apps.sls

"api_app": &api_app
    ...

"client_app": &client_app
    ...

error.txt

[CRITICAL] Failed to load grains defined in grain file vizibl_config.vizibl_config in function <function vizibl_config at 0x7f09e1c07ed8>, error:
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/salt/loader.py", line 525, in grains
    ret = fun()
  File "/var/cache/salt/minion/extmods/grains/vizibl_config.py", line 7, in vizibl_config
NameError: global name '__salt__' is not defined

grain.sls

#!/usr/bin/env python


def vizibl_config():

    grains = {}
    node_id = __salt__['core.id_']()['id']

    if node_id.startswith('prod'):
        grains['VIZIBL_CONFIG'] = 'Prod'
    elif node_id.startswith('stage'):
        grains['VIZIBL_CONFIG'] = 'Stage'
    elif node_id.startswith('sandbox'):
        grains['VIZIBL_CONFIG'] = 'Sandbox'
    elif node_id.startswith('qa'):
        grains['VIZIBL_CONFIG'] = 'QA'
    elif node_id.startswith('preprod'):
        grains['VIZIBL_CONFIG'] = 'PreProd'
    else:
        grains['VIZIBL_CONFIG'] = 'Dev'

    return grains

live.sls

{% include "pyapps/apps.sls" %}

pyapps:

  "foo":

    <<: *api_app

  "bar":

    <<: *client_app