fatal: [controller2]: FAILED! => {"msg": "'ansible.vars.hostvars.HostVarsVars object' has no attribute 'kubeadm_init'"}

This error message suggests that there is no variable named 'kubeadm_init' in the hostvars for the 'controller2' host. This could be due to a typo, a missing variable declaration, or a failure to properly define the variable in your playbook or inventory file. Double-check your syntax and ensure that the variable is properly set for the 'controller2' host.