Grains refresh/reload failed

I'm trying to reload the minion grains during a sls run with no success.
I have tried to use:

• reload_grains: True
• saltutil.grains_refresh
• salt service.running restart (using the watch statement)

Using each of the above function I failed to reload the grains during the state run.

Consider the following example:

before:
  cmd.run:
    - name: echo "{{ grains['dns'] }}"

echo "domain test" >> /etc/resolv.conf:
  cmd.run: []

after:
  cmd.run:
    - name: echo "{{ grains['dns'] }}"

At the before id I expect the domain field to be empty while on the after id I expect that the domain field would containtest
Another example, when i file.managed the grains.conf file I want that the grains change will take affect on the current run.

How can I achieve that?

I'm running on Ubuntu 16.04 with salt-minion and salt-master version 3000.3

Start by tracing how grains are loaded during cmd.run state execution, then compare the behavior of reload_grains, saltutil.grains_refresh, service.running, and file.managed. Verify whether changes to /etc/resolv.conf or grains.conf can affect later states in the same run, and define done as the after state observing the updated grain value.