docs: add cilium and overlay docs (#1684)

* docs: add cilium and overlay docs

* docs: fix missing link title

* docs: update wording on cilium

README.md

@@ -23,6 +23,8 @@ The following environments are supported:
 
 Plugins are offered as part of [Azure Kubernetes Service (AKS)](https://docs.microsoft.com/en-us/azure/aks/), as well as for individual Azure IaaS VMs. For Kubernetes clusters created by [aks-engine](https://github.com/Azure/aks-engine), the deployment and configuration of both plugins on both Linux and Windows nodes is automatic and default.
 
+The next generation of Azure CNI Plugin is powered by [Cilium](https://cilium.io/). Learn more at [Azure CNI Powered By Cilium](docs/cilium.md)
+
 ## Documentation
 See [Documentation](docs/) for more information and examples.
 

docs/README.md

@@ -2,6 +2,8 @@
 
 ## Table of Contents
 * [CNI plugin](cni.md) - describes how to setup Azure CNI plugins.
+* [Azure CNI Powered By Cilium](cilium.md) - describes the next generation of Azure CNI Plugin powered by Cilium dataplane.
+* [Azure CNI Overlay Mode for AKS](overlay-for-aks.md) - describes a mode of the Azure CNI Plugin to provide a Pod network from an overlay address space with no encapsulation.
 * [CNM (libnetwork) plugin](cnm.md) - describes how to setup Azure CNM plugins.
 * [ACS](acs.md) - describes how to use the plugins with Azure Container Service.
 * [Network](network.md) - describes container networks created by plugins.

docs/cilium.md

@@ -0,0 +1,7 @@
+# Azure CNI Powered By Cilium
+
+Azure CNI powered by [Cilium](https://cilium.io/) provides native support for the next generation Cilium eBPF dataplane in AKS clusters running Azure CNI. It offers Pod networking, highly scalable [Kubernetes Network Policies](https://kubernetes.io/docs/concepts/services-networking/network-policies/), and high performance service load balancing with eBPF. The eBPF dataplane is available in both [VNet mode](https://learn.microsoft.com/en-us/azure/aks/configure-azure-cni#dynamic-allocation-of-ips-and-enhanced-subnet-support) and [Overlay mode](https://learn.microsoft.com/en-us/azure/aks/azure-cni-overlay) of Azure CNI.
+
+## Learn More
+[Blog Post: Azure CNI Powered by Cilium for Azure Kubernetes Service (AKS)](https://techcommunity.microsoft.com/t5/azure-networking-blog/azure-cni-powered-by-cilium-for-azure-kubernetes-service-aks/ba-p/3662341)
+

docs/overlay-for-aks.md

@@ -0,0 +1,6 @@
+# Azure CNI Overlay Mode for AKS
+
+Azure CNI Overlay mode is a new CNI network plugin that allocates pod IPs from an overlay network space, rather than from the virtual network IP space. This greatly reduces the IP utilization of Azure CNI as compared to the default mode. This CNI plugin functions like “kubenet” mode, but does not utilize route tables and thus is simpler to set up and much more scalable.
+
+## Learn More
+[Azure Documentation: Configure Azure CNI Overlay networking in Azure Kubernetes Service (AKS)](https://aka.ms/aks/azure-cni-overlay)