PROGRESS_BAR_WIDTH - $__num_bar ))); do printf " "; done
  printf "] $__percentage%% ($__value / $__max $__unit)\r"
}


renew=$((60*60*24*80)) # renew after 80 day

last=$(tail -n 1 ssl-renew.last)
last=$(date -d "$last" +%s)

next=$((last+renew))

echo "last renew at: $last | $(date --date @$last +'%Y-%m-%d %H:%M')"
echo "next renew at: $next | $(date --date @$next +'%Y-%m-%d %H:%M')"
printf "\n"

while true; do

    cur=$(date +%s)
    offset=$((cur-last))

    draw_progress_bar $offset $renew s

    if (( cur > next )); then
        printf "\n" # end progress bar

        last=$(date +%s)
        next=$((last+renew))

        echo "renew @ $last | $(date --date @$last +'%Y-%m-%d %H:%M') ..."
        echo "$(date --date @$last +'%Y-%m-%d %H:%M')" >> ssl-renew.last

        echo "stop apache..."
        /etc/init.d/apache2 stop

        echo "certbot renew..."
        certbot renew -n

        echo "start apache..."
        /etc/init.d/apache2 start
        sync
        echo "done, next renew at: $next | $(date --date @$next +'%Y-%m-%d %H:%M')"
        printf "\n"
    fi

    sleep 5
done