ACME Server implementation (http-01 challenge). Builtin CA to sign/revoke certificates (can be replaced with an external CA), CA rollover is supported. Notification Mails (account created, certificate will expire soon, certificate is expired) with customizable templates. Web UI (certificate log) with customizable templates.
Tested with Certbot, Traefik, Caddy, uacme, and acme.sh.
The Dockerfile is remarkably understandable, which should make it easy to run it normally.