Ansible – Supplying Hosts Value via Jinja Conditionals

ansiblejinja

I have an Ansible role that I want to execute on particular hosts based on a certain conditions.

I want to populate the hosts from Ansible Tower survey. Here's my playbook:

- name: HTTP Response Deploy Automation
  hosts: "{% if geo == 'LHR' %}'dblhr002' {% elif geo == 'SJC' %}'dbsjc003' {% endif %}"
  gather_facts: true
  roles:
    - http-response-deploy

I'm getting the following error when choosing LHR:

 [WARNING]: Could not match supplied host pattern, ignoring: 'dblhr002'

To note that, it doesn't work when I choose to omit the quotes around the hostnames.

TLDR; need to achieve the conditionals from Ansible as below:

if geo == "LHR": 
   hosts: dblhr002
if geo == "SJC":
   hosts: dbsjc003

Best Answer

What you have provided works fine, as long as dblhr002 is listed in inventory. Host patterns only match existing hosts, they do not add new hosts to the inventory.

ec2-user@pandora ~ $ cat test.yml 
- hosts: "{% if geo == 'LHR' %}'dblhr002' {% elif geo == 'SJC' %}'dbsjc003' {% endif %}"
  gather_facts: false
  tasks:
    - debug:
ec2-user@pandora ~ $ ANSIBLE_INVENTORY_ENABLED=host_list ansible-playbook ~/test.yml -e geo=LHR -i dblhr002,

PLAY [dblhr002] ****************************************************************

TASK [debug] *******************************************************************
ok: [dblhr002] => {
    "msg": "Hello world!"
}

PLAY RECAP *********************************************************************
dblhr002                   : ok=1    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0

If you need to dynamically add a host, use the add_host task in a separate play.

- hosts: localhost
  gather_facts: false
  tasks:
    - add_host:
        name: "{{ host_map[geo] }}"
        groups: target_host
      vars:
        host_map:
          LHR: dblhr002
          SJC: dbsjc003

- hosts: target_host
  gather_facts: false
  tasks:
    - debug:
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