Ansible - read inventory hosts and variables to group_vars/all file

Question

I have a dummy doubt that keeps me stuck for a long time. I have a very banal inventory file with hosts and variables:

[lb]
10.112.84.122

[tomcat]
10.112.84         


        

Answer 1

If you want to refer one host define under /etc/ansible/host in a task or role, the bellow link might help:

https://www.middlewareinventory.com/blog/ansible-get-ip-address/

Answer 2

Just in case if the problem is still there, You can refer to ansible inventory through ‘hostvars’, ‘group_names’, and ‘groups’ ansible variables.

Example:

To be able to get ip addresses of all servers within group "mygroup", use the below construction:

- debug: msg="{{ hostvars[item]['ansible_eth0']['ipv4']['address'] }}" 
  with_items:
     - "{{ groups['mygroup'] }}"

Answer 3

Yes the example by nixlike works very well.

Inventory:

[docker-host]
myhost1 user=barbara
myhost2 user=heather

playbook:

---

- hosts: localhost
  connection: local         

     tasks:    
        - name: loop debug inventory hostnames
          debug: 
            msg: "the docker host is {{ item }}"
          with_inventory_hostnames: docker-host
        - name: loop debug items
          debug: 
            msg: "the docker host is {{ hostvars[item]['user'] }}"
          with_items: "{{ groups['docker-host'] }}"

output:

ansible-playbook ansible/tests/vars-test-local.yml

PLAY [localhost]

---

TASK [setup] ******************************************************************* ok: [localhost]

TASK [loop debug inventory hostnames] ****************************************** ok: [localhost] => (item=myhost2) => { "item": "myhost2", "msg": "the docker host is myhost2" } ok: [localhost] => (item=myhost1) => { "item": "myhost1", "msg": "the docker host is myhost1" }

TASK [loop debug items] ******************************************************** ok: [localhost] => (item=myhost1) => { "item": "myhost1", "msg": "the docker host is barbara" } ok: [localhost] => (item=myhost2) => { "item": "myhost2", "msg": "the docker host is heather" }

PLAY RECAP ********************************************************************* localhost : ok=3 changed=0 unreachable=0
failed=0

thanks!

Answer 4

- name: host
   debug: msg="{{ item }}" 
   with_items:
    - "{{ groups['tests'] }}"

This piece of code will give the message:

'10.112.84.122'
'10.112.84.124'

as groups['tests'] basically return a list of unique ip addresses ['10.112.84.122','10.112.84.124'] whereas groups['tomcat'][0] returns 10.112.84.124.

Answer 5

Considering your previous example:

inventory file:

[db]
10.112.83.37

group_vars/all

data_base_url=jdbc:oracle:thin:@{{ db }}:1521/ssdenwdb

template file:

oracle_url = {{ data_base_url }}

You might want to replace your group_vars/all with

data_base_url="jdbc:oracle:thin:@{{ groups['db'][0] }}:1521/ssdenwdb"

Answer 6

If you want to have your vars in files under group_vars, just move them here. Vars can be in the inventory ([group:vars] section) but also (and foremost) in files under group_vars or hosts_vars.

For instance, with your example above, you can move your vars for group tests in the file group_vars/tests :

Inventory file :

[lb]
10.112.84.122

[tomcat]
10.112.84.124

[jboss5]
10.112.84.122

...

[tests:children]
lb
tomcat
jboss5

[default:children]
tests

group_vars/tests file :

data_base_user=NETWIN-4.3
data_base_password=NETWIN
data_base_encrypted_password=
data_base_host=10.112.69.48
data_base_port=1521
data_base_service=ssdenwdb
data_base_url=jdbc:oracle:thin:@10.112.69.48:1521/ssdenwdb