We are moving from a single Caddy node setup to a cluster setup with multiple nodes.
Our nodes are not going to be in the same private network, they are actually not even in the same datacenter. To be able to complete ACME challenges from Let’s Encrypt the nodes need to use a shared storage facility such as S3 or Redis. I have read up on similar posts in this forum, and from what I read sharing storage through a plugin seems pretty straight forward.
But I have one concern that I can not find answers to, so I thought I would ask it here: Are the obtained certificates solely stored in the shared storage facility, or are they also being cached locally on the individual node? If they are not cached, does this mean that the shared storage facility is being hit every time a request comes though? This would introduce a single point of failure, and in our use case lot’s of latency.
If the answer to my question is simply “of course they are cached, stupid” I apologize in advance