
Generally you won’t need to think about how this network functions. When a pod talks with another pod it most often does so through the abstraction of a service, a kind of software-defined proxy that will be the subject of the next post in this series. But pod network addresses will pop up in logs and when debugging and in some scenarios you may nee…
… thing that should jump out is that I’ve changed the name of the bridges from “docker0” to “cbr0.” Kubernetes does not use the standard docker bridge device and in fact “cbr” is short for “custom bridge.” I don’t know everything that is custom about it, but it is one of the important differences between docker running on kubernetes vs. a default installation. Another thing to note is that the address space assigned to the bridges in this example is 10.0.0.0…
Kubernetes implements this pattern by creating a special container for each pod whose only purpose is to provide a network interface for the other containers. If you ssh in to a kubernetes cluster node that has pods scheduled on it and run docker ps you will see at least one container that was started with the pause command. The pause command suspends the current process until a signal is received so these containers do no…