[angularjs] Conditionally change img src based on model data

Instead of src you need ng-src.

AngularJS views support binary operators

condition && true || false

So your img tag would look like this

<img ng-src="{{interface == 'UP' && 'green-checkmark.png' || 'big-black-X.png'}}"/>

Note : the quotes (ie 'green-checkmark.png') are important here. It won't work without quotes.

plunker here (open dev tools to see the produced HTML)