In the chapter on Redis Cluster and Sentinel we didn't cover some major issues that can occur when trying to deploy Redis's high availability solution when using Docker. Docker performs a dynamic port reallocation when using the –p directive when launching a new Docker container. Sentinel's auto discovery of other running Sentinel process as well as discovering a list of slaves from a master assumes a fixed port numbers, this Sentinel feature will break if the internally running Sentinel on a Docker container is mapped to a different port.
To use Sentinel with Docker you have two options: the first is to update the
sentinel announce-ip and
sentinel announce-port for each of Docker container running Sentinel so that the Docker ...