Ansible inventory: replace issues - ansible

Question

I have an inventory like this:
[all:vars]
env_cidr_prefix='172.25'
antother_var="foo"
[VPN_SERVER]
vpn-server ansible_host="{{ env_cidr_prefix}}.0.1"
During ansible playbook, the inventory holds only private ip address.
I wan't to replace the content of "ansible_host=" with the public ip
Example of a playbook:
- name: grab the vpn public_ip
set_fact: PUBLIC_IP="{{ instance_eip.public_ip }}"
when: inventory_hostname |search("vpn-server")
- name: update inventory with the vpn public ip
replace:
path: "{{ inventory_file }}"
regexp: "{{ ansible_host }}"
replace: "{{ PUBLIC_IP }}"
when: inventory_hostname |search("vpn-server")
if
ansible_host="172.25.0.1"
the replace module will work correctly.
but this fails
ansible_host="{{ env_cidr_prefix}}.0.1"
debug output:
ok: [vpn-server] => {
"changed": false,
"invocation": {
"module_args": {
"after": null,
"attributes": null,
"backup": false,
"before": null,
"content": null,
"delimiter": null,
"directory_mode": null,
"encoding": "utf-8",
"follow": false,
"force": null,
"group": null,
"mode": null,
"owner": null,
"path": "/home/toluna/ansible/openvpn/env.properties",
"regexp": "172.25.0.11",
"remote_src": null,
"replace": "1.1.1.1",
"selevel": null,
"serole": null,
"setype": null,
"seuser": null,
"src": null,
"unsafe_writes": null,
"validate": null
}
},
"msg": ""
}
Note, I cant use the add_host module since the playbooks are running in different stages
Is there a better way to do it ?
Thanks

Answer 1

OK, after testing it I guess I understand what are you trying to achieve.
Several parts here:
The inventory file is like this:
vpn-server ansible_host="{{ env_cidr_prefix}}.0.1"
And you are trying to replace 172.25.0.1 literal which doesn't exist in your file. You have "{{ env_cidr_prefix}}.0.1" and not 172.25.0.1.
Options:
If you want to replace that way, you can use a Jinja2 file in your role, replace the variable and the inventory file the same way you are trying.
Override the /etc/hosts file of your Jenkins (I really don't like too much) and play with the host name.
Play with your hosts variable in the playbook like:
Hosts Playbooks:
- name : Test
hosts: "{{ variable_vpn_ip | default('vpn-server') }}"
And call it reading from a variable that you will change ad-hoc or:
ansible-playbook play.yml -e "variable_vpn_ip=172.25.0.1"