Configuring an overlay network with the Docker Engine swarm node
With the release of Docker 1.9, the multi-host and overlay network has become one of its primary feature. It enables private networks that can be established to connect multiple containers. We will be creating the overlay network on a manager node running in swarm cluster without an external key-value store. The swarm network will make the network available to the nodes in the swarm that require it for a service.
When we deploy the service that uses overlay network, the manager automatically extends the network to the nodes that are running the service tasks. Multi-host networking requires a store for service discovery, so now we will create a Docker machine to run this service.