原因：master節點的token過期了
解決：重新生成新token
在master重新生成token
# kubeadm token create
424mp7.nkxx07p940mkl2nd
# openssl x509 -pubkey -in /etc/kubernetes/pki/ca.crt | openssl rsa -pubin -outform der 2>/dev/null | openssl dgst -sha256 -hex | sed 's/^.* //'
d88fb55cb1bd659023b11e61052b39bbfe99842b0636574a16c76df186fd5e0d
Node節點重新join就可以了
kubeadm join 192.168.169.21:6443 –token 424mp7.nkxx07p940mkl2nd \
--discovery-token-ca-cert-hash sha256:d88fb55cb1bd659023b11e61052b39bbfe99842b0636574a16c76df186fd5e0d