Docker has several types of networks, but one of them is particularly interesting. Overlay network can span across hosts boundaries, so your web application container at HostA can easily talk to database container at HostB by its name. It doesn’t even have to know where that container is.
Unfortunately, you can’t just create overlay network and hope that it magically finds out about all participating hosts. There should be one more component in order to make that happen.
Of cause, we could use Docker in Swarm mode and problem’s solved. But we don’t have to. Configuring multi-host Docker network without Swarm is actually quite easy. Continue reading “Multi-host Docker network without Swarm”