# Variable used to lookup inventory value **URL:** \ **Category:** Ansible Project\ **Created:** [November 28, 2013, 12:48am UTC](https://forum.ansible.com/t/variable-used-to-lookup-inventory-value/14021 "2013-11-28T00:48:33Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Gonzalo\_Servat](https://avatars.discourse-cdn.com/v4/letter/g/71c47a/32.png) [@Gonzalo\_Servat](https://forum.ansible.com/u/Gonzalo_Servat)\ **Post date:** [November 28, 2013, 12:48am UTC](https://forum.ansible.com/t/variable-used-to-lookup-inventory-value/14021/1 "2013-11-28T00:48:33Z")
Hi All, This might be more of a Jinja question, but I couldn’t find an answer to this. Say I have an inventory value that stores the main NIC name and I want to lookup the IP address for it from a fact. How can this be done in the one line? Non working example: debug: msg=“ip address is {{ ansible\_{{ main\_nic }}.ipv4.address }}” GS ---
**Author:** ![Michael\_DeHaan2](https://avatars.discourse-cdn.com/v4/letter/m/da6949/32.png) [@Michael\_DeHaan2](https://forum.ansible.com/u/Michael_DeHaan2)\ **Post date:** [November 28, 2013, 12:52am UTC](https://forum.ansible.com/t/variable-used-to-lookup-inventory-value/14021/2 "2013-11-28T00:52:03Z")
You can build variables dynamically through hostvars, which is a hash of all variables, host by host: {{ hostvars[inventory\_hostname][“ansible\_” + main\_nic].ipv4.address }} inventory\_hostname is the name of the current host in the host loop. (Nesting templates in templates definitely will not work) ---
**Author:** ![Gonzalo\_Servat](https://avatars.discourse-cdn.com/v4/letter/g/71c47a/32.png) [@Gonzalo\_Servat](https://forum.ansible.com/u/Gonzalo_Servat)\ **Post date:** [November 28, 2013, 12:54am UTC](https://forum.ansible.com/t/variable-used-to-lookup-inventory-value/14021/3 "2013-11-28T00:54:05Z")
Perfect. That works. Again, thank you 🙂 GS ---
**Author:** ![edrozenberg](https://avatars.discourse-cdn.com/v4/letter/e/a6a055/32.png) [@edrozenberg](https://forum.ansible.com/u/edrozenberg)\ **Post date:** [May 1, 2014, 5:25pm UTC](https://forum.ansible.com/t/variable-used-to-lookup-inventory-value/14021/4 "2014-05-01T17:25:48Z")
Hi Michael, I tried using the {{ hostvars[inventory\_hostname] trick but that variable space does not include variables defined in a role such as “myrole/vars/main.yaml.” How can I programmatically reference variables defined within a role? Thank you, –Ed ---
**Author:** ![Michael\_DeHaan1](https://avatars.discourse-cdn.com/v4/letter/m/5e9695/32.png) [@Michael\_DeHaan1](https://forum.ansible.com/u/Michael_DeHaan1)\ **Post date:** [May 1, 2014, 9:28pm UTC](https://forum.ansible.com/t/variable-used-to-lookup-inventory-value/14021/5 "2014-05-01T21:28:34Z")
I believe there was a ticket about hostvars not including _all_ of the variables, which it should, that should now be resolved. If you still see this in 1.6 let me know. ---
**Author:** ![Michael\_Hoglan](https://avatars.discourse-cdn.com/v4/letter/m/a4c791/32.png) [@Michael\_Hoglan](https://forum.ansible.com/u/Michael_Hoglan)\ **Post date:** [October 15, 2014, 6:18pm UTC](https://forum.ansible.com/t/variable-used-to-lookup-inventory-value/14021/6 "2014-10-15T18:18:35Z")
Sorry to drag up an old thread, but this was one of the closer conversations out of the ones I found for what I was seeing. Looking through old tickets, it looks like there used to be an issue when accessing hostvars[inventory\_hostname] that you would not get all the vars associated with the host, such as ones added from add\_host call. I see this does work, however, if I debug just the hostvars itself (not hostvars[inventory\_hostname]) I