Sudden failure in TLS certificate renewal

[hunghvu]

Out of nowhere, the site is down because TLS certificate cannot be renewed. From research, it appears something is wrong with the DNS of EC2 instance (or a hidden outage, not found any report online?). In any case, using a third-party DNS will solve this.

Helpful resources:

• https://caddy.community/t/could-not-determine-zone-for-domain/18720
• https://caddy.community/t/forcing-certmagic-to-use-system-resolvers-for-propagation-checks/15690/3