[routing rules](https://istio.io/latest/docs/reference/config/networking/) into proxy specific configuration.

    - [security](security/). This directory contains [security](https://istio.io/latest/docs/concepts/security/) related code,
including Citadel (acting as Certificate Authority), citadel agent, etc.

- [istio/proxy](https://github.com/istio/proxy). The Istio proxy contains