Traffic shaping (bandwidth CNI plugin) does not work with cni: flannel

[brandond]

Environmental Info:
RKE2 Version:
n/a

Node(s) CPU architecture, OS, and Version:
linux

Cluster Configuration:
n/a

Describe the bug:
Cannot follow upstream instructions to enable traffic shaping:
https://kubernetes.io/docs/concepts/extend-kubernetes/compute-storage-net/network-plugins/#support-traffic-shaping

Steps To Reproduce:

1. Install RKE2 with flannel CNI
2. Deploy pod with bandwidth annotations

Expected behavior:
bandwith plugin is executed to set traffic limits on network namespace

Actual behavior:
Fails because rke2-flannel CNI config lacks bandwidth plugin config

Additional context / logs:
May also be an issue for other CNIs, I haven't actually tested.

[manuelbuil]

I think the issue is mostly about making both RKE2 and K3s config the same. There are certain "meta" cni plugins: https://github.com/containernetworking/plugins/tree/main/plugins/meta which you can stack together with the main cni plugin. But I don't think we should add all of them by default to network plugins

[brandond]

Yeah but you need to enable bandwidth in the CNI config for the Kubernetes feature to work properly. At the moment I don't think it'll work

Ref:

• Bump cni plugins to v1.2.0-k3s1 k3s-io/k3s#7425