How to access a docker service from public net (internet)?

Docker swarm,
Setup: only the master node (public ip: and intranet ip: is on the internet and the worker nodes (intranet ip’s: and are on the intranet.

Service creation-

$docker service create   
  --name my-nginx 
  --network my-overlay 
  --replicas 1 
  -p 8080:80 

Now, does hitting from the internet work?
If it does then what is the role of routing mesh here?

Source: StackOverflow