First way-
Note: you need to run all these commands on master/control plane node.
- Finding token-
kubeadm token list
“749p22.f2342qewnc6zu1cc”
2. Finding the CA cert hash-
openssl x509 -pubkey -in /etc/kubernetes/pki/ca.crt | openssl rsa -pubin -outform der 2>/dev/null | openssl dgst -sha256 -hex | sed 's/^.* //'