cilium CNI cannot be used in combination with bandwidth CNI

[nayihz]

Is there an existing issue for this?

• I have searched the existing issues

What happened?

In my testing environment, I tested the scenario of using cilium and bandwidth CNI together(we cannot use cilium bandwidthManager because our os kernel version is too low to meet the requirements.). Then we found that an error occured when bandwith CNI was called: no veth peer of container interface found in host ns.

After reivewing the bandwith CNI source code, the reason for this error is that the result returned by cilium CNI does not meet the following containtion.
https://github.com/containernetworking/plugins/blob/4a6147a1552064af80b4f7567b30c5174153c62a/plugins/meta/bandwidth/main.go#L153-L160

for _, iface := range interfaces {
    if iface.Sandbox == "" && iface.Name == link.Attrs().Name {
	return iface, nil
    }
}

The official documentation of CNI requires that the interfaces field should include information about both container-side interface and host-side interface. However, currently cilium only provides the container-side interface information.

https://www.cni.dev/docs/spec/#section-5-result-types

• interfaces: An array of all interfaces created by the attachment, including any host-level interfaces:
  • name: The name of the interface.
  • mac: The hardware address of the interface (if applicable).
  • sandbox: The isolation domain reference (e.g. path to network namespace) for the interface, or empty if on the host. For interfaces created inside the container, this should be the value passed via CNI_NETNS.

some test code:

+       log.Println("interfaces length:", len(interfaces))
        for _, iface := range interfaces {
+               log.Println("iface name:", iface.Name)
+               log.Println("sandbox: ", iface.Sandbox)
+               log.Println("link.Attrs().Name: ", link.Attrs().Name)
                if iface.Sandbox == "" && iface.Name == link.Attrs().Name {
                        return iface, nil
                }
        }

output:

2023/04/13 07:20:51 interfaces length: 1
2023/04/13 07:20:51 iface name: eth0
2023/04/13 07:20:51 sandbox:  /var/run/netns/cni-882cb34f-9dd9-6014-556b-724e5d2e383d
2023/04/13 07:20:51 link.Attrs().Name:  lxc1986c9428372

Cilium Version

1.13.0

Kernel Version

5.15.0-69-generic

Kubernetes Version

Client Version: version.Info{Major:"1", Minor:"26", GitVersion:"v1.26.3", GitCommit:"9e644106593f3f4aa98f8a84b23db5fa378900bd", GitTreeState:"clean", BuildDate:"2023-03-15T13:40:17Z", GoVersion:"go1.19.7", Compiler:"gc", Platform:"linux/amd64"}
Kustomize Version: v4.5.7
Server Version: version.Info{Major:"1", Minor:"26", GitVersion:"v1.26.3", GitCommit:"9e644106593f3f4aa98f8a84b23db5fa378900bd", GitTreeState:"clean", BuildDate:"2023-03-15T13:33:12Z", GoVersion:"go1.19.7", Compiler:"gc", Platform:"linux/amd64"}

Sysdump

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Relevant log output

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Anything else?

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Code of Conduct

• I agree to follow this project's Code of Conduct

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Closing.