I don't scale out to a hundred servers and I still use Docker with separate processes because scaling is not the only advantage to having stateless single-purpose containers.

Single purpose is a role.

Single process is a single process. [e.g. Nginx]

I think you are confused by what I meant.

Stateless single purpose containers is good. One process per container is bad because it involves more service discovery before you actually need it.

I run several processes on each VM, each in their own container, and use Docker links which exposes environment variables into each container describing ip/port information for dependent services. It was really easy and works great.

Furthermore, you can easily set all of the containers to share the same networking namespace so they can all just listen locally if you wanted a turn key solution. The pretty trivial issue of single-host service discovery is not a very strong argument against the benefits of single process containers in my experience.

In order to do things your way you need:

1) Multiple docker containers to spin up and be managed.

2) Multiple health checks.

3) Set additional flags/do additional config for Docker.

The fact people consistently say "Eh, this is a non-issue" is great. It means you are much luckier and more skilled than I since you can manage all of that with 0 additional effort.

For me, all of this is effort I don't need to expend.