Docker: Creating Structured Containers

Networking with overlay networks – Flannel

Flannel is the virtual network layer that provides the subnet to each host for use with Docker containers. It is packaged with CoreOS but can be configured on other Linux OSes as well. Flannel creates the overlay by actually connecting itself to Docker bridge, to which containers are attached, as shown in the following figure. To setup Flannel, two host machines or VMs are required, which can be CoreOS or, more preferably, Linux OS, as shown in this figure:

The Flannel code can be cloned from GitHub and built locally, if required, on a different flavor of Linux OS, as shown here. It comes preinstalled in ...