列出所有憑證
#certbot certificates
測試更新
#service apache24 stop
#certbot renew --dry-run
如果出現錯誤「Problem binding to port 80: Could not bind to IPv4 or IPv6」，要事先關閉apache
更新憑證
#service apache24 stop
#certbot renew
#service apache24 start
如果出現錯誤「Timeout during connect (likely firewall problem)」，多執行「#certbot renew --dry-run 」幾次應該會成功，成功後再執行「#certbot renew」