I’ve had Caddy running nicely under Docker for some time and discovered several days ago that the Docker container was spinning on start complaining with:
Activating privacy features... 2016/09/26 01:11:57 [<dns name>] failed to get certificate: acme: Error 429 - urn:acme:error:rateLimited - Error creating new cert :: Too many certificates already issued for exact set of domains: <dns name>
Every host having TLS served by Caddy is attempting to create a new certificate and I’m unable to start Caddy successfully, inside or outside Docker.
The only error output I have is that above. Does anyone have any suggestions on why this happened (I didn’t change anything, but possibly restarted the Caddy container) and how to start the services again?
One frequent cause of this issue, especially with Caddy in Docker, would be failing to save the certificates directory properly, causing Caddy to have to acquire a new set of certificates on each reboot. This would quickly hit the rate limits.
As per the LetsEncrypt website (see: Rate Limits - Let's Encrypt), there’s no way to reset your rate limit for this week. A workaround in the meantime would be to configure your Caddyfile to serve your sites over HTTP (assuming you haven’t configured HSTS or have 301 redirects cached).
You may also want to configure Caddy to use the LetsEncrypt staging endpoint (see: Staging Environment - Let's Encrypt) to test while you sort out exactly what the cause is.