Thanks to Justin Garrison, I recently not only finally understand

• how to setup Kubernetes networking on baremetal from scratch,

but also

• how to jump into a running pod's containers

and peek around!

In brief:

• locate the container's Docker name using docker ps (last entry, very long, probably starting with k8s_)
• run a debugging container of your choice in the same PID namespace, e.g.:

docker run -it --pid=container:<container docker name> alpine sh

• cd into /proc/1/root directory
• explore!

For more details, read his Medium post.