Network security for microservices with eBPF

Several open-source Kubernetes tools are already using eBPF. Mainly related to networking, monitoring, and security.
The intention of this post is not to provide complete coverage of all eBPF aspects, but rather tries to be a informational starting point guide, from the understanding of Linux kernel BPF concept, through the advantages and features that brings to microservices environments, to some known tools that currently make use of it, such Cilium or Weave.

Understanding eBPF