Running DCOS (data center operating system) on AWS is a snap, and solves all these problems. It makes running docker images a no-brainer compared to all other solutions, and this includes docker images that interact with one another (not just 100 apache servers or whatever). It is the best software I have ever used, hands down. It is the second coming of zeus buddha jesus belly. It makes scaling anything in the cloud easy. No, I do not work there. No, I am not exaggerating. Yes, I spent a month fucking with swarm and service discovery before deploying a large cluster of my service in two days on DCOS.
Docker is stuck in the 'one image on one machine' mindset. DCOS is taking over at the higher levels of the stack. Mark my word.