k3s server 无法 kubectl get nodes 到 k3s agent

ERROR

...
[INFO]  env: Creating environment file /etc/systemd/system/k3s-agent.service.env
[INFO]  systemd: Creating service file /etc/systemd/system/k3s-agent.service
[INFO]  systemd: Enabling k3s-agent unit
[INFO]  systemd: Starting k3s-agent
root@192-168-1-102:~# systemctl status k3s-agent
● k3s-agent.service - Lightweight Kubernetes
   Loaded: loaded (/etc/systemd/system/k3s-agent.service; enabled; vendor preset: enabled)
   Active: activating (auto-restart) (Result: exit-code) since Fri 2021-04-23 16:46:30 CST; 1s ago
     Docs: https://k3s.io
  Process: 3591 ExecStartPre=/sbin/modprobe br_netfilter (code=exited, status=0/SUCCESS)
  Process: 3592 ExecStartPre=/sbin/modprobe overlay (code=exited, status=0/SUCCESS)
  Process: 3593 ExecStart=/usr/local/bin/k3s agent (code=exited, status=1/FAILURE)
 Main PID: 3593 (code=exited, status=1/FAILURE)
root@192-168-1-102:~# /usr/local/bin/k3s-agent-uninstall.sh

Process: 3593 ExecStart=/usr/local/bin/k3s agent (code=exited, status=1/FAILURE)

检查发现使用 sudo su 有异常

pi@192-168-1-102:~ $ sudo su
sudo: unable to resolve host 192-168-1-102: Name or service not known
root@192-168-1-102:/home/pi#

sudo: unable to resolve host 192-168-1-102: Name or service not known

修改 hostname 步骤有问题

• 先前使用如下方法修改 hostname

root@pi-102:/home/pi# nano /etc/hostname

/etc/hostname
pi-102

• 但 hosts 文件内 hostname 没变

root@pi-102:/home/pi# nano /etc/hosts

/etc/hosts
27.0.0.1        localhost
::1             localhost ip6-localhost ip6-loopback
ff02::1         ip6-allnodes
ff02::2         ip6-allrouters

127.0.1.1       raspberrypi

• /etc/hosts 修改为

/etc/hosts
27.0.0.1        localhost
::1             localhost ip6-localhost ip6-loopback
ff02::1         ip6-allnodes
ff02::2         ip6-allrouters

127.0.1.1       pi-102

重新部署 k3s agent 并检查状态

root@pi-102:~# systemctl status k3s-agent
● k3s-agent.service - Lightweight Kubernetes
   Loaded: loaded (/etc/systemd/system/k3s-agent.service; enabled; vendor preset: enabled)
   Active: active (running) since Fri 2021-04-23 17:00:30 CST; 58s ago
     Docs: https://k3s.io
  Process: 1004 ExecStartPre=/sbin/modprobe br_netfilter (code=exited, status=0/SUCCESS)
  Process: 1007 ExecStartPre=/sbin/modprobe overlay (code=exited, status=0/SUCCESS)
 Main PID: 1008 (k3s-agent)
    Tasks: 31
   Memory: 184.7M
   CGroup: /system.slice/k3s-agent.service
           ├─1008 /usr/local/bin/k3s agent
           └─1029 containerd 

Apr 23 17:01:19 pi-102 k3s[1008]: I0423 17:01:19.221111    1008 shared_informer.go:240] Waiting for caches to sync for endpoint slice config
Apr 23 17:01:19 pi-102 k3s[1008]: I0423 17:01:19.321267    1008 shared_informer.go:247] Caches are synced for service config
Apr 23 17:01:19 pi-102 k3s[1008]: I0423 17:01:19.321412    1008 shared_informer.go:247] Caches are synced for endpoint slice config

在 k3s server 中测试

root@192-168-1-100:~# kubectl get nodes
NAME              STATUS   ROLES                  AGE     VERSION
192-168-1-100     Ready    control-plane,master   7h26m   v1.20.6+k3s1
raspberrypi-101   Ready    worker                 7h22m   v1.20.6+k3s1
pi-102            Ready    <none>                 30s     v1.20.6+k3s1

• 修改节点 pi-102 角色

root@192-168-1-100:~# kubectl label node pi-102 node-role.kubernetes.io/worker=worker
node/pi-102 labeled
root@192-168-1-100:~# kubectl get nodes
NAME              STATUS   ROLES                  AGE     VERSION
192-168-1-100     Ready    control-plane,master   7h27m   v1.20.6+k3s1
raspberrypi-101   Ready    worker                 7h23m   v1.20.6+k3s1
pi-102            Ready    worker                 98s     v1.20.6+k3s1

:-) 奇怪的错误