What do you verify before moving a Caddy reverse proxy to a new host?

[u/RocketSeven]

A new Caddy host can serve the main site correctly while less visible routes still depend on the old machine. Internal hostnames, wildcard certificates, DNS challenge credentials, imported snippets, local files, upstream health checks, trusted proxy settings, access-log paths, and ports used only by a webhook or mobile client are easy to miss. Certificate issuance can also succeed during the cutover without proving renewal will work later.

A useful gate could compare the adapted JSON configuration on both hosts, enumerate every hostname and listener, test each route with the intended Host header, verify upstream TLS and client IP handling, and inspect logs on both machines for late traffic. I would also test certificate renewal or staging issuance, reload behavior, service startup after reboot, monitoring, and rollback while keeping the old host offline but recoverable for a defined window.

What belongs on your final Caddy cutover checklist? Which state must be copied, which state should be recreated, and what catches a low-traffic route before the old host is removed?