[Release-1.27] - Agent node IP not replaced with Tailscale VPN IP

[manuelbuil]

Backport fix for Agent node IP not replaced with Tailscale VPN IP

• Agent node IP not replaced with Tailscale VPN IP #10064

[VestigeJ]

##Environment Details
Reproduced using VERSION=v1.27.14+k3s1
Validated using COMMIT=331ce7066667f650b3563de5ba1b1f363d00d68d

Infrastructure

• Cloud

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

Linux 5.14.21-150500.53-default x86_64 GNU/Linux
PRETTY_NAME="SUSE Linux Enterprise Server 15 SP5"

Config.yaml:

node-external-ip: 1.11.111.31
server: https://1.1.1.71:6443
token: YOUR_TOKEN_HERE
vpn-auth-file: /etc/rancher/k3s/vpn

Reproduction

$ curl https://get.k3s.io --output install-"k3s".sh
$ sudo chmod +x install-"k3s".sh
$ sudo groupadd --system etcd && sudo useradd -s /sbin/nologin --system -g etcd etcd
$ sudo modprobe ip_vs_rr
$ sudo modprobe ip_vs_wrr
$ sudo modprobe ip_vs_sh
$ sudo printf "on_oovm.panic_on_oom=0 \nvm.overcommit_memory=1 \nkernel.panic=10 \nkernel.panic_ps=1 \nkernel.panic_on_oops=1 \n" > ~/90-kubelet.conf
$ sudo cp 90-kubelet.conf /etc/sysctl.d/
$ sudo systemctl restart systemd-sysctl
$ get_tailscale //function posted below
$ sudo mkdir -p /etc/rancher/k3s/
$ sudo vim /etc/rancher/k3s/vpn
$ COMMIT=331ce7066667f650b3563de5ba1b1f363d00d68d
$ sudo INSTALL_K3S_COMMIT=$COMMIT INSTALL_K3S_EXEC=agent ./install-k3s.sh

Results:

Two identically configured agents join the primary node and you can see the difference in behavor in the output.
$ kgn

NAME               STATUS   ROLES                       AGE    VERSION                 INTERNAL-IP      EXTERNAL-IP      OS-IMAGE                              KERNEL-VERSION              CONTAINER-RUNTIME
ip-1-1-1-21        Ready    <none>                      38s    v1.27.14+k3s1           1.1.1.21         1.11.111.21     SUSE Linux Enterprise Server 15 SP5   5.14.21-150500.53-default   containerd://1.7.15-k3s1.27
ip-1-1-1-71        Ready    control-plane,etcd,master   101s   v1.27.14+k3s1           100.77.213.109   1.11.111.71     SUSE Linux Enterprise Server 15 SP5   5.14.21-150500.53-default   containerd://1.7.15-k3s1.27
ip-1-1-1-31        Ready    <none>                      20s    v1.27.14+k3s-331ce706   100.86.92.4      1.11.111.31     SUSE Linux Enterprise Server 15 SP5   5.14.21-150500.53-default   containerd://1.7.15-k3s1.27

get_tailscale() {
    curl -fsSL https://tailscale.com/install.sh -o install-ts.sh
    chmod +x install-ts.sh
    sudo ./install-ts.sh
}