{% set acme = salt['grains.filter_by']({
    'default': {
        'package': 'letsacme',
        'user': 'acme',
        'home': '/var/lib/acme',
        'webroot': '/srv/www/acme/',
    }
}, base='default') %}

{% set acme = salt['grains.filter_by']({
    'default': {
        'package': 'acme-tiny',
        'user': 'acme',
        'home': '/var/lib/acme',
        'webroot': '/var/www/challenges/',
    }
}, base='default') %}

Switch to tiny-acme as ACME backend.
acme: Switch to tiny-acme as ACME backend.

This is done because tiny-acme is in the official repos.
