This article discusses the evolution of external controllers for containers and virtual machines.
This column will be the first of three columns discussing the evolution of external controllers for containers and virtual machines. First and foremost, it is very important that the frameworks are separated from the virtual machines and containers, such as the plug-in model that was recently announced. In this column, I'll discuss the networking framework that is evolving from the application-centric cloud through the use of VMs and containers.
I believe the future of the data center is to create a subsystem that takes a core piece of technology and allows users and third-party companies to extend its functionality, such as volume, storage, or networking, thus giving the developer the ability to extend the newer frameworks with existing frameworks. The rapid and evolutionary changes to the ecosystem have created a need for control of an SDN (software-defined network) model or cloud fabric model for the new applications being developed in the application-centric cloud.
SDN, which was born at Stanford with the concept of open flow, has grown with the OpenDaylight project. The new networking stack creates a logical network without a network controller. The technology, known as SocketPlane, was acquired by Docker and is the abstraction model for networking with containers.
At the last DockerCon, the concept of plug-ins was announced, and other companies joined the fray in creating network plug-ins. Weave, for example, creates a virtual network that connects containers deployed across multiple hosts and enables their automatic discovery. Most customers in the application-centric cloud described here will have connectivity with Cisco's ACI and connectivity with VMWare's NSX. In some cases, these customers want to have both, inside the same logical network.
The industry has started to build a general-purpose architecture that leaves the core layer that unites application-centric containers with the network -- witness NSX and ACI creatingthe ability to network virtual machines. The original networking concept in containers was very limited. Therefore, the community has started to create a logical network on its plane, using IP/v4, that will eliminate the overall need for layer 2 in the OSI model.