ansible-host-example.yaml

#!/usr/bin/env ansible-playbook -i hosts
---
- hosts: all
  gather_facts: no
  tasks:
  - name: values without gather_facts
    debug:
      msg: |
          ansible_host = {{ ansible_host }}
          ansible_hostname = {{ ansible_hostname | default('*undefined*') }}
          inventory_hostname = {{ inventory_hostname | default('*undefined*') }}

  - name: "values without gather_facts and with delegate_to: localhost"
    debug:
      msg: |
          ansible_host = {{ ansible_host }}
          ansible_hostname = {{ ansible_hostname | default('*undefined*') }}
          inventory_hostname = {{ inventory_hostname | default('*undefined*') }}
    delegate_to: localhost

- hosts: localhost
  gather_facts: no
  tasks:
  - name: looping example run on localhost
    debug:
      msg: |
          ansible_host = {{ ansible_host }}
          ansible_hostname = {{ ansible_hostname | default('*undefined*') }}
          inventory_hostname = {{ inventory_hostname | default('*undefined*') }}
          hostvars['{{ item }}']['ansible_hostname'] = {{ hostvars[item]['ansible_hostname'] | default('*undefined*') }}
          hostvars['{{ item }}']['ansible_host'] = {{ hostvars[item]['ansible_host'] | default('*undefined*') }}
          hostvars['{{ item }}']['inventory_hostname'] = {{ hostvars[item]['inventory_hostname'] | default('*undefined*') }}
    with_items: "{{ groups['all'] }}"

output.log

PLAY [all] *************************************************************************************************************

TASK [values without gather_facts] *************************************************************************************
Thursday 09 August 2018  10:51:20 +0100 (0:00:00.055)       0:00:00.055 ******* 
ok: [undercloud] => {}

MSG:

ansible_host = localhost
ansible_hostname = *undefined*
inventory_hostname = undercloud


ok: [centos-7-rax-iad-0001216943] => {}

MSG:

ansible_host = 192.168.24.4
ansible_hostname = *undefined*
inventory_hostname = centos-7-rax-iad-0001216943


ok: [centos-7-rax-iad-0001216958] => {}

MSG:

ansible_host = 192.168.24.3
ansible_hostname = *undefined*
inventory_hostname = centos-7-rax-iad-0001216958



TASK [values without gather_facts and with delegate_to: localhost] *****************************************************
Thursday 09 August 2018  10:51:20 +0100 (0:00:00.081)       0:00:00.136 ******* 
ok: [centos-7-rax-iad-0001216943 -> localhost] => {}

MSG:

ansible_host = 192.168.24.4
ansible_hostname = *undefined*
inventory_hostname = centos-7-rax-iad-0001216943


ok: [undercloud -> localhost] => {}

MSG:

ansible_host = localhost
ansible_hostname = *undefined*
inventory_hostname = undercloud


ok: [centos-7-rax-iad-0001216958 -> localhost] => {}

MSG:

ansible_host = 192.168.24.3
ansible_hostname = *undefined*
inventory_hostname = centos-7-rax-iad-0001216958



PLAY [localhost] *******************************************************************************************************

TASK [looping example run on localhost] ********************************************************************************
Thursday 09 August 2018  10:51:20 +0100 (0:00:00.059)       0:00:00.196 ******* 
ok: [localhost] => (item=None) => {}

MSG:

ansible_host = 127.0.0.1
ansible_hostname = *undefined*
inventory_hostname = localhost
hostvars['centos-7-rax-iad-0001216943']['ansible_hostname'] = *undefined*
hostvars['centos-7-rax-iad-0001216943']['ansible_host'] = 192.168.24.4
hostvars['centos-7-rax-iad-0001216943']['inventory_hostname'] = centos-7-rax-iad-0001216943


ok: [localhost] => (item=None) => {}

MSG:

ansible_host = 127.0.0.1
ansible_hostname = *undefined*
inventory_hostname = localhost
hostvars['undercloud']['ansible_hostname'] = *undefined*
hostvars['undercloud']['ansible_host'] = localhost
hostvars['undercloud']['inventory_hostname'] = undercloud


ok: [localhost] => (item=None) => {}

MSG:

ansible_host = 127.0.0.1
ansible_hostname = *undefined*
inventory_hostname = localhost
hostvars['centos-7-rax-iad-0001216958']['ansible_hostname'] = *undefined*
hostvars['centos-7-rax-iad-0001216958']['ansible_host'] = 192.168.24.3
hostvars['centos-7-rax-iad-0001216958']['inventory_hostname'] = centos-7-rax-iad-0001216958



PLAY RECAP *************************************************************************************************************
centos-7-rax-iad-0001216943 : ok=2    changed=0    unreachable=0    failed=0   
centos-7-rax-iad-0001216958 : ok=2    changed=0    unreachable=0    failed=0   
localhost                  : ok=1    changed=0    unreachable=0    failed=0   
undercloud                 : ok=2    changed=0    unreachable=0    failed=0   

Thursday 09 August 2018  10:51:20 +0100 (0:00:00.070)       0:00:00.267 ******* 
=============================================================================== 
values without gather_facts ------------------------------------------------------------------------------------- 0.08s
looping example run on localhost -------------------------------------------------------------------------------- 0.07s
values without gather_facts and with delegate_to: localhost ----------------------------------------------------- 0.06s
Playbook run took 0 days, 0 hours, 0 minutes, 0 seconds