# Variable namespacing

**URL:** <https://forum.ansible.com/t/variable-namespacing/24806>\
**Category:** Ansible Project\
**Created:** [June 22, 2017, 11:01pm UTC](https://forum.ansible.com/t/variable-namespacing/24806 "2017-06-22T23:01:42Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Ben\_Mildren](https://avatars.discourse-cdn.com/v4/letter/b/cdc98d/32.png) [@Ben\_Mildren](https://forum.ansible.com/u/Ben_Mildren)\
**Post date:** [June 22, 2017, 11:01pm UTC](https://forum.ansible.com/t/variable-namespacing/24806/1 "2017-06-22T23:01:42Z")

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When wanting to namespace variables in a role, is it typical to use a hash, or a prefix? Is there a best practice for this?

e.g.

role\_name\_var\_one: 1  
role\_name\_var\_two: 2  
role\_name\_var\_three: 3

or

role\_name:  
var\_one: 1  
var\_two: 2  
var\_three: 3

---

<div class="post-metadata">

**Author:** ![Josh\_Smift1](https://avatars.discourse-cdn.com/v4/letter/j/bcef8e/32.png) [@Josh\_Smift1](https://forum.ansible.com/u/Josh_Smift1)\
**Post date:** [June 27, 2017, 6:32pm UTC](https://forum.ansible.com/t/variable-namespacing/24806/2 "2017-06-27T18:32:27Z")

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> When wanting to namespace variables in a role, is it typical to use a  
> hash, or a prefix? Is there a best practice for this?

There are pros and cons either way. Off the top of my head, using a hash  
lets you iterate over it easily, and IMHO looks nicer; but you can't (as  
far as I know) add elements to it in different places in your inventory.  
If you have a hash of elements that you want defined on all hosts, and you  
then want to add another element to be defined only on a particular group  
of hosts, I don't think there's a way to do that. That's easy with  
prefixes; but then it's harder to loop through the prefix-ed variables.

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