Multus 4.0.2 delegates to itself, breaking networking

EyeCantCU commented 2 weeks ago

What happend:

The very first network configuration file is selected as the delegate. This file is always 00-multus.conf in /etc/cni/net.d/. 10-calico.conflist is then correctly appended to 00-multus.conf

When restarting the multus pod, it appends the configuration for 00-multus.conf to all delegates (now including itself), breaking networking. Restart after restart, the file gets larger and larger due to this

What you expected to happen:

Multus would not delegate to itself

How to reproduce it (as minimally and precisely as possible):

Install RKE2
Deploy Calico with Tigera operator
Fetch daemonset config: curl -O https://raw.githubusercontent.com/k8snetworkplumbingwg/multus-cni/master/deployments/multus-daemonset.yml
Sub in 4.0.2: `sed -i 's+ghcr.io/k8snetworkplumbingwg/multus-cni:snapshot+ghcr.io/k8snetworkplumbingwg/multus-cni:v4.0.2+' multus-daemonset.yml``
Apply the daemonset: kubectl apply -f multus-daemonset.yml
At this point, we have a working setup
Restart the kube-multus pod <- this is where things break

Multus will have delegated to itself breaking networking

Anything else we need to know?:

Rancher provides a patch that addresses this: https://github.com/rancher/image-build-multus/blob/v4.0.2-build20231009/self_delegation_bug.patch

Would this be possible to apply in a 4.0.3 patch release?

Environment:

Multus version, image path, and image ID (from 'docker images'): ghcr.io/k8snetworkplumbingwg/multus-cni:v4.0.2
Kubernetes version (use kubectl version): 1.31.0
Primary CNI for Kubernetes cluster: Calico

mamccorm commented 2 weeks ago

There may already be a similar fix for this in the v4.1 release, but due to dependencies it'd be great to get this back-ported to v4.0.2. As there's no branch for v4.0.2, here's a proposal:

https://github.com/k8snetworkplumbingwg/multus-cni/compare/v4.0.2...mamccorm:multus-cni:fix/append-cni-configs

franpog859 commented 1 week ago

I see it already being reported here - https://github.com/k8snetworkplumbingwg/multus-cni/issues/1130 - and fixed here - https://github.com/k8snetworkplumbingwg/multus-cni/commit/159f2610c0775a3d22fb1109786dab5ef33bb9f7 - It's released in 4.1.0 version

It'd be great to see it backported to 4.0.3 version too. @mamccorm , is your proposal going to be worked on?

dougbtv commented 1 day ago

Looks like it's fixed up, thanks for the report

k8snetworkplumbingwg / multus-cni

Multus 4.0.2 delegates to itself, breaking networking #1324