No IP information in hostvars

Question

My Playbook:

- hosts: master
  gather_facts: True
  become: True
  tasks:
    - set_fact: headnode={{ ansible_all_ipv4_addresses[0] }}

- hosts: slave
  become: True
  tasks:
    - debug: msg={{ hostvars.master }}

And no fact headnode there. Am I missing something? Also, hostvars.master doesn't contain ['ansible_eth0'] So is all the documentation wrong?

This doesn't work also: hostvars['master ']['ansible_eth0']['ipv4']['address']
And this: hostvars[groups['master'][0]]['ansible_eth0']

http://docs.ansible.com/ansible/playbooks_variables.html#registered-variables

hostvars.master:

ok: [slave0] => {
    "msg": {
        "ansible_check_mode": false,
        "ansible_ssh_host": "xxx.westeurope.cloudapp.azure.com",
        "ansible_ssh_port": 22,
        "ansible_ssh_private_key_file": "/root/.ssh/id_rsa",
        "ansible_ssh_user": "vagrant",
        "ansible_version": {
            "full": "2.2.2.0",
            "major": 2,
            "minor": 2,
            "revision": 2,
            "string": "2.2.2.0"
        },
        "group_names": [
            "master"
        ],
        "groups": {
            "all": [
                "master",
                "slave0"
            ],
            "master": [
                "master"
            ],
            "slave": [
                "slave0"
            ],
            "ungrouped": []
        },
        "inventory_dir": "/xxx/.vagrant/provisioners/ansible/inventory",
        "inventory_file": null,
        "inventory_hostname": "master",
        "inventory_hostname_short": "master",
        "omit": "__omit_place_holder__fb9f90a73039d94f14c1a1f0af132f1c36b9fb4a",
        "playbook_dir": "/xxx/ansible"
    }
}

Answer 1

The - debug: msg={{ hostvars.master }} task shows only facts available from the inventory file. It does not contain the IP address nor quite a number of other facts that should be gathered from the remote machine by the regular setup module.

Now, as you seemingly run the playbook in Vagrant provisioning, it likely runs the playbook two times, first on master only, then on slave0 only. Vagrant by default passes a --limit argument to Ansible limiting the scope to the currently-provisioned machine only.

In result, when the playbook is being executed against slave0 , the first play (set to run on hosts: master ) is not executed and the facts from hosts belonging to the master group (in this case from the host also named master ) are not gathered.

---

You can either change the scope of the provisioning for the slave0 machine in Vagrantfile by setting ansible.limit = 'all' .

Or you can run ansible-playbook afterwards pointing to the Vagrant-generated inventory file.