Command:
certbot certonly --manual --preferred-challenges=dns --manual-auth-hook ./authenticator.sh --manual-cleanup-hook ./cleanup.sh --deploy-hook ./deploy.sh -d *.example.com -d example.com
Check Certificate’s Expiration Date:
echo | openssl s_client -connect example.com:443 -servername example.com 2>/dev/null | openssl x509 -noout -dates
Cron:
10 0 * * * certbot renew