How to authenticate hosts with Ansible? - ansible

Question

My hosts file
[all]
192.168.77.10
192.168.77.11
192.1680.77.12
And here is my playbook.yml
---
- hosts: all
tasks:
- name: Add the Google signing key
apt_key : url=https://packages.cloud.google.com/apt/doc/apt-key.gpg state=present
- name: Add the k8s APT repo
apt_repository: repo='deb http://apt.kubernetes.io/ kubernetes-xenial main' state=present
- name: Install packages
apt :
name: "{{ packages }}"
vars:
packages:
- vim
- htop
- tmux
- docker.io
- kubelet
- kubeadm
- kubectl
- kubernetes-cni
When I run
ansible-playbook -i hosts playbook.yml
unexpected authentication problem occurs.
The authenticity of host '192.168.77.11 (192.168.77.11)' can't be established.
ECDSA key fingerprint is SHA256:mgX/oadP2cL6g33u7xzrEblvga9CGfpW13K2YUdeKsE.
Are you sure you want to continue connecting (yes/no)? The authenticity of host '192.168.77.10 (192.168.77.10)' can't be established.
ECDSA key fingerprint is SHA256:ayWHzp/yquIuQxw7MKGR0+NbtrzHY86Z8PdIPv7r6og.
Are you sure you want to continue connecting (yes/no)? fatal: [192.1680.77.12]: UNREACHABLE! => {"changed": false, "msg": "Failed to connect to the host via ssh: ssh: Could not resolve hostname 192.1680.77.12: Name or service not known\r\n", "unreachable": true}
^C [ERROR]: User interrupted execution
I am following the example from DevOps book,I reproduced the original code. MY OS is Ubuntu 18.04.
telnet hosts
telnet: could not resolve hosts/telnet: Temporary failure in name resolution
VM ls output
vagrant#ubuntu-bionic:~$ ls
hosts playbook.retry playbook.yml
I edited /etc/ansible/ansible.cfg by ading False option.
Anyway it does not work again
fatal: [192.1680.77.12]: UNREACHABLE! => {"changed": false, "msg": "Failed to connect to the host via ssh: ssh: Could not resolve hostname 192.1680.77.12: Name or service not known\r\n", "unreachable": true}
fatal: [192.168.77.10]: UNREACHABLE! => {"changed": false, "msg": "Failed to connect to the host via ssh: Warning: Permanently added '192.168.77.10' (ECDSA) to the list of known hosts.\r\nvagrant#192.168.77.10: Permission denied (publickey).\r\n", "unreachable": true}
fatal: [192.168.77.11]: UNREACHABLE! => {"changed": false, "msg": "Failed to connect to the host via ssh: Warning: Permanently added '192.168.77.11' (ECDSA) to the list of known hosts.\r\nvagrant#192.168.77.11: Permission denied (publickey).\r\n", "unreachable": true}
to retry, use: --limit #/home/vagrant/playbook.retry
PLAY RECAP *************************************************************************************************************************************************************************************************
192.168.77.10 : ok=0 changed=0 unreachable=1 failed=0
192.168.77.11 : ok=0 changed=0 unreachable=1 failed=0
192.1680.77.12 : ok=0 changed=0 unreachable=1 failed=0
How to resolve this issue?

Answer 1

You have several options. One is of course to SSH to the hosts and add them to the known hosts files of your Ansible servers. Another option is to set the environment variable ANSIBLE_HOST_KEY_CHECKING to false. A third option is to use the ansible.cfg config file:
[defaults]
host_key_checking = False
See the official documentation.