Add standard for KaaS networking requirements

Signed-off-by: Konrad Gube <[email protected]>

Author: kgube

Standards/scs-XXXX-v1-kaas-networking.md

@@ -0,0 +1,61 @@
+---
+title: KaaS Networking Standard
+type: Standard
+status: Draft
+track: KaaS
+---
+
+## Introduction
+
+Kubernetes defines a networking model that needs to be implented by a separate CNI plugin.
+Beyond basic connectivity within the cluster, however, there are many networking features that are specified but optional.
+Some of these optional features provide vital functionality, such as the NetworkPolicy API and the Ingress API.
+
+This standard specifies a minimal set of networking features that users can expect in clusters created by an SCS complient KaaS provider.
+
+## Terminology
+
+Example (abbr. Ex)
+  This is the description for an example terminology.
+
+## Motivation
+
+KaaS providers will typically support aditional networking functionality beyond basic Kubernetes networking.
+The specific range features depends on the used CNI plugin, but may also be extended by additional operators.
+Users may expect certain optional functionality, so we should define a baseline feature set that has to be available in an SCS-compliant KaaS cluster.
+
+## Design Considerations
+
+- Avoid mandating features specific to certain CNI plugins (like CiliumClusterwideNetworkPolicy)
+
+### Options considered
+
+#### NetworkPolicy API
+
+- Should be a requirement
+- We need to be specific about which API version to require and reference the upstream definition
+- Only recommend recent additions like AdminNetworkPolicy
+
+#### Ingress API
+
+- Some CNI plugins (specifically Cilium) have builtin support for the Ingress and Gateway API
+- Those can also be provided by separate ingress controllers (like ingress-nginx)
+- Ingress controllers seem to be regularly requested by managed k8s users
+- some users may prefer to deploy their own ingress controllers
+
+### Open questions
+
+RECOMMENDED
+
+## Standard
+
+CSPs MUST provide a network plugin that supports the basic NetworkPolicy API
+CSPs SHOULD provide a network plugin that implements the AdminNetworkPolicy and BaselineAdminNetworkPolicy resources.
+
+## Related Documents
+
+Related Documents, OPTIONAL
+
+## Conformance Tests
+
+Conformance Tests, OPTIONAL