How to change IP address of k3s

By default, as k3s operates in the local host, it is not possible to connect from other host.

To get the server Ip address,

$ kubectl config view --raw |grep server
    server: https://127.0.0.1:6443

The listening server IP address can be specified by giving parameter in running the k3s binary.

K3s configuration is on /etc/systemd/system/k3s.service

$ cat /etc/systemd/system/k3s.service
[Unit]
Description=Lightweight Kubernetes
Documentation=https://k3s.io
Wants=network-online.target
After=network-online.target

[Install]
WantedBy=multi-user.target

[Service]
Type=notify
EnvironmentFile=/etc/systemd/system/k3s.service.env
KillMode=process
Delegate=yes
# Having non-zero Limit*s causes performance problems due to accounting overhead
# in the kernel. We recommend using cgroups to do container-local accounting.
LimitNOFILE=1048576
LimitNPROC=infinity
LimitCORE=infinity
TasksMax=infinity
TimeoutStartSec=0
Restart=always
RestartSec=5s
ExecStartPre=-/sbin/modprobe br_netfilter
ExecStartPre=-/sbin/modprobe overlay
ExecStart=/usr/local/bin/k3s \
    server \
	'--write-kubeconfig-mode' \
	'644' \

Append server IP address of ExecStart option

ExecStart=/usr/local/bin/k3s \
    server \
        '--write-kubeconfig-mode' \
        '644' \
        --bind-address 0.0.0.0 \

Refer to the additional options Rancher Docs: K3s Server Configuration Reference

Then restart the k3s service

$ sudo systemctl restart k3s
$ sudo systemctl daemon-reload

Check again

$ kubectl config view --raw |grep server
    server: https://0.0.0.0:6443

To use the kube configuration from other host, change the server IP address of result of kubectl config view —raw to the host IP address of node.

#kubernetes/k3s