[Release-1.23] In case of NodeIP not specified with dualstack setup K3S fails to start

[rbrtbnfgl]

Backport for #5918

[mdrahman-suse]

Validated on 1.23 branch with commit d04af60

Environment Details

Infrastructure

• Cloud
• Hosted

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

Linux ip-192-168-7-155 5.15.0-1011-aws #14-Ubuntu SMP Wed Jun 1 20:54:22 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux
PRETTY_NAME="Ubuntu 22.04 LTS"
NAME="Ubuntu"
VERSION_ID="22.04"
VERSION="22.04 LTS (Jammy Jellyfish)"

Cluster Configuration:

Single node

Config.yaml:

write-kubeconfig-mode: 644
token: summer
cluster-cidr: 10.42.0.0/16,2001:cafe:43:0::/56
service-cidr: 10.43.0.0/16,2001:cafe:44:1::/112
flannel-iface: "ens5"
disable-network-policy: true
flannel-ipv6-masq: true
cluster-init: true

Testing Steps

1. Copy config.yaml

$ sudo mkdir -p /etc/rancher/k3s && sudo cp config.yaml /etc/rancher/k3s

2. Install k3s

• For replication: curl -sfL https://get.k3s.io | INSTALL_K3S_VERSION=v1.23.9+k3s1 sh -
• For validation: curl -sfL https://get.k3s.io | INSTALL_K3S_COMMIT=d04af60aad053ec94e60c986bf4c70cdbfc9e11c sh -

3. Ensure k3s cluster is up

Replication Results:

• k3s version used for replication:

k3s version v1.23.9+k3s1 (f45cf326)
go version go1.17.5

• The cluster does not come up as k3s fails to start and the below error is observed

$ journalctl -xeu k3s.service | grep 'cluster-cidr:'
Aug 10 05:13:53 ip-192-168-7-155 k3s[1865]: time="2022-08-10T05:13:53Z" level=fatal msg="cluster-cidr: [10.42.0.0/16 2001:cafe:43::/56] and node-ip: [192.168.7.155], must share the same IP version (IPv4, IPv6 or dual-stack)"
Aug 10 05:14:07 ip-192-168-7-155 k3s[1882]: time="2022-08-10T05:14:07Z" level=fatal msg="cluster-cidr: [10.42.0.0/16 2001:cafe:43::/56] and node-ip: [192.168.7.155], must share the same IP version (IPv4, IPv6 or dual-stack)"

Validation Results:

• k3s version used for validation:

k3s version v1.23.9+k3s-d04af60a (d04af60a)
go version go1.17.5

• The cluster comes up successfully and no error is observed

$ journalctl -xeu k3s.service | grep 'cluster-cidr:'

$ kubectl get nodes,pods -A -o wide
NAME                    STATUS   ROLES                       AGE   VERSION                INTERNAL-IP     EXTERNAL-IP   OS-IMAGE           KERNEL-VERSION    CONTAINER-RUNTIME
node/ip-192-168-7-155   Ready    control-plane,etcd,master   48s   v1.23.9+k3s-d04af60a   xxx.xxx.x.155   <none>        Ubuntu 22.04 LTS   5.15.0-1011-aws   containerd://1.5.13-k3s1

NAMESPACE     NAME                                          READY   STATUS      RESTARTS   AGE   
kube-system   pod/coredns-d76bd69b-jclws                    1/1     Running     0          39s   
kube-system   pod/helm-install-traefik-99wg4                0/1     Completed   2          39s   
kube-system   pod/helm-install-traefik-crd-87wbm            0/1     Completed   0          39s   
kube-system   pod/local-path-provisioner-6c79684f77-8lxwk   1/1     Running     0          39s   
kube-system   pod/metrics-server-7cd5fcb6b7-nf5c9           1/1     Running     0          39s   
kube-system   pod/svclb-traefik-150fb572-qstsp              2/2     Running     0          7s    
kube-system   pod/traefik-df4ff85d6-w4q4l                   0/1     Running     0          7s   

Additional context / logs:

• Validated with ingress, hostport, nodeport and ran though dual-stack testing
• Tested upgrade scenario (v1.23.9+k3s1 -> d04af60) and observed expected outcome