Enabling node-to-node communication through k8s' cluster-to-cluster connections

[CunliangGeng]

Evaluate existing solutions (e.g. SKUPPER.io, Istio service mesh) for K8S cluster-to-cluster connection as the means for enabling node-to-node communication.

• Setting up a test environment for the evaluation.
• Test connectivity, e.g., exposing a simple web server on a POD on cluster A, and do a 'curl' to it from a POD on cluster B.
• Compare this with the VPN-based approach currently followed by v6-node. (doc link)
• Evaluate which v6 node-configuration settings could be used or should be added to ensure only 'whitelisted' connections are allowed.

Relevant

• code https://github.com/bdh-generalization/v6-on-kubernetes-PoC/blob/main/avg_alg/app.py
• read doc to understand how VPN approach works https://docs.vantage6.ai/en/main/features/inter-component/vpn.html

Requirements:

• the traffic does not have to go through the "Proxy Server" (see fig2)
• algorithm container is not allowed to connect to internet
  • and should be able to connect to the service mesh then to another algorithm
• ensure that the service mesh is decoupled with setup of v6 (node)
• user could choose which service mesh to use (e.g. skupper, istio), make sure it is part of the Cloud native computing foundation https://www.cncf.io/projects/