Disabling Host key checking on playbook definition

Question

Regarding How to set host_key_checking=false in ansible inventory file? I wanted to know if it is possible to change this setting on the playbook definition.

My playbook is called automatically and I cannot use export to set the ENV variable before starting the playbook.

This is what I tried:

---
- hosts: localhost
  environment:
    ANSIBLE_HOST_KEY_CHECKING: false
  roles:
    - including_vars

The problem is that if I add a host during the playbook tasks I get the following error:

UNREACHABLE! => {"changed": false, "msg": "Failed to connect to the host via ssh: Host key verification failed.\r\n", "unreachable": true}

This seems to indicate that the environment variable is not used.

Any idea on how I could change this setting on runtime?

techraf · Accepted Answer · 2018-08-07T19:36:32.123

5

You can set ansible_host_key_checking / ansible_ssh_host_key_checking in the vars section of the play:

---
- hosts: localhost
  vars:
    ansible_host_key_checking: false
  roles:
    - including_vars

Important: when testing with pipelining enabled, give SSH time to expire the persistent connection, otherwise changed settings might not yet be applied.

You could also create an in-memory inventory with host_key_checking and run your real plays against that inventory (this would also work with Ansible versions older than 2.5):

----
- hosts: localhost
  connection: local
  gather_facts: false
  tasks:
    - add_host:
        name: my_host
        ansible_host: myhost.example.com
        host_key_checking: false

- hosts: my_host
  tasks:
    - ping:

edited Aug 07 '18 at 19:36

answered Aug 07 '18 at 19:00

techraf

64,883
27
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6

I tried with both proposals but in the end the only thing that worked was `ansible_ssh_extra_args: "-o StrictHostKeyChecking=no"` – djuarezg Aug 08 '18 at 13:07
So you must have done something wrong in your tries. – techraf Aug 08 '18 at 13:08
there seems to be an open bug on this problem: https://github.com/ansible/ansible/issues/49254 – Kenny Ho May 21 '20 at 23:40

score 0 · Answer 2 · answered Oct 01 '19 at 16:00

0

Shouldn't you have used env: instead of environment:? e.g.,

---
- hosts: localhost
  env:
    ANSIBLE_HOST_KEY_CHECKING: false
  roles:
    - including_vars

answered Oct 01 '19 at 16:00

robocoder

233
4
9

Disabling Host key checking on playbook definition

2 Answers2