SE-Radio 341: Michael Hausenblas on Container Networking

Overlay Networks

Overlay networks are a crucial component in container networking, providing a virtual network layer on top of existing physical infrastructure. Michael Hausenblas explains that these networks are highly configurable, allowing for flexibility and scalability in container environments. He notes that Docker's overlay network, for instance, includes a built-in key-value store to manage state and assignments 1.

Overlay networks essentially define a virtual network, a software-defined network on top of the underlying physical network.

--- Michael Hausenblas

The discussion also highlights the variety of network plugins available, such as Calico, Flannel, and Weavenet, which offer different functionalities and integrations with Docker and Kubernetes 2 3.

   

Plugins

Network plugins play a vital role in enabling seamless communication between containers across different hosts. Michael Hausenblas describes how Docker provides default plugins like MacvLAN and IPVLAN, as well as third-party options like Calico and Flannel 4. These plugins address the challenge of IP address management, especially in large-scale environments with numerous containers.

The challenge is the combination of scale and speed; you need to manage a large number of IP addresses quickly.

--- Michael Hausenblas

Hausenblas emphasizes that while IPV6 adoption is slow, it could simplify IP management in the future 2.