🔗 Caching get_certificate lookups in Caddy

Caddy can serve on-demand ACME certificates automatically, but what happens when customers want to provide their own? In this insightful piece by Mattias Geniar, the focus is on an essential enhancement for Caddy: caching get_certificate lookups. This modification addresses a critical issue where each HTTPS handshake previously triggered a fresh fetch from the backend, resulting in unnecessary overhead.

Geniar introduces a custom Caddy module named caddy-get-certificate-cache, designed to cache certificates efficiently. The module replaces the stock HTTP getter, allowing Caddy to pull from its cache instead of querying the backend on every handshake. By honoring the Cache-Control header and providing options for time-to-live (TTL), it effectively reduces network calls and speeds up certificate retrieval. This solution is poised to optimize performance and enhance the overall user experience before the new feature enters production.