To configure sentinel.conf at run-time
docker run joshula/redis-sentinel --[config A] --[config B]
Important: the you must bind ports (-p) and set the (sentinel announce-ip) and (sentinel-announce-port) parameters in sentinel.conf for Sentinel to work in a container environment.
Here's an example of what that looks like:
docker run -p 26379:26379 joshula/redis-sentinel --sentinel announce-ip 1.2.3.4 --sentinel announce-port 26379