In dual-stack mode --node-ip to kubelet only have one address about k0sctl HOT 5 OPEN

I don't think k0s passes any --node-ip flags to kubelet at all. According to the CLI flag's description, it defaults to IPv4. That's what you're seeing in your cluster, I suppose.

  --node-ip string                                           IP address (or comma-separated dual-stack IP addresses) of the node. If unset, kubelet will use the node's default IPv4 address, if any, or its default IPv6 address if it has no IPv4 addresses. You can pass '::' to make it prefer the default IPv6 address rather than the default IPv4 address.

You could pass your own values via --kubelet-extra-args=--node-ip=... in spec.hosts[*].installFlags for the time being.

/cc @ncopa WDYT about this?

from k0sctl.

I don't think k0s passes any --node-ip flags to kubelet at all.

@twz123 You are right. I specified privateAddress:. If I remove that, no "--node-ip" is passed to kubelet.

vm-002 ~ # ps www | grep kubelet
  464 root     1267m S    /var/lib/k0s/bin/kubelet --root-dir=/var/lib/k0s/kubelet --config=/var/lib/k0s/kubelet-config.yaml --kubeconfig=/var/lib/k0s/kubelet.conf --v=1 --cert-dir=/var/lib/k0s/kubelet/pki --containerd=/run/k0s/containerd.sock --runtime-cgroups=/system.slice/containerd.service

But for dual-stack it seems that you must specify "comma-separated dual-stack IP addresses" to get it right:

vm-002 ~ # k0s kubectl get node $(hostname) -o json | jq .status.addresses
[
  {
    "address": "192.168.1.2",
    "type": "InternalIP"
  },
  {
    "address": "vm-002",
    "type": "Hostname"
  }
]

(ipv6 is missing)

from k0sctl.

If it's connected to privateAddress, then it's probably something in k0sctl, not in k0s itself ... Indeed, it is: https://github.com/k0sproject/k0sctl/blob/v0.18.1/pkg/apis/k0sctl.k0sproject.io/v1beta1/cluster/host.go#L320-L327

Not sure what to do here, since the IPv6 is not part of the k0sctl config at all. /cc @kke How would k0s or k0sctl know which IP to use if it isn't specified? Sure, there could be some magic auto-detection, but less magic is usually preferable. Would it make sense to make privateAddress a list and accept multiple IPs, or is that a bad idea? 🤔

from k0sctl.

You could pass your own values via --kubelet-extra-args=--node-ip=... in spec.hosts[*].installFlags for the time being.

Yes, that works 😃

vm-002 ~ # k0s kubectl get node $(hostname) -o json | jq .status.addresses
[
  {
    "address": "192.168.1.2",
    "type": "InternalIP"
  },
  {
    "address": "fd00::c0a8:102",
    "type": "InternalIP"
  },
  {
    "address": "vm-002",
    "type": "Hostname"
  }
]

I removed privateAddress: and instead specified:

    installFlags:
    - "--kubelet-extra-args=--node-ip=192.168.1.2,fd00::192.168.1.2"

If privateAddress: is only used for passing an address to kubelet via --node-ip, it should take comma-separated dual-stack IP addresses, same as kubelet.

For a better user experience, k0sctl may specify the first IPv4 and the first global IPv6 for "privateInterface:" as --node-ip if dual-stack is enabled.

This problem should be documented in any case.

I am happy with this work-around, and you may close this issue if you like, or keep it for reference.

from k0sctl.

see also k0sproject/k0s#3954

from k0sctl.