Network Plugins: --network-plugin flag is missing in 1.24.0, yet documented as available

[netikras]

ref: https://kubernetes.io/docs/concepts/extend-kubernetes/compute-storage-net/network-plugins/

[root@CentOS-83-64-minimal ~]# kubelet --version
Kubernetes v1.20.4
[root@CentOS-83-64-minimal ~]# kubelet --help | grep network-plugin
      --network-plugin string                                    The name of the network plugin to be invoked for various events in kubelet/pod lifecycle. This docker-specific flag only works when container-runtime is set to docker.
      --network-plugin-mtu int32                                 The MTU to be passed to the network plugin, to override the default. Set to 0 to use the default 1460 MTU. This docker-specific flag only works when container-runtime is set to docker.
[root@CentOS-83-64-minimal ~]# 

root@netikras-hub:/etc/systemd/system/kubelet.service.d# kubelet --version
Kubernetes v1.24.0
root@netikras-hub:/etc/systemd/system/kubelet.service.d# kubelet --help | grep network-plugin
root@netikras-hub:/etc/systemd/system/kubelet.service.d# 
root@netikras-hub:/etc/systemd/system/kubelet.service.d# kubelet --network-plugin=cni 2>&1 | head -3
Error: failed to parse kubelet flag: unknown flag: --network-plugin
Usage:
  kubelet [flags]
root@netikras-hub:/etc/systemd/system/kubelet.service.d# 

[mk46]

/sig node
/kind cleanup
If any flag found which was removed in kubernetes/kubernetes#106907, Kindly remove them too.

[sftim]

/triage accepted

[sftim]

/language en

[angelosnm]

For anyone facing this issue and Kubernetes is not starting, I removed the --network-plugin flag from /var/lib/kubelet/kubeadm-flags.env file and restarted kubelet service. (systemctl restart kubelet).

[sftim]

/priority important-longterm

[sftim]

Folks, this is an accepted issue. We should update that page to remove mentions of the --network-plugin command line argument.

Pull requests are welcome - see https://kubernetes.io/docs/contribute/ for tips on how to contribute.

[sftim]

I've marked some off-topic comments as hidden. They're not deleted (you can click Show comment to reveal them). Please, folks, do focus on the topic here: fixing the Kubernetes documentation about setting up cluster networking

[sftim]

If anyone has questions about how to propose a fix for https://kubernetes.io/docs/concepts/extend-kubernetes/compute-storage-net/network-plugins/, you're very welcome to ask. You can reply here or, if you use the Kubernetes workspace for Slack, ask there in the #sig-docs channel.

[netikras]

I've created a SO page to redirect all the "how to fix my cluster now" questions there: https://stackoverflow.com/questions/72316016/after-upgrading-to-kubelet-v1-24-clusted-does-not-start . Should I update the OP to reflect this link and state that this is not a request to fix the cluster's setup? @sftim

[sftim]

Duplicated by issue #33862

[sftim]

We should edit https://kubernetes.io/docs/concepts/extend-kubernetes/compute-storage-net/network-plugins/ so that it is no longer incorrect, and then close this issue.

[sftim]

Anyone who wants to edit that page is welcome to.

[tomkivlin]

/assign

[rolfedh]

@mikebrow is reviewing @tomkivlin's PR #33870

[duanhaowei]

remove " --network-plugin"flag work fine.

[mperlik]

For anyone facing this issue and Kubernetes is not starting, I removed the --network-plugin flag from /var/lib/kubelet/kubeadm-flags.env file and restarted kubelet service. (systemctl restart kubelet).

This resulted in my case just in another error:

Jun 19 09:15:47 k8s-1m kubelet[1752935]: W0619 09:15:47.044045 1752935 clientconn.go:1331] [core] grpc: addrConn.createTransport failed to connect to {  <nil> 0 <nil>}. Err: connection error: desc = "transport: Error while dialing dial unix: missing address". Reconnecting...
Jun 19 09:15:47 k8s-1m kubelet[1752935]: Error: failed to run Kubelet: unable to determine runtime API version: rpc error: code = Unavailable desc = connection error: desc = "transport: Error while dialing dial unix: missing address"

[sftim]

As this bug is resolved, I'm going to lock it to ensure that the record remains on-topic.