Unable to join worker nodes to the cluster: error execution phase preflight: couldn't validate the identity of the API Server

[cmartinio]

I am getting an error in the setup stage (preflight check) no route to host. After running it with --v to check the stacktrace, I see the message saying: [discovery] Failed to request cluster-info, will try again: Get

• I used kubectl apply -f https://raw.githubusercontent.com/projectcalico/calico/v3.25.0/manifests/calico.yaml on the master node for calico installation.

[lovemasta41]

How did you run kubeadm init ? With or without pod cidr ? My calico pods are not even starting it’s in crashloopbackoff state? Did you face same issue ?

[lovemasta41]

Follow the simple method and check my issue.

[zenlinux121]

I faced the same error when using Virtualbox after setting up the VMs using Ubuntu 22.04 LTS as described in the PDF. The error was fixed when I changed the Network card type from NAT to bridge and with fixed IP addresses to avoid changes from DHCP. The error happened because the communication between VMs was not possible, except port 22, when NAT is type is set. After changing the network adapter to bridge type and starting from zero the procedure to install vanilla Kubernetes everything worked as expected.
Also I tried adding another network adapter but it failed as well because the TLS certificate is only applied to one network adapter when doing kubeadm init. I guess there is an option to generate the TLS certificate to all network adapters for kubeadm init.

Thank you.