About "has no attribute" error

[espala]

Hello,

I am up to 3 instance on gce using terraform. I'm trying to create a kubernetes cluster on these 3 nodes. Until ansible, everything works fine. Servers open, firewall rules, network is complete.

I used the example of allinone. I always get the following error. Where am I making a mistake?

cat inventory

#xxx=public ip adresses

[kubernetes:children]
etcd
k8s_masters
k8s_nodes

[kubernetes:vars]
docker_version="18.06.0-ce"

[etcd]
x.x.x.x ansible_ssh_user=testuser
x.x.x.x ansible_ssh_user=testuser
x.x.x.x ansible_ssh_user=testuser

[k8s_masters]
x.x.x.x ansible_ssh_user=testuser

[k8s_nodes]
x.x.x.x ansible_ssh_user=testuser
x.x.x.x ansible_ssh_user=testuser

cat playbook.yml

- hosts: kubernetes
#  sudo: yes
  become: true
  become_user: root
  gather_facts: false
  tasks:
  - name: install python 2
    raw: test -e /usr/bin/python || (apt -y update && apt install -y python-minimal)
    changed_when: false

- hosts: kubernetes
#  sudo: yes
  become: true
  become_user: root
  roles:
#    - geerlingguy.docker
    - anmoel.kubernetes

my command;
export ANSIBLE_HOST_KEY_CHECKING=False && time ansible-playbook -i inventory playbook.yml -v

error message;

TASK [anmoel.kubernetes : /etc/kubernetes/kubeadm/clusterconfig.yaml] **********************************************************************************************************************************************************************************************************
fatal: [x.x.x.x]: FAILED! => {"changed": false, "msg": "AnsibleUndefinedVariable: 'ansible.vars.hostvars.HostVarsVars object' has no attribute 'ansible_host'"}
fatal: [x.x.x.x]: FAILED! => {"changed": false, "msg": "AnsibleUndefinedVariable: 'ansible.vars.hostvars.HostVarsVars object' has no attribute 'ansible_host'"}
fatal: [x.x.x.x]: FAILED! => {"changed": false, "msg": "AnsibleUndefinedVariable: 'ansible.vars.hostvars.HostVarsVars object' has no attribute 'ansible_host'"}
	to retry, use: --limit @.../playbook.retry


PLAY RECAP *********************************************************************************************************************************************************************************************************************************************************************
x.x.x.x             : ok=30   changed=14    unreachable=0    failed=1
x.x.x.x             : ok=30   changed=14    unreachable=0    failed=1
x.x.x.x             : ok=30   changed=14    unreachable=0    failed=1

[Matteo]

Seems related to this ansible issue: ansible/ansible#51727