Multus CNI vs Network Service Mesh

Multus CNI has no write-up on Specifiction yet; its figures are above.

Network Service Mesh connects workloads across clusters and clouds through a hybrid, multi-cloud IP service mesh. Each workload can connect independently to zero or more Network Services, regardless of where it runs. The project says it works with an existing CNI without requiring changes to Kubernetes or workloads. Services can provide connectivity, security, and observability at Layer 3 and above, carrying IP or Ethernet payloads.

Clients may be Kubernetes pods, virtual machines, or physical servers. They authenticate independently, currently using SPIFFE IDs, and need authorization to attach. Clients request and close virtual wires over gRPC and can monitor connection status through a streaming call. Endpoint selection offers composition, selective composition, topology awareness, and scale from zero. A service may also provide domain-scoped DNS for connected pods. The architecture describes integration with Istio, Linkerd, Consul, and Kuma. Network Service Mesh is a CNCF sandbox project and is free and open source. Its run guide lists Docker, Go, a Kubernetes cluster, and kubectl as prerequisites; most examples require at least two worker nodes.