EmberJS config prod img src url

 Ember      : 1.13.6
 Ember Data : 1.13.7

I need to be able to set a global property and use it inside my .hbs files. Lets say for production I need serve images from another server but developing locally they can be severed relative to the project.

<img src="/spinner.gif" alt="Loading..."/>

How can I set a global property or config and use it inside my .hbs files?