don’t get the same results. The var does exist, and it can be used in plays, I mainly keep running into this as I am debugging and trying to see what vars exist for all hosts Given a host file of: > [launched] > > 10.0.3.234 test\_var=test > > 10.0.3.162 test\_var=test And a playbook of > * * * > > - name: Playbook testing inventory var debugging > > hosts: launched > > user: root > > gather\_facts: yes > > tasks: > > - name: Output inventory var > > debug: var=test\_var > > - name: Output inventory var from hostvars > > debug: var=hostvars[inventory\_hostname].test\_var > > - name: Output hostvars[inventory\_hostname] > > debug: var=hostvars[inventory\_hostname] > > - name: Output hostvars > > debug: var=hostvars The last debug for var=hostvars will not output the vars from the inventory file. The var exists, so this is kind of cosmetic, but it threw me off for a bit as I was working with add\_host for dynamic EC2 provisioning and wasn’t seeing the vars I was expecting when doing debug hostvars to look at all the vars for all hosts. > (ansible)[ec2-user@ip-10-0-0-226 playbooks]$ ansible-playbook -i launched test\_inventory\_var\_debug.yml > > PLAY [Playbook testing inventory var debugging] \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* > > GATHERING FACTS \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* > > ok: [10.0.3.162] > > ok: [10.0.3.234] > > TASK: [Output inventory var] \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* > > ok: [10.0.3.234] =\> { > > “test\_var”: “test” > > } > > ok: [10.0.3.162] =\> { > > “test\_var”: “test” > > } > > TASK: [Output inventory var from hostvars] \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* > > ok: [10.0.3.234] =\> { > > “hostvars[inventory\_hostname].test\_var”: “test” > > } > > ok: [10.0.3.162] =\> { > > “hostvars[inventory\_hostname].test\_var”: “test” > > } > > TASK: [Output hostvars[inventory\_hostname]] \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* > > ok: [10.0.3.234] =\> { > > “hostvars[inventory\_hostname]”: { > > “ansible\_all\_ipv4\_addresses”: [ > > “10.0.3.234” > > ], > > … > > “ansible\_virtualization\_type”: “xen”, > > **“group\_names”: [** > > **“launched”** > > **],** > > **“inventory\_hostname”: “10.0.3.234”,** > > **“inventory\_hostname\_short”: “10”,** > > **“module\_setup”: true,** > > **“test\_var”: “test”** > > } > > } > > ok: [10.0.3.162] =\> { > > “hostvars[inventory\_hostname]”: { > > “ansible\_all\_ipv4\_addresses”: [ > > “10.0.3.162” > > ], > > … > > “ansible\_virtualization\_type”: “xen”, > > **“group\_names”: [** > > **“launched”** > > **],** > > **“inventory\_hostname”: “10.0.3.162”,** > > **“inventory\_hostname\_short”: “10”,** > > **“module\_setup”: true,** > > **“test\_var”: “test”** > > } > > } > > TASK: [Output hostvars] \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* > > ok: [10.0.3.234] =\> { > > “hostvars”: { > > “10.0.3.162”: { > > “ansible\_all\_ipv4\_addresses”: [ > > “10.0.3.162” > > ], > > … > > “ansible\_virtualization\_type”: “xen”, > > “module\_setup”: true > > } > > } > > } > > ok: [10.0.3.162] =\> { > > “hostvars”: { > > “10.0.3.162”: { > > “ansible\_all\_ipv4\_addresses”: [ > > “10.0.3.162” > > ], > > … > > “ansible\_virtualization\_type”: “xen”, > > “module\_setup”: true > > } > > } > > } > > PLAY RECAP \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* > > 10.0.3.162 : ok=5 changed=0 unreachable=0 failed=0 > > 10.0.3.234 : ok=5 changed=0 unreachable=0 failed=0 Anyways, let me know if I misunderstand this or if there is a different var to be looking at for the inventory vars. I can open an issue ticket also. Thanks! Michael