How to Telnet Memcache Port

Currently, only port 11212 is exposed to the outside for the memcache. You can telnet to the memcache port 11212 with the command: 
telnet <docker host IP> 11212

The docker host IP can be found from the command echo $DOCKER_HOST if docker-machine is used. Otherwise, it's the machine/vm IP.

If you need to telnet to other memcache ports, you need to add the port mapping in the docker-compose.yml file and restart the docker-compose. Then, use the command: 
telnet <docker host IP> <port number>
Alternatively, you could get in the memcache container with the command: 
docker exec -it ml_mem /bin/bash
Install the telnet there and then use the command: 
telnet localhost <port number>