Networking and Kubernetes

Chapter 3. Container Networking Basics

Now that we’ve discussed networking basics and Linux networking, we’ll discuss how networking is implemented in containers. Like networking, containers have a long history. This chapter will review the history, discuss various options for running containers, and explore the networking setup available. The industry, for now, has settled on Docker as the container runtime standard. Thus, we’ll dive into the Docker networking model, explain how the CNI differs from the Docker network model, and end the chapter with examples of networking modes with Docker containers.

Introduction to Containers

In this section, we will discuss the evolution of running applications that has led us to containers. Some, rightfully, will talk about containers as not being real. They are yet another abstraction of the underlying technology in the OS kernel. Being technically right misses the point of the technology and leads us nowhere down the road of solving the hard problem that is application management and deployment.

Applications

Running applications has always had its challenges. There are many ways to serve applications nowadays: in the cloud, on-prem, and, of course, with containers. Application developers and system administrators face many issues, such as dealing with different versions of libraries, knowing how to complete deployments, and having old versions of the application itself. For the longest time, developers of applications had to deal with ...