If you have not used Swarm, skim the non-service-discovery tutorial to get a feel for how it works:
https://blog.vpetkov.net/2015/12/07/docker-swarm-tutorial-and-examples. It’s very easy, and it should give you an idea of how it works within a couple of minutes.
Using Swarm with pre-generated static tokens is useful, but there are many benefits to using a service discovery backend. For example, you can utilize network overlays and have common “bridges” that span multiple hosts (https://docs.docker.com/engine/userguide/networking/get-started-overlay/). It also provides service registration and discovery for the Docker containers launched into the Swarm. Now lets get into how to use it with service discovery – which is what you would use in a scaled out environment/production.
Again, assuming you have a bunch of servers running docker:
vm01 (10.0.0.101), vm02 (10.0.0.102), vm03 (10.0.0.103), vm04 (10.0.0.104)
Normally, you can do “docker ps” on each host for example:
ssh vm01 ‘docker ps’
ssh vm04 ‘docker ps’
If you enable the API for remote bind on each host you can manage them from a central place:
docker -H tcp://vm01:2375 ps
docker -H tcp://vm04:2375 ps
(note: port is optional for default)
But if you want to use all of these docker engines as a cluster, you need Swarm.
Here we will go one step further and use a common service discovery backend (Consul